Exposure to ambient air fine particulate matter prevents VEGF-induced mobilization of endothelial progenitor cells from the bone marrow

Background: Exposure to ambient fine particulate matter air pollution (PM_2.5; < 2.5 µm in aerodynamic diameter) induces endothelial dysfunction and increases the risk for cardiovascular disease. Endothelial progenitor cells (EPCs) contribute to postnatal endothelial repair and regeneration. In humans and mice, EPC levels are decreased upon exposure to elevated levels of PM_2.5.Objective: We examined the mechanism by which PM_2.5 exposure suppresses circulating levels of EPCs.Methods: Mice were exposed to HEPA-filtered air or concentrated ambient fine particulate matter (CAP, 30–100 µg/m³) from downtown Louisville (Kentucky) air, and progenitor cells from peripheral blood or bone marrow were analyzed by flow cytometry or by culture ex vivo.Results: Exposure of the mice to CAP (6 hr/day) for 4–30 days progressively decreased circulating levels of EPCs positive for both Flk-1 and Sca-1 (Flk-1⁺/Sca-1⁺) without affecting stem cells positive for Sca-1 alone (Sca-1⁺). After 9 days of exposure, a 7-day exposure-free period led to complete recovery of the circulating levels of Flk-1⁺/Sca-1⁺ cells. CAP exposure decreased circulating levels of EPCs independent of apoptosis while simultaneously increasing Flk-1⁺/Sca-1⁺ cells in the bone marrow. We observed no change in tissue deposition of these cells. CAP exposure suppressed vascular endothelial growth factor (VEGF)-induced Akt and endothelial nitric oxide synthase (eNOS) phosphorylation in the aorta, and it prevented VEGF/AMD3100-induced mobilization of Flk-1⁺/Sca-1⁺ cells into the peripheral blood. Treatment with stem cell factor/AMD3100 led to a greater increase in circulating Flk-1⁺/Sca-1⁺ cells in CAP-exposed mice than in mice breathing filtered air.Conclusion: Exposure to PM_2.5 increases EPC levels in the bone marrow by preventing their mobilization to the peripheral blood via inhibition of signaling events triggered by VEGF-receptor stimulation that are upstream of c-kit activation. Suppression of EPC mobilization by PM_2.5 could induce deficits in vascular repair or regeneration.     

Radioprotector WR-2721 and mitigating peptidoglycan synergistically promote mouse survival through the amelioration of intestinal and bone marrow damage

The identification of an agent effective for the treatment of intestinal and bone marrow injury following radiation exposure remains a major issue in radiological medicine. In this study, we evaluated the therapeutic impact of single agent or combination treatments with 2-(3-aminopropylamino) ethylsulphanyl phosphonic acid (WR-2721) and peptidoglycan (PGN, a toll-like receptor 2 (TLR-2) agonist) on radiation-induced injury of the intestine and bone marrow in lethally irradiated male C57BL/6 mice. A dose of 3 mg of WR-2721 per mouse (167 mg/kg, intraperitoneally) was given 30 min before irradiation, and 30 μg of PGN per mouse (1.7 mg/kg) was injected intraperitoneally 24 h after 10 Gy irradiation. Bone marrow cluster of differentiation (CD)45⁺ and CD34⁺ markers of multiple haematopoietic lineages, number of granulocyte–erythroid–macrophage–megakaryocyte (GEMM) progenitor colonies, bone marrow histopathology, leucine-rich repeat-containing G-protein-coupled receptor 5 (Lgr5) expression in the intestines, xylose absorption and intestinal histopathology were all assessed at various time-points after irradiation. Furthermore, nuclear factor kappa B (NF-κB) p65 protein in the ileum was stained by immunofluorescent labelling. PGN-treated irradiated mice showed an increase in CD45⁺CD34⁺ cells compared with untreated mice 1.25 days after 10 Gy ionizing radiation (IR) (P < 0.05). Furthermore, combined PGN and WR-2721 treatment had an obviously synergistic radio-protective effect in nucleated cells in the bone marrow, including GEMM progenitors and CD45⁺CD34⁺ cells 4 days after 10 Gy IR. Single agent PGN or WR-2721 treatment after 10 Gy IR clearly increased Lgr5-positive pit cells (P < 0.05) and xylose absorption (P < 0.05). However only PGN and WR-2721 combination treatment markedly increased villus height (P < 0.05), number of crypts (P < 0.05) and whole-body weights after 10 Gy whole-body irradiation (WBI). The NF-κB p65 subunit was translocated to the nucleus, and phosphate-IκBα (Ser32/Ser36) was detected after stimulation with either PGN or WR-2721, which indicates that these two agents act synergistically through the activation of the NF-κB pathway. Administration of PGN in combination with WR-2721 was demonstrated to have a synergistic effect on the increase in haematopoietic cells and intestinal reconstitution, as well as improved survival in lethally irradiated mice, but resulted in some degree of an immune disorder.     

Cranial irradiation induces bone marrow-derived microglia in adult mouse brain tissue

Postnatal hematopoietic progenitor cells do not contribute to microglial homeostasis in adult mice under normal conditions. However, previous studies using whole-body irradiation and bone marrow (BM) transplantation models have shown that adult BM cells migrate into the brain tissue and differentiate into microglia (BM-derived microglia; BMDM). Here, we investigated whether cranial irradiation alone was sufficient to induce the generation of BMDM in the adult mouse brain. Transgenic mice that express green fluorescent protein (GFP) under the control of a murine stem cell virus (MSCV) promoter (MSCV-GFP mice) were used. MSCV-GFP mice express GFP in BM cells but not in the resident microglia in the brain. Therefore, these mice allowed us to detect BM-derived cells in the brain without BM reconstitution. MSCV–GFP mice, aged 8–12 weeks, received 13.0 Gy irradiation only to the cranium, and BM-derived cells in the brain were quantified at 3 and 8 weeks after irradiation. No BM-derived cells were detected in control non-irradiated MSCV-GFP mouse brains, but numerous GFP-labeled BM-derived cells were present in the brain stem, basal ganglia and cerebral cortex of the irradiated MSCV-GFP mice. These BM-derived cells were positive for Iba1, a marker for microglia, indicating that GFP-positive BM-derived cells were microglial in nature. The population of BMDM was significantly greater at 8 weeks post-irradiation than at 3 weeks post-irradiation in all brain regions examined. Our results clearly show that cranial irradiation alone is sufficient to induce the generation of BMDM in the adult mouse.     

Inhibiting TGFβ1 has a protective effect on mouse bone marrow suppression following ionizing radiation exposure in vitro

Ionizing radiation (IR) causes not only acute tissue damage but also residual bone marrow (BM) suppression. The induction of residual BM injury is primarily attributable to the induction of reactive oxygen species (ROS) pressure in hematopoietic cells. In this study, we examined if SB431542, a transforming growth factor β1 (TGFβ1) inhibitor, can mitigate IR-induced BM suppression in vitro. Our results showed that treatment with SB431542 protected mice bone marrow mononuclear cells (BMMNCs), hematopoietic progenitor cells (HPCs) and hematopoietic stem cells (HSCs) from IR-induced suppression using cell viability assays, clonogenic assays and competitive repopulation assays. Moreover, expression of gene-related ROS production in hematopoietic cells was analyzed. The expression of NOX1, NOX2 and NOX4 was increased in irradiated BMMNCs, and that of NOX2 and NOX4 was reduced by SB431542 treatment. Therefore, the results from this study suggest that SB431542, a TGFβ1 inhibitor, alleviates IR-induced BM suppression at least in part via inhibiting IR-induced NOX2 and NOX4 expression.     

Characteristics of human CD34+ cells exposed to ionizing radiation under cytokine-free conditions

To clarify the mechanisms underlying radiation-induced hematopoietic stem cell death, we investigated the effects of excessive ionizing radiation on the clonogenic potential of CD34⁺ cells obtained from human umbilical cord blood under cytokine-free conditions. The CD34⁺ cells were X-ray–irradiated (up to 2 Gy) and were cultured for 0–48 h under cytokine-free conditions. At various time-points, the CD34⁺ cells were investigated for survival, clonogenic potential and the generation of mitochondrial superoxide. At 12 h after X-ray irradiation, the number of viable cells had decreased to ∼70–80% compared with the 0-h non-irradiated control, whereas the clonogenic potential in the X-ray–irradiated cells had decreased to ∼50%–60% compared with the 0-h non-irradiated control. Furthermore, significant generation of mitochondrial superoxide was observed at 6 h, and reached a maximum value between 12 and 24 h after X-ray irradiation. However, no significant differences were observed between non-irradiated and X-ray–irradiated cells in terms of the generation of reactive oxygen species or in the intracellular mitochondrial contents. In addition, a cDNA microarray analysis showed that the majority of the altered genes in the CD34⁺ cells at 6 h after X-ray irradiation were apoptosis-related genes. These results suggest the possibility that the elimination of the clonogenic potentials of CD34⁺ cells involves the generation of mitochondrial superoxide induced by ionizing radiation.     

Involvement of placental/umbilical cord blood acid–base status and gas values on the radiosensitivity of human fetal/neonatal hematopoietic stem/progenitor cells

Arterial cord blood (CB) acid–base status and gas values, such as pH, PCO₂, PO₂, HCO₃⁻and base excess, provide useful information on the fetal and neonatal condition. However, it remains unknown whether these values affect the radiosensitivity of fetal/neonatal hematopoiesis. The present study evaluated the relationship between arterial CB acid–base status, gas values, and the radiosensitivity of CB hematopoietic stem/progenitor cells (HSPCs). A total of 25 CB units were collected. The arterial CB acid–base status and gas values were measured within 30 min of delivery. The CD34⁺HSPCs obtained from CB were exposed to 2 Gy X-irradiation, and then assayed for colony-forming unit-granulocyte-macrophage, burst-forming unit-erythroid (BFU-E), and colony-forming unit-granulocyte erythroid, macrophage and megakaryocyte cells. Acid–base status and gas values for PCO₂and HCO₃⁻showed a statistically significant negative correlation with the surviving fraction of BFU-E. In addition, a significant positive correlation was observed between gestational age and PCO₂. Moreover, the surviving fraction of BFU-E showed a significant negative correlation with gestational age. Thus, HSPCs obtained from CB with high PCO₂/HCO₃⁻levels were sensitive to X-irradiation, which suggests that the status of arterial PCO₂/HCO₃⁻influences the radiosensitivity of fetal/neonatal hematopoiesis, especially erythropoiesis.     

Subcutaneous administration of rhIGF-I post irradiation exposure enhances hematopoietic recovery and survival in BALB/c mice

It is unclear how to effectively mitigate against irradiation injury. In this study, we studied the capacity of recombinant human insulin-like growth factor-I (rhIGF-I) on hematologic recovery in irradiated BALB/c mice and its possible mechanism. BALB/c mice were injected with rhIGF-I subcutaneously at a dose of 100 μg/kg twice daily for 7 days after total body irradiation. Compared with a saline control group, treatment with rhIGF-I significantly improved the survival of mice after lethal irradiation (7.5 Gy). It was found that treatment with rhIGF-I not only could increase the frequency of Sca-1⁺ cells in bone marrow harvested at Day 14 after irradiation, but also it could decrease the apoptosis of mononuclear cells induced by irradiation as measured by flow cytometry, suggesting that rhIGF-I may mediate its effects primarily through promoting hematopoietic stem cell/progenitor survival and protecting mononuclear cells from apoptosis after irradiation exposure. Moreover, we have found that rhIGF-I might facilitate thrombopoiesis in an indirect way. Our data demonstrated that rhIGF-I could promote overall hematopoietic recovery after ionizing radiation and reduce the mortality when administered immediately post lethal irradiation exposure.     

Severe acute radiation syndrome: treatment of a lethally 60Co-source irradiated accident victim in China with HLA-mismatched peripheral blood stem cell transplantation and mesenchymal stem cells

This is a case report of a 32-year-old man exposed to a total body dose of 14.5 Gy γ-radiation in a lethal ⁶⁰Co-source irradiation accident in 2008 in China. Frequent nausea, vomiting and marked neutropenia and lymphopenia were observed from 30 min to 45 h after exposure. HLA-mismatched peripheral blood stem cell transplantation combined with infusion of mesenchymal stem cells was used at Day 7. Rapid hematopoietic recovery, stable donor engraftment and healing of radioactive skin ulceration were achieved during Days 18–36. The patient finally developed intestinal obstruction and died of multi-organ failure on Day 62, although intestinal obstruction was successfully released by emergency bowel resection.     

Chronic consumption of a moderately low protein diet does not alter hematopoietic processes in young adult mice

The current studies examined whether hematopoiesis in the bone marrow and T-cell development in the thymus were attenuated in young adult A/J mice fed a moderately low protein diet (MPD, 50 g protein/kg) for 15 wk compared with mice fed a control protein diet (CPD, 180 g protein/kg). Flow cytometric analyses using antibodies against CD31 and Ly-6C as well as CD4 and CD8 were performed to identify stem, mixed progenitor, erythroid, lymphoid, granuloid and monocytic compartments in the bone marrow and four thymocyte subsets, respectively. Chronic restriction of young adult mice to MPD neither decreased the cellularity nor altered the distribution of subpopulations in either primary tissue. Subsequently, a new set of mice were provided with CPD and a low protein diet (LPD, 25 g protein/kg). After 5 wk, body and thymus weights in LPD group were reduced 26 and 30%, respectively, which was accompanied by a 505% increase in serum corticosterone. Surprisingly, LPD did not alter the number or distribution of cells in the bone marrow and the percentages of thymocyte subsets, supporting the findings from the MPD group. We conclude that chronic consumption of a marginal protein diet by young adult mice does not disrupt hematopoietic processes.     

Krill Protein Hydrolysate Provides High Absorption Rate for All Essential Amino Acids—A Randomized Control Cross-Over Trial

Background: adequate protein intake is essential to humans and, since the global demand for protein-containing foods is increasing, identifying new high-quality protein sources is needed. In this study, we investigated the acute postprandial bioavailability of amino acids (AAs) from a krill protein hydrolysate compared to a soy and a whey protein isolate. Methods: the study was a randomized, placebo-controlled crossover trial including ten healthy young males. On four non-consecutive days, volunteers consumed water or one of three protein-matched supplements: whey protein isolate, soy protein isolate or krill protein hydrolysate. Blood samples were collected prior to and until 180 min after consumption. Serum postprandial AA concentrations were determined using ¹H NMR spectroscopy. Hunger and satiety were assessed using visual analogue scales (VAS). Results: whey and krill resulted in significantly higher AA concentrations compared to soy between 20–60 min and 20–40 min after consumption, respectively. Area under the curve (AUC) analyses revealed that whey resulted in the highest postprandial serum concentrations of essential AAs (EAAs) and branched chain AAs (BCAAs), followed by krill and soy, respectively. Conclusions: krill protein hydrolysate increases postprandial serum EAA and BCAA concentrations in a superior manner to soy protein isolate and thus might represent a promising future protein source in human nutrition.     

造血干细胞移植治疗骨髓型急性放射病的研究进展

核武器爆炸或核物质泄漏导致的核事故,短时间内会造成急性放射病.人体接受剂量＞0.7Gy辐射可导致骨髓持久抑制即急性放射病,引起全血细胞减少、出血、感染等损伤.大量研究显示,造血干细胞移植是治疗骨髓型急性放射性疾病的主要手段.造血干细胞可以修复骨髓造血损伤,改善造血微环境,促进造血重建.在使用造血干细胞移植术前选择供者、...     

Immunostimulatory Effects of Live Lactobacillus sakei K040706 on the CYP-Induced Immunosuppression Mouse Model

Our previous studies have shown that heat-killed Lactobacillus sakei K040706 exerts immunostimulatory and anti-inflammatory activities in macrophages, cyclophosphamide (CYP)-treated mice, and dextran sulfate sodium–induced colitis mice. However, the immunostimulatory effects of live Lactobacillus sakei K040706 (live K040706) against CYP-induced immunosuppression and its underlying molecular mechanisms remain unknown. Therefore, we investigated the immunostimulatory effects of live K040706 (10⁸ or 10⁹ colony forming unit (CFU)/day, p.o.) in CYP-induced immunosuppressed mice. Oral administration of live K040706 prevented the CYP-induced decreases in body weight, thymus index, natural killer (NK) cell activity, T and B cell proliferation, and cytokine (interferon (IFN)-γ, interleukin (IL)-2, and IL-12) production. The administration of live K040706 also exerted positive effects on the gut microbiota of CYP-induced mice, resulting in a microbiota composition similar to that of normal mice. Moreover, live K040706 significantly enhanced IL-6 and granulocyte-macrophage colony-stimulating factor (GM-CSF) production in the splenocytes and Peyer’s patch (PP) cells of mice and increased bone marrow (BM) cell proliferation. Taken together, our data indicate that live K040706 may effectively accelerate recovery from CYP-induced immunosuppression, leading to activation of the immune system. Therefore, live K040706 may serve as a potential immunomodulatory agent against immunosuppression.     

骨髓间充质干细胞支持脐血造血干／祖细胞体外扩增的研究

目的体外分离培养人新鲜脐血（UCB）造血干细胞（HSC），利用骨髓间充质干细胞作为滋养层联合细胞因子组合以扩增脐血造血干／祖细胞。方法采用Ficoll淋巴细胞分离液密度梯度离心法分离UCBHSC，加入骨髓间充质干细胞和细胞因子，检测脐血造血干／祖细胞总有核细胞（NC）总数和CD34^＋细胞数。结果有核细胞总数扩增（75．2±15．0）倍，CD34^＋细胞数扩增（18．7±12．3）倍。结论体外HSC培养，加入骨髓间充质干细胞和细胞因子对造血干／祖细胞增殖有明显的作用。     

骨髓间充质干细胞促进异基因骨髓移植后造血恢复

目的探讨骨髓间充质干细胞(BMMSC)对异基因骨髓移植小鼠造血功能恢复的影响。方法将供鼠C57BL/6(H-2b)的骨髓细胞和体外培养的BMMSC联合输给致死量照射的受鼠BalB/c(H-2d)。在移植后第1、7、14天检测受鼠外周血红细胞(RBC)、白细胞(WBC)、血小板(BPC);移植后第7、14天检测受鼠骨髓中的脾集落形成单位(CFU-S)。结果联合移植组小鼠第7、14天的外周血红细胞、白细胞、血小板、CFU-S数均显著高于单纯移植组(P<0.01)。结论BMMSC能促进异基因骨髓移植后造血功能重建。     

Regeneration of the immune system after bone marrow transplantation

After haematopoietic stem cell transplantation, reconstitution of bone marrow consists of two distinct phenomena, numerical recovery of bone marrow cellular elements on the one hand and functional recovery of cellular interactions on the other. Immune reactivity during the first month postgrafting is extremely low. Cytotoxic and phagocytic functions usually recover by day 100, while more specialized and cooperative functions of T and B cells remain impaired up to one year or more postgrafting. Regeneration of total CD4+ T cell number in adult (and especially in elderly) transplant recipients is severely limited and occurs largely by peripheral expansion of mature CD4+ T cells. While restoration of total CD8+ T cell number is commonly seen in adults, potentially important alterations in the subset composition of CD8+ populations remain. Contracted T cell repertoires for CD4+ and CD8+ T cells are consistently found in adults after T cell regeneration. This suggests that thymic function is frequently limiting in adults and that thymic-independent pathways are insufficient for restoring host immunocompetence. Although there are similarities in immune reconstitution after alllo- and autologous haematopoietic stem cell transplantations, allogeneic transplantation involves graft versus host disease and the use of immunosuppressive therapy to control it, both of which further interfere in the early developmental stages of immune reconstitution.     

Radioprotective Effect of Whey Hydrolysate Peptides against γ-Radiation-Induced Oxidative Stress in BALB/c Mice

Radiation therapy is widely used in the treatment of tumor diseases, but it can also cause serious damage to the body, so it is necessary to find effective nutritional supplements. The main purpose of this study is to evaluate the protective effect of whey hydrolysate peptides (WHPs) against ⁶⁰Coγ radiation damage in mice and explore the mechanism. BALB/c mice were given WHPs by oral gavage administration for 14 days. Then, some mice underwent a 30-day survival test after 8 Gy radiation, and other mice received 3.5 Gy radiation to analyze the changes in body weight, hematology and bone marrow DNA after three and 14 days. In addition, through further analysis of the level of oxidative stress and intestinal barrier function, the possible mechanism of the radioprotective effect of WHPs was explored. The study found WHPs can prolong survival time, restore body weight, and increase the number of peripheral blood white blood cells and bone marrow DNA content in irradiated mice. In addition, WHPs can significantly improve the antioxidant capacity, inhibit pro-inflammatory cytokines and protect the intestinal barrier. These results indicate that WHPs have a certain radioprotective effect in mice, and the main mechanism is related to reducing oxidative damage.     

Malnutrition suppresses cell cycle progression of hematopoietic progenitor cells in mice via cyclin D1 down-regulation

ObjectiveProtein malnutrition (PM) often is associated with changes in bone marrow (BM) microenvironment leading to an impaired hematopoiesis; however, the mechanism involved is poorly understood. The aim of this study was to compare the cell cycle progression of hematopoietic stem cells (HSC) and hematopoietic progenitor cells (HPC) and evaluate the cell cycle signaling in malnourished mice to assess the mechanism of cell cycle arrest.MethodsC57Bl/6J mice were randomly assigned in control and malnourished groups receiving normoproteic and hypoproteic diets (12% and 2% protein, respectively) over a 5-wk period. Nutritional and hematologic parameters were assessed and BM immunophenotypic analysis was performed. Cell cycle of HPC (Lin^–) and HSC (Lin^–Sca-1⁺c-Kit⁺) were evaluated after 6 h of in vivo 5-bromo-2'-deoxyuridine (BrDU) incorporation. Cell cycle regulatory protein expression of HPC was assessed by Western blot.ResultsMalnourished mice showed lower levels of serum protein, albumin, glucose, insulin-like growth factor-1, insulin, and higher levels of serum corticosterone. PM also caused a reduction of BM myeloid compartment resulting in anemia and leukopenia. After 6 h of BrDU incorporation, malnourished mice showed G0-G1 arrest of HPC without changes of HSC proliferation kinetics. HPC of malnourished mice showed reduced expression of proteins that induce cell cycle (cyclin D1, cyclin E, pRb, PCNA, Cdc25a, Cdk2, and Cdk4) and increased expression of inhibitory proteins (p21 and p27) with no significant difference in p53 expression.ConclusionPM suppressed cell cycle progression mainly of HPC. This occurred via cyclin D1 down-regulation and p21/p27 overexpression attesting that BM microenvironment commitment observed in PM is affecting cell interactions compromising cell proliferation.     

Hematopoietic effect of deer antler extract fermented by Bacillus subtilis on murine marrow cells

BACKGROUND/OBJECTIVES

We examined the chemical composition and the effect of fermented deer antler on hematopoietic factors in bone marrow cells.

MATERIALS/METHODS

For the preparation of fermented deer antler extract (FAB), fermentation was carried out using Bacillus subtilis at 30℃ for 7 days. The hematopoietic effect of FAB was investigated hematopoietic factors in marrow cells.

RESULTS

The contents of total sugar, sulfated glycosaminoglycans, and uronic acid and the dry weight gradually increased with fermentation time. The sialic acid content (from 0.14 mg/mL to 0.54 mg/mL) was the highest on the 4th day of fermentation after which it decreased. The proliferating activity of bone marrow cells increased with fermentation times. The levels of various hematopoietic growth factors were determined to verify the beneficial effect of deer antler extract fermented by B. subtilis on hematopoiesis. FAB increased the number of stem cell factors and granulocyte colony-stimulating factor in bone marrow cells. In addition, FAB augmented the burst-forming unit erythroid and total colonies in splenocyte-conditioned medium compared with non-fermented antler extract (NFA). However, FAB did not affect the mRNA levels of erythropoietin, an important factor for erythropoiesis.

CONCLUSIONS

FAB, like NFA, did not directly affect hematopoiesis, but contributed to hematopoiesis by stimulating the production of hematopoietic factors.     

Plasma Free Amino Acid Responses to Intraduodenal Whey Protein,and Relationships with Insulin,Glucagon-Like Peptide-1 and Energy Intake in Lean Healthy Men

This study determined the effects of increasing loads of intraduodenal (ID) dairy protein on plasma amino acid (AA) concentrations, and their relationships with serum insulin, plasma glucagon-like peptide-1 (GLP-1) and energy intake. Sixteen healthy men had concentrations of AAs, GLP-1 and insulin measured in response to 60-min ID infusions of hydrolysed whey protein administered, in double-blinded and randomised order, at 2.1 (P2.1), 6.3 (P6.3) or 12.5 (P12.5) kJ/min (encompassing the range of nutrient emptying from the stomach), or saline control (C). Energy intake was quantified immediately afterwards. Compared with C, the concentrations of 19/20 AAs, the exception being cysteine, were increased, and this was dependent on the protein load. The relationship between AA concentrations in the infusions and the area under the curve from 0 to 60 min (AUC_{0–60 min}) of each AA profile was strong for essential AAs (R² range, 0.61–0.67), but more variable for non-essential (0.02–0.54) and conditional (0.006–0.64) AAs. The AUC_{0–60 min} for each AA was correlated directly with the AUC_{0–60 min} of insulin (R² range 0.3–0.6), GLP-1 (0.2–0.6) and energy intake (0.09–0.3) (p < 0.05, for all), with the strongest correlations being for branched-chain AAs, lysine, methionine and tyrosine. These findings indicate that ID whey protein infused at loads encompassing the normal range of gastric emptying increases plasma concentrations of 19/20 AAs in a load-dependent manner, and provide novel information on the close relationships between the essential AAs, leucine, valine, isoleucine, lysine, methionine, and the conditionally-essential AA, tyrosine, with energy intake, insulin and GLP-1.     

Radioprotective effects of Sipunculus nudus L. polysaccharide combined with WR-2721, rhIL-11 and rhG-CSF on radiation-injured mice

This study investigated the radioprotective effect of Sipunculus nudus L. polysaccharide (SNP) in combination with WR-2721, rhIL-11 and rhG-CSF on irradiated mice. A total of 70 Imprinting Control Region (ICR) mice were divided into seven groups: the control group, the model group and five administration groups. All groups, except the control group, were exposed to a 5 Gy ⁶⁰Co γ-ray beam. Blood parameters [including white blood cell (WBC), red blood cell (RBC) and platelet counts and hemoglobin level] were assessed three days before irradiation, and the on the 3rd, 7th and 14th days after irradiation. Spleen, thymus and testicular indices, DNA contents of bone marrow cells, bone marrow nucleated cells, sperm counts, superoxide dismutase (SOD), malondialdehyde (MDA), testosterone and estradiol levels in the serum were assessed on the 14th day after irradiation. The combined administration of SNP, WR-2721, rhIL-11 and rhG-CSF exerted synergistic recovery effects on peripheral blood WBC, RBC and platelet counts and hemoglobin levels in irradiated mice, and synergistic promotion effects on spleen, thymus, testicle, bone marrow nucleated cells and sperm counts in irradiated mice. The synergistic administration increased the serum SOD activities and serum testosterone content of irradiated mice, but synergy decreased the content of serum MDA and estradiol in irradiated mice. These results suggest that the combined administration of SNP, WR-2721, rhIL-11 and rhG-CSF should increase the efficacy of these drugs for acute radiation sickness, protect immunity, hematopoiesis and the reproductive organs of irradiated-damaged mice, and improve oxidation resistance in the body.