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Micro-concentration Lipopolysaccharide as a Novel Stimulator of Megakaryocytopoiesis that Synergizes with IL-6 for Platelet Production.

Wu D, Xie J, Wang X, Zou B, Yu Y, Jing T, Zhang S, Zhang Q - Sci Rep (2015)

Bottom Line: We found that serial doses of micro-concentration LPS significantly increased the platelet count in mice treated with kanamycin, along with increased expression of IL-6 compared with IL-3 and TPO in megakaryocytes obtained from the mouse bone morrow following LPS administration.Furthermore, LPS at lower levels ranging plus IL-6 effectively stimulated CFU-MK formation and increased CD41 expression and megakaryocyte polyploidization.Notably, the optimal LPS concentration in combination with IL-6 might be a novel stimulator of TLR4 and IL-6R expression in Dami cell lines, which initially occurs through TLR4-IL-6R crosstalk and then involves the activation of NF-κB and phosphorylation of p38 MAPK.

View Article: PubMed Central - PubMed

Affiliation: State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, China.

ABSTRACT
Lipopolysaccharide (LPS) induces platelet activation and enhances platelet sensitivity to aggregation, which might alter platelet counts. We found that serial doses of micro-concentration LPS significantly increased the platelet count in mice treated with kanamycin, along with increased expression of IL-6 compared with IL-3 and TPO in megakaryocytes obtained from the mouse bone morrow following LPS administration. Furthermore, LPS at lower levels ranging plus IL-6 effectively stimulated CFU-MK formation and increased CD41 expression and megakaryocyte polyploidization. Meanwhile, there was a sustained rise in the percentage of reticulated platelets in the whole blood in response to low-dosage LPS combined with IL-6. In vivo experiments also demonstrated that the administration of LPS combined with IL-6 substantially enhanced the number of circulating platelets in normal and thrombocytopenic mice. Notably, the optimal LPS concentration in combination with IL-6 might be a novel stimulator of TLR4 and IL-6R expression in Dami cell lines, which initially occurs through TLR4-IL-6R crosstalk and then involves the activation of NF-κB and phosphorylation of p38 MAPK. These data suggest a new paradigm for the regulation of megakaryocytopoiesis and platelet production via a synergistic effect of LPS and IL-6, which has the potential to be used for the design of new therapies.

No MeSH data available.


Related in: MedlinePlus

Effect of LPS or IL-6 alone or in combination on platelet counts.(A) Normal mice received IL-6 or IL-6 plus LPS at the indicated dosage once per day for 7 consecutive days. The control mice received PBS-BSA only. Platelets were counted at the indicated time points. Each dose resulted in significant increases in the platelet counts relative to the control (*P < 0.05; **P < 0.01, and ***P < 0.001). (B) Platelet counts in 5-FU-induced myelosuppressed mice. One hour after 5-FU injection at a dose of 150 mg/kg, the mice were intravenously given PBS-BSA (open circles), 8.0 μg/kg/day LPS (filled squares), 100 μg/kg/day IL-6 (open squares), or a combination of LPS and IL-6 (filled triangles). Mice untreated with 5-FU but still given PBS-BSA injections were used to gauge the baseline platelet levels (open triangles). Platelets were counted at the indicated time points.
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f8: Effect of LPS or IL-6 alone or in combination on platelet counts.(A) Normal mice received IL-6 or IL-6 plus LPS at the indicated dosage once per day for 7 consecutive days. The control mice received PBS-BSA only. Platelets were counted at the indicated time points. Each dose resulted in significant increases in the platelet counts relative to the control (*P < 0.05; **P < 0.01, and ***P < 0.001). (B) Platelet counts in 5-FU-induced myelosuppressed mice. One hour after 5-FU injection at a dose of 150 mg/kg, the mice were intravenously given PBS-BSA (open circles), 8.0 μg/kg/day LPS (filled squares), 100 μg/kg/day IL-6 (open squares), or a combination of LPS and IL-6 (filled triangles). Mice untreated with 5-FU but still given PBS-BSA injections were used to gauge the baseline platelet levels (open triangles). Platelets were counted at the indicated time points.

Mentions: To confirm the hypothesis that recombinant LPS with IL-6 can synergistically stimulate platelet production in vivo, we evaluated the platelet numbers in normal mice after LPS was administered. Figure 8A shows that LPS significantly increased the platelet counts between 0.8 and 8.0 μg/kg in a dose-dependent manner in the presence of 100.0 μg/kg IL-6. At 7 d, the platelet counts increased by 57.3%, 139.5%, and 104.7% with 100.0 μg/kg IL-6 alone and with 0.8 and 8.0 μg/kg LPS, respectively (n = 10, P < 0.01). At 10 d, the platelet counts increased by 51.2%, 119.3%, and 92.3% with 100.0 μg/kg IL-6 alone and with 0.8 and 8.0 μg/kg LPS, respectively (n = 10, P < 0.05). At each time point, the platelet counts observed in IL-6-treated mice were lower than in those treated with IL-6 and LPS (0.8 and 8.0 μg/kg), except in the presence of high LPS doses (80.0 μg/kg). The platelet numbers gradually declined at 16 d and returned to pre-injection levels. A second separate experiment was performed to evaluate the recovery of platelets after 5-FU-induced thrombocytopenia. As shown in Fig. 8B, with the exception of the control group, platelet nadirs were observed on days 4 and 7, and the depths of the nadirs were not significantly different among all groups after 5-FU injection. However, the recovery of platelet counts was faster after 7 d; the peak platelet levels occurred on day 10. The elevation of platelet levels in mice injected with LPS plus IL-6 was much higher than that in PBS-BSA-injected mice (P < 0.05). Mice treated with 8.0 μg/kg LPS plus 100.0 μg/kg IL-6 had a more marked response at day 10; the platelet levels in these mice were approximately 3123 ± 126 × 109/L, compared with 1941 ± 131 × 109/L for LPS treatment alone and 2463 ± 167 × 109/L for IL-6 treatment alone (n = 10, P < 0.05). Recovery was not more pronounced in mice treated with IL-6 alone versus LPS alone (P > 0.05). After day 10, the platelet levels began to decline in all groups but did not return to the baseline values until 19 d. Overall, the platelet counts of two treatments and 5-FU group mice in different times were significantly different (ANOVA, P < 0.01, 0.05 and 0.01 for LPS plus IL-6, IL-6 and 5-FU respectively), while the control group in which time-of-day changes were not significant (ANOVA, P > 0.05). In addition, significant difference of platelet counts between different treatments was revealed by MNOVA (P < 0.01), showing as the platelet counts of mice treated by LPS plus IL-6 and IL-6 significantly higher than those of 5-FU treatment and control group.


Micro-concentration Lipopolysaccharide as a Novel Stimulator of Megakaryocytopoiesis that Synergizes with IL-6 for Platelet Production.

Wu D, Xie J, Wang X, Zou B, Yu Y, Jing T, Zhang S, Zhang Q - Sci Rep (2015)

Effect of LPS or IL-6 alone or in combination on platelet counts.(A) Normal mice received IL-6 or IL-6 plus LPS at the indicated dosage once per day for 7 consecutive days. The control mice received PBS-BSA only. Platelets were counted at the indicated time points. Each dose resulted in significant increases in the platelet counts relative to the control (*P < 0.05; **P < 0.01, and ***P < 0.001). (B) Platelet counts in 5-FU-induced myelosuppressed mice. One hour after 5-FU injection at a dose of 150 mg/kg, the mice were intravenously given PBS-BSA (open circles), 8.0 μg/kg/day LPS (filled squares), 100 μg/kg/day IL-6 (open squares), or a combination of LPS and IL-6 (filled triangles). Mice untreated with 5-FU but still given PBS-BSA injections were used to gauge the baseline platelet levels (open triangles). Platelets were counted at the indicated time points.
© Copyright Policy - open-access
Related In: Results  -  Collection

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getmorefigures.php?uid=PMC4557119&req=5

f8: Effect of LPS or IL-6 alone or in combination on platelet counts.(A) Normal mice received IL-6 or IL-6 plus LPS at the indicated dosage once per day for 7 consecutive days. The control mice received PBS-BSA only. Platelets were counted at the indicated time points. Each dose resulted in significant increases in the platelet counts relative to the control (*P < 0.05; **P < 0.01, and ***P < 0.001). (B) Platelet counts in 5-FU-induced myelosuppressed mice. One hour after 5-FU injection at a dose of 150 mg/kg, the mice were intravenously given PBS-BSA (open circles), 8.0 μg/kg/day LPS (filled squares), 100 μg/kg/day IL-6 (open squares), or a combination of LPS and IL-6 (filled triangles). Mice untreated with 5-FU but still given PBS-BSA injections were used to gauge the baseline platelet levels (open triangles). Platelets were counted at the indicated time points.
Mentions: To confirm the hypothesis that recombinant LPS with IL-6 can synergistically stimulate platelet production in vivo, we evaluated the platelet numbers in normal mice after LPS was administered. Figure 8A shows that LPS significantly increased the platelet counts between 0.8 and 8.0 μg/kg in a dose-dependent manner in the presence of 100.0 μg/kg IL-6. At 7 d, the platelet counts increased by 57.3%, 139.5%, and 104.7% with 100.0 μg/kg IL-6 alone and with 0.8 and 8.0 μg/kg LPS, respectively (n = 10, P < 0.01). At 10 d, the platelet counts increased by 51.2%, 119.3%, and 92.3% with 100.0 μg/kg IL-6 alone and with 0.8 and 8.0 μg/kg LPS, respectively (n = 10, P < 0.05). At each time point, the platelet counts observed in IL-6-treated mice were lower than in those treated with IL-6 and LPS (0.8 and 8.0 μg/kg), except in the presence of high LPS doses (80.0 μg/kg). The platelet numbers gradually declined at 16 d and returned to pre-injection levels. A second separate experiment was performed to evaluate the recovery of platelets after 5-FU-induced thrombocytopenia. As shown in Fig. 8B, with the exception of the control group, platelet nadirs were observed on days 4 and 7, and the depths of the nadirs were not significantly different among all groups after 5-FU injection. However, the recovery of platelet counts was faster after 7 d; the peak platelet levels occurred on day 10. The elevation of platelet levels in mice injected with LPS plus IL-6 was much higher than that in PBS-BSA-injected mice (P < 0.05). Mice treated with 8.0 μg/kg LPS plus 100.0 μg/kg IL-6 had a more marked response at day 10; the platelet levels in these mice were approximately 3123 ± 126 × 109/L, compared with 1941 ± 131 × 109/L for LPS treatment alone and 2463 ± 167 × 109/L for IL-6 treatment alone (n = 10, P < 0.05). Recovery was not more pronounced in mice treated with IL-6 alone versus LPS alone (P > 0.05). After day 10, the platelet levels began to decline in all groups but did not return to the baseline values until 19 d. Overall, the platelet counts of two treatments and 5-FU group mice in different times were significantly different (ANOVA, P < 0.01, 0.05 and 0.01 for LPS plus IL-6, IL-6 and 5-FU respectively), while the control group in which time-of-day changes were not significant (ANOVA, P > 0.05). In addition, significant difference of platelet counts between different treatments was revealed by MNOVA (P < 0.01), showing as the platelet counts of mice treated by LPS plus IL-6 and IL-6 significantly higher than those of 5-FU treatment and control group.

Bottom Line: We found that serial doses of micro-concentration LPS significantly increased the platelet count in mice treated with kanamycin, along with increased expression of IL-6 compared with IL-3 and TPO in megakaryocytes obtained from the mouse bone morrow following LPS administration.Furthermore, LPS at lower levels ranging plus IL-6 effectively stimulated CFU-MK formation and increased CD41 expression and megakaryocyte polyploidization.Notably, the optimal LPS concentration in combination with IL-6 might be a novel stimulator of TLR4 and IL-6R expression in Dami cell lines, which initially occurs through TLR4-IL-6R crosstalk and then involves the activation of NF-κB and phosphorylation of p38 MAPK.

View Article: PubMed Central - PubMed

Affiliation: State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, China.

ABSTRACT
Lipopolysaccharide (LPS) induces platelet activation and enhances platelet sensitivity to aggregation, which might alter platelet counts. We found that serial doses of micro-concentration LPS significantly increased the platelet count in mice treated with kanamycin, along with increased expression of IL-6 compared with IL-3 and TPO in megakaryocytes obtained from the mouse bone morrow following LPS administration. Furthermore, LPS at lower levels ranging plus IL-6 effectively stimulated CFU-MK formation and increased CD41 expression and megakaryocyte polyploidization. Meanwhile, there was a sustained rise in the percentage of reticulated platelets in the whole blood in response to low-dosage LPS combined with IL-6. In vivo experiments also demonstrated that the administration of LPS combined with IL-6 substantially enhanced the number of circulating platelets in normal and thrombocytopenic mice. Notably, the optimal LPS concentration in combination with IL-6 might be a novel stimulator of TLR4 and IL-6R expression in Dami cell lines, which initially occurs through TLR4-IL-6R crosstalk and then involves the activation of NF-κB and phosphorylation of p38 MAPK. These data suggest a new paradigm for the regulation of megakaryocytopoiesis and platelet production via a synergistic effect of LPS and IL-6, which has the potential to be used for the design of new therapies.

No MeSH data available.


Related in: MedlinePlus