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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

Detection of RPs in the whole blood of mice.(A) Platelet fractions were identified by FACS forward-scatter and side-scatter parameters. The mean fluorescence intensity >1% of all platelets at baseline was used to set the threshold of the thiazole orange signal by analyzing 5000 platelets. Dot plots show the distribution of thiazole-positive events within the platelets in the whole blood. Regions are set on the RP percentage for blood samples from mice receiving LPS or IL-6 treatment alone or from LPS- plus IL-6-treated mice. The flow cytometric data were analyzed using a flow cytometer (Becton Dickinson) and CellQuest software. (B) Histogram showing the percentage of RPs stimulated by LPS and IL-6 in three independent experiments. *P < .05; **P < 0.01.
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f5: Detection of RPs in the whole blood of mice.(A) Platelet fractions were identified by FACS forward-scatter and side-scatter parameters. The mean fluorescence intensity >1% of all platelets at baseline was used to set the threshold of the thiazole orange signal by analyzing 5000 platelets. Dot plots show the distribution of thiazole-positive events within the platelets in the whole blood. Regions are set on the RP percentage for blood samples from mice receiving LPS or IL-6 treatment alone or from LPS- plus IL-6-treated mice. The flow cytometric data were analyzed using a flow cytometer (Becton Dickinson) and CellQuest software. (B) Histogram showing the percentage of RPs stimulated by LPS and IL-6 in three independent experiments. *P < .05; **P < 0.01.

Mentions: The RP population generally represents younger platelets with an increased mean volume and a greater number of dense granules than older circulating platelets24. Under control conditions (prior to LPS treatment), the percentage of RPs (containing mRNA) was significantly less than that in mice treated with IL-6 or IL-6 plus LPS. Approximately 16% and 7% of maternal platelets were reticulated following the IP injection of 100.0 μg/kg/day IL-6 and 0.8 μg/kg/day LPS for 7 d, respectively. However, more than 43% of the platelets were reticulated in the presence of IL-6 plus LPS. Unexpectedly, thiazole orange staining indicated that the number of RPs following 100.0 μg/kg/day IL-6 plus 80.0 μg/kg/day LPS treatment decreased to 5% of the platelets (Fig. 5A). Although the RPs levels of IL-6 alone or IL-6 plus LPS (0.8 μg/kg/day) was significantly more than that for the control, the RPs levels of IL-6 plus LPS (80.0 μg/kg/day) approached those seen in the control (Fig. 5B) Thus, the increased production of platelets could be partially related to the continually expanding megakaryocytic polyploidy at suitable stimulating doses of LPS plus IL-6. These results suggest that the continually expanding rnRNA synthesis during megakaryocyte maturation could lead to the production of platelets following LPS plus IL-6 administration.


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)

Detection of RPs in the whole blood of mice.(A) Platelet fractions were identified by FACS forward-scatter and side-scatter parameters. The mean fluorescence intensity >1% of all platelets at baseline was used to set the threshold of the thiazole orange signal by analyzing 5000 platelets. Dot plots show the distribution of thiazole-positive events within the platelets in the whole blood. Regions are set on the RP percentage for blood samples from mice receiving LPS or IL-6 treatment alone or from LPS- plus IL-6-treated mice. The flow cytometric data were analyzed using a flow cytometer (Becton Dickinson) and CellQuest software. (B) Histogram showing the percentage of RPs stimulated by LPS and IL-6 in three independent experiments. *P < .05; **P < 0.01.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4557119&req=5

f5: Detection of RPs in the whole blood of mice.(A) Platelet fractions were identified by FACS forward-scatter and side-scatter parameters. The mean fluorescence intensity >1% of all platelets at baseline was used to set the threshold of the thiazole orange signal by analyzing 5000 platelets. Dot plots show the distribution of thiazole-positive events within the platelets in the whole blood. Regions are set on the RP percentage for blood samples from mice receiving LPS or IL-6 treatment alone or from LPS- plus IL-6-treated mice. The flow cytometric data were analyzed using a flow cytometer (Becton Dickinson) and CellQuest software. (B) Histogram showing the percentage of RPs stimulated by LPS and IL-6 in three independent experiments. *P < .05; **P < 0.01.
Mentions: The RP population generally represents younger platelets with an increased mean volume and a greater number of dense granules than older circulating platelets24. Under control conditions (prior to LPS treatment), the percentage of RPs (containing mRNA) was significantly less than that in mice treated with IL-6 or IL-6 plus LPS. Approximately 16% and 7% of maternal platelets were reticulated following the IP injection of 100.0 μg/kg/day IL-6 and 0.8 μg/kg/day LPS for 7 d, respectively. However, more than 43% of the platelets were reticulated in the presence of IL-6 plus LPS. Unexpectedly, thiazole orange staining indicated that the number of RPs following 100.0 μg/kg/day IL-6 plus 80.0 μg/kg/day LPS treatment decreased to 5% of the platelets (Fig. 5A). Although the RPs levels of IL-6 alone or IL-6 plus LPS (0.8 μg/kg/day) was significantly more than that for the control, the RPs levels of IL-6 plus LPS (80.0 μg/kg/day) approached those seen in the control (Fig. 5B) Thus, the increased production of platelets could be partially related to the continually expanding megakaryocytic polyploidy at suitable stimulating doses of LPS plus IL-6. These results suggest that the continually expanding rnRNA synthesis during megakaryocyte maturation could lead to the production of platelets following LPS plus IL-6 administration.

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