Protective effects of glutathione on 5-fluorouracil-induced myelosuppression in mice

Metronomic capecitabine inhibits liver transplant rejection in rats by triggering recipients’ T cell ferroptosis

BACKGROUND

Capecitabine (CAP) is a classic antimetabolic drug and has shown potential antirejection effects after liver transplantation (LT) in clinical studies. Our previous study showed that metronomic CAP can cause the programmed death of T cells by inducing oxidative stress in healthy mice. Ferroptosis, a newly defined non-apoptotic cell death that occurs in response to iron overload and lethal levels of lipid peroxidation, is an important mechanism by which CAP induces cell death. Therefore, ferroptosis may also play an important role in CAP-induced T cell death and play an immunosuppressive role in acute rejection after trans-plantation.

AIM

To investigate the functions and underlying mechanisms of antirejection effects of metronomic CAP.

METHODS

A rat LT model of acute rejection was established, and the effect of metronomic CAP on splenic hematopoietic function and acute graft rejection was evaluated 7 d after LT. In vitro, primary CD3⁺ T cells were sorted from rat spleens and human peripheral blood, and co-cultured with or without 5-fluorouracil (5-FU) (active agent of CAP). The levels of ferroptosis-related proteins, ferrous ion concentration, and oxidative stress-related indicators were observed. The changes in mito-chondrial structure were observed using electron microscopy.

RESULTS

With no significant myelotoxicity, metronomic CAP alleviated graft injury (Banff score 9 vs 7.333, P < 0.001), prolonged the survival time of the recipient rats (11.5 d vs 16 d, P < 0.01), and reduced the infiltration rate of CD3⁺ T cells in peripheral blood (6.859 vs 3.735, P < 0.001), liver graft (7.459 vs 3.432, P < 0.001), and spleen (26.92 vs 12.9, P < 0.001), thereby inhibiting acute rejection after LT. In vitro, 5-FU, an end product of CAP metabolism, induced the degradation of the ferritin heavy chain by upregulating nuclear receptor coactivator 4, which caused the accumulation of ferrous ions. It also inhibited nuclear erythroid 2 p45-related factor 2, heme oxygenase-1, and glutathione peroxidase 4, eventually leading to oxidative damage and ferroptosis of T cells.

CONCLUSION

Metronomic CAP can suppress acute allograft rejection in rats by triggering CD3⁺ T cell ferroptosis, which makes it an effective immunosuppressive agent after LT.

Photobiomodulation therapy for thrombocytopenia by upregulating thrombopoietin expression via the ROS-dependent Src/ERK/STAT3 signaling pathway

BACKGROUND

Chemotherapy-induced thrombocytopenia (CIT) can increase the risk of bleeding, which may delay or prevent the administration of anticancer treatment schedules. Photobiomodulation therapy (PBMT), a non-invasive physical treatment, has been proposed to improve thrombocytopenia; however, its underlying regulatory mechanism is not fully understood.

OBJECTIVE

To further investigate the mechanism of thrombopoietin (TPO) in megakaryocytopoiesis and thrombopoiesis.

METHODS

Multiple approaches such as western blotting, cell transfection, flow cytometry, and animal studies were utilized to explore the effect and mechanism of PBMT on thrombopoiesis.

RESULTS

PBMT prevented a severe drop in platelet count by increasing platelet production, and then ameliorated CIT. Mechanistically, PBMT significantly upregulated hepatic TPO expression in a thrombocytopenic mouse model, which promoted megakaryocytopoiesis and thrombopoiesis. The levels of TPO mRNA and protein increased by PBMT via the Src/ERK/STAT3 signaling pathway in hepatic cells. Furthermore, the generation of the reactive oxygen species was responsible for PBMT-induced activation of Src and its downstream target effects.

CONCLUSIONS

Our research suggests that PBMT is a promising therapeutic strategy for the treatment of CIT.

Ganoderma lucidum Polysaccharide Enhanced the Antitumor Effects of 5-Fluorouracil against Gastric Cancer through Its Upregulation of NKG2D/MICA

5-Fluorouracil (5-Fu) is one of the frequently used first-line cytotoxic drugs for chemotherapy against gastric cancer. Chemotherapy and immunotherapy are currently the main methods for treating gastric cancer. Immunotherapy can enhance the antitumor effect of chemotherapy drugs at the same time reducing its toxicity. The combination of these two therapies to treat cancer has become a mainstay and has received increasing attention in clinical practice. Ganoderma lucidum polysaccharide (GLP) is isolated from the Ganoderma lucidum fruiting body. Studies have shown that GLP has antitumor effects, where GLP does not directly kill tumors, rather exerting its antitumor function by stimulating immune cells including natural killer (NK) cells and T cells. In this study, the antitumor effect of GLP combined with 5-Fu was studied in vivo. At the same time, the associated mechanism of GLP combined with 5-Fu in gastric cancer cell lines BGC823 and SGC7901 was investigated in vitro. The results showed that GLP could stimulate the killing effect of NK-92 cells on gastric cancer cell lines BGC823 and SGC7901 and synergistically enhance the toxic effects of NK-92 cells on gastric cancer cell lines BGC823 and SGC7901. Moreover, GLP could further promote the activity of NK-92 cells by activating the NK cell activating receptor NKG2D and its downstream DAP10/PI3K/ERK signaling pathway.

SEP enhanced the antitumor activity of 5-fluorouracil by up-regulating NKG2D/MICA and reversed immune suppression via inhibiting ROS and caspase-3 in mice

Chemotherapy and immunotherapy are the main remedies used in cancer treatment. Because immunotherapy can not only reduce the toxicity of chemotherapeutics but also enhance antitumor effects in vivo, combining these two therapies is a trend that continues to gain more attention in clinic. SEP, a polysaccharide isolated from Strongylocentrotus nudus egg, has been reported to display antitumor activity by stimulating immune cells, including NK and T cells, via TLR2 and TLR4. In the present study, the synergistic effect between SEP and 5-fluorouracil (5-FU), a traditional cytotoxic drug, in vitro and in vivo was investigated. The results obtained indicated that SEP alone stimulated NK-92 cytotoxicity and coordinated with 5-FU to augment the cytotoxicity of NK-92 cells against HepG-2 or A549 cells in vitro. SEP promoted NK-92 activity by stimulating NKG2D and its downstream DAP10/PI3K/Erk signaling pathway. Additionally, 5-FU could increase MICA expression on HepG-2 or A549 cells and prevent membrane MICA from shedding as soluble MICA, which were abrogated in the tumor cells transfected with ADAM 10 overexpression plasmid. Moreover, in H22- or Lewis lung cancer (LLC)-bearing mouse models, SEP reversed 5-FU-induced atrophy and apoptosis in both the spleen and bone marrow in vivo by suppressing ROS generation and caspase-3 activation. All of these results highlight the potential for the combination of SEP and 5-FU in cancer therapy in the future.

Pharmacogenetics of toxicity of 5-fluorouracil, doxorubicin and cyclophosphamide chemotherapy in breast cancer patients

The differences in patients' response to the same medication, toxicity included, are one of the major problems in breast cancer treatment. Chemotherapy toxicity makes a significant clinical problem due to decreased quality of life, prolongation of treatment and reinforcement of negative emotions associated with therapy. In this study we evaluated the genetic and clinical risk factors of FAC chemotherapy-related toxicities in the group of 324 breast cancer patients. Selected genes and their polymorphisms were involved in FAC drugs transport (ABCB1, ABCC2, ABCG2,SLC22A16), metabolism (ALDH3A1, CBR1, CYP1B1, CYP2C19, DPYD, GSTM1, GSTP1, GSTT1, MTHFR,TYMS), DNA damage recognition, repair and cell cycle control (ATM, ERCC1, ERCC2, TP53, XRCC1). The multifactorial risk models that combine genetic risk modifiers and clinical characteristics were constructed for 12 toxic symptoms. The majority of toxicities was dependent on the modifications in components of more than one pathway of FAC drugs, while the impact level of clinical factors was comparable to the genetic ones. For the carriers of multiple high risk factors the chance of developing given symptom was significantly elevated which proved the factor-dosage effect. We found the strongest associations between concurrent presence of clinical factors - overall and recurrent anemia, nephrotoxicity and early nausea and genetic polymorphisms in genes responsible for DNA repair, drugs metabolism and transport pathways. These results indicate the possibility of selection of the patients with expected high tolerance to FAC treatment and consequently with high chance of chemotherapy completion without the dose reduction, treatment delays and decline in the quality of life.

In Vivo Chemoprotective Activity of Bovine Dialyzable Leukocyte Extract in Mouse Bone Marrow Cells against Damage Induced by 5-Fluorouracil

Chemotherapy treatments induce a number of side effects, such as leukopenia neutropenia, peripheral erythropenia, and thrombocytopenia, affecting the quality of life for cancer patients. 5-Fluorouracil (5-FU) is wieldy used as myeloablative model in mice. The bovine dialyzable leukocyte extract (bDLE) or IMMUNEPOTENT CRP® (ICRP) is an immunomodulatory compound that has antioxidants and anti-inflammatory effects. In order to investigate the chemoprotection effect of ICRP on bone marrow cells in 5-FU treated mice, total bone marrow (BM) cell count, bone marrow colony forming units-granulocyte/macrophage (CFU-GM), cell cycle, immunophenotypification, ROS/superoxide and Nrf2 by flow cytometry, and histological and hematological analyses were performed. Our results demonstrated that ICRP increased BM cell count and CFU-GM number, arrested BM cells in G0/G1 phase, increased the percentage of leukocyte, granulocytic, and erythroid populations, reduced ROS/superoxide formation and Nrf2 activation, and also improved hematological levels and weight gain in 5-FU treated mice. These results suggest that ICRP has a chemoprotective effect against 5-FU in BM cells that can be used in cancer patients.

Echinacoside improves hematopoietic function in 5-FU-induced myelosuppression mice

AIMS

We aimed to investigate the effects of echinacoside (ECH) on hematopoietic function in 5-FU-induced bone marrow depression mice.

MAIN METHODS

In vitro, after stimulation with ECH, the proliferation ability of bone marrow (BM) cells and bone marrow stromal cells (BMSCs) derived from myelosuppression mice were assessed by CCK8 assay and morphology, respectively. In vivo, 5-FU-induced myelosuppression or control mice were intragastrically administrated with either ECH at 15 mg/kg or the equal volume of normal saline daily for 12 days before BM cells were isolated for colony-forming cell assay. Meanwhile, BMSCs were cultured for 4 weeks before cells were observed for growth pattern, cell culture supernatants were collected for GM-CSF secretion by ELISA, and RNA of the cells were extracted for EPO and GM-CSF RT-PCR. BM cells or BMSCs stimulated with ECH for 24 h or 48 h were collected for protein extraction and Western blotting.

KEY FINDINGS

ECH stimulated the growth of BM cells but not BMSCs derived from 5-FU treated mice. The intragastric administration of ECH in 5-FU treated mice could increase the number of total hematopoietic progenitor cells and GM progenitor cells to healthy control mice level, but not BFU progenitor cells. BMSCs from ECH treated myelosuppression mice grew more vigorously and expressed more GM-CSF, but not EPO. ECH activated the PI3K signaling pathway in 5-FU suppressed BM cells.

SIGNIFICANCE

ECH could improve the hematopoietic function of bone marrow in 5-FU-induced myelosuppression mice. ECH can be considered as an alternative effective therapy for patients during chemotherapy or HSC transplantation.

Glutathione protects human nucleus pulposus cells from cell apoptosis and inhibition of matrix synthesis

Abstract Cell death (apoptosis and necrosis) and extracellular matrix destruction induced by oxidative stress have been suggested to be closely involved in the process of disc degeneration. Glutathione, a natural peptide as a powerful antioxidant in human cytoplasm, plays an important role in protecting living cells. This study is to investigate whether glutathione could retard degenerated phenotypes in cultured disc cells. Human nucleus pulposus cells were isolated and cultured in alginate beads and subsequently treated with a pro-oxidant H2O2 alone or a pro-inflammatory cytokine IL-1β alone or either of them together with glutathione. It was shown that H2O2 dose-dependently promoted nucleus pulposus cell apoptosis detected by terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) staining and decreased mRNA levels of matrix proteins aggrecan and type II collagen determined by quantitative reverse transcription-polymerase chain reaction (RT-PCR). IL-1β could induce production of nitric oxide and decrease of proteoglycan, detected by the Griess reagent and the dimethyl methylene blue, respectively. The deleterious effects of either H2O2 or IL-1β could be efficiently prevented by glutathione. These results indicated that glutathione might be considered as an option for intervention of disc degeneration.

Myelophil, a mixture of Astragali Radix and Salviae Radix extract, moderates toxic side effects of fluorouracil in mice

AIM: To evaluate the efficacy of Myelophil, an extract containing Astragali Radix and Salviae Radix, for reducing complications induced by 5-fluorouracil (5-FU) in a gastrointestinal cancer model.

METHODS: We injected 5-FU into mice and then administered Myelophil to examine the ability of the drug to treat the side effects of 5-FU in mice. Peripheral blood counts, histological examinations, and colony-forming assays of bone marrow were conducted, followed by swimming tests and assessment of survival times.

RESULTS: Myelophil restored red and white blood cells and platelets in blood, and recovered cell density in bone marrow to levels comparable to those observed within the control group. In addition, Myelophil significantly increased colony-forming unit granulocyte-macrophage (CFU-GM) and CFU-erythroid (CFU-E) compared to the control group. We confirmed that interleukin-3 gene expression was upregulated by Myelophil in spleen cells. Myelophil administration also doubled the survival rate of mice that were severely myelosuppressed as a result of 5-FU injection at a lethal dose of 70%. Finally, the swimming performance of mice significantly improved as a result of Myelophil treatment.

CONCLUSION: These results provide experimental evidence in support of clinical applications of Myelophil to minimize 5-FU-induced myelosuppression and improve general post-chemotherapy health.

Protective effect of anthocyanin-rich extract from bilberry (Vaccinium myrtillus L.) against myelotoxicity induced by 5-fluorouracil

The toxicities associated with 5-fluorouracil (5-FU), a potent broad-spectrum chemotherapeutic agent, can not only affect the morbidity and the efficacy of chemotherapy but also limit its clinical use. The objective of this study is to investigate the effects of a commercial anthocyanin-rich extract from bilberry (AREB) against 5-FU-induced myelotoxicity in vivo, and against chemosensitivity to 5-FU in vitro. A single injection of 5-FU at 200 mg/kg induced severe peripheral erythrocytopenia, thrombocytopenia and leucopenia as well as hypocellularity of the spleen and bone marrow in C57BL/6 mice. Oral administration of 500 mg/kg of AREB for 10 days significantly increased the number of red blood cells, neutrophils, and monocytes in peripheral blood to 1.2-fold, 9-fold, and 6-fold, respectively, compared with those seen after treatment with 5-FU alone (p< 0.05-0.001). The hypocellularity of the spleen and bone marrow caused by 5-FU was also distinctly alleviated in the AREB-treated group. Furthermore, AREB treatment with 50 and 100 microg/ml as a monomeric anthocyanin did not interfere with, but rather enhanced the chemotherapeutic efficacy of 5-FU in vitro. These results suggest that AREB may have protective potential against 5-FU-induced myelotoxiciy and/or the ability to enhance the chemotherapeutic effectiveness of 5-FU.

Protective effect of (+)-catechin against 5-fluorouracil-induced myelosuppression in mice

The object of this study was to investigate the efficacy of (+)-catechin, which was isolated from Actinidia arguta Planch (Actinidiaceae), as a bone marrow cell proliferation-promoting compound against the hematotoxicity of 5-fluorouracil (5-FU) in mice. Intraperitoneally injected (+)-catechin (1 and 10 mg/kg per day) accelerated the recovery of the number of white blood cells (WBC) and platelets (PLT) but did not affect the number of circulating red blood cells (RBC). (+)-Catechin also augmented the number of myelocytes and splenocytes. Dual color flow cytometric analysis revealed that (+)-catechin reversed the reduction of the population of leukocytes (CD11b+ monocytes, Gr-1+ granulocytes and CD3+ T and CD45RA+ B lymphocytes) in whole blood, spleen and bone marrow caused by 5-FU. (+)-Catechin (1 and 10 mg/kg per day) showed remarkable recovery of Gr-1+ cells in all three types of tissues and of CD11b+ cells in the bone marrow cells. These findings suggest that (+)-catechin selectively enhances the recovery of the population of granulocytes reduced by 5-FU in mice.