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Interaction of fibrinogen and muramidase-released protein promotes the development of Streptococcus suis meningitis.

Wang J, Kong D, Zhang S, Jiang H, Zheng Y, Zang Y, Hao H, Jiang Y - Front Microbiol (2015)

Bottom Line: Muramidase-released protein (MRP) is as an important virulence marker of Streptococcus suis (S. suis) serotype 2.In this study, we found that the deletion of mrp significantly impairs the hFg-mediated adherence and traversal ability of S. suis across human cerebral microvascular endothelial cells (hCMEC/D3).Measurement of the permeability to Lucifer yellow in vitro and Evans blue extravasation in vivo show that the MRP-hFg interaction significantly increases the permeability of the blood-brain barrier (BBB).

View Article: PubMed Central - PubMed

Affiliation: State Key Laboratory of Pathogen and Biosecurity, Institute of Microbiology and Epidemiology, Academy of Military Medical Sciences , Beijing, China ; Urumqi Ethnic Cadres' College , Urumqi, China.

ABSTRACT
Muramidase-released protein (MRP) is as an important virulence marker of Streptococcus suis (S. suis) serotype 2. Our previous works have shown that MRP can bind human fibrinogen (hFg); however, the function of this interaction in S. suis meningitis is not known. In this study, we found that the deletion of mrp significantly impairs the hFg-mediated adherence and traversal ability of S. suis across human cerebral microvascular endothelial cells (hCMEC/D3). Measurement of the permeability to Lucifer yellow in vitro and Evans blue extravasation in vivo show that the MRP-hFg interaction significantly increases the permeability of the blood-brain barrier (BBB). In the mouse meningitis model, wild type S. suis caused higher bacterial loads in the brain and more severe histopathological signs of meningitis than the mrp mutant at day 3 post-infection. Western blot analysis and immunofluorescence observations reveal that the MRP-hFg interaction can destroy the cell adherens junction protein p120-catenin of hCMEC/D3. These results indicate that the MRP-hFg interaction is important in the development of S. suis meningitis.

No MeSH data available.


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MRP-hFg interaction increases the traversal ability of S. suis across the hCMEC/D3 cell monolayer. (A) The traversal rate of S. suis across the hCMEC/D3 monolayers. Confluent hCMEC/D3 cell monolayers pretreated with or without Fg were challenged with S. suis 05ZYH33 and 05ZYH33Δmrp for 25 min. The traversed bacteria in the basolateral chamber were enumerated by colony plate count. (B) The transendothelial permeability assay. Fg pretreated S. suis 05ZYH33 or 05ZYH33Δmrp were incubated with hCMEC/D3 cell monolayers in the presence of Lucifer yellow (200 μM) for 30 min. The amount of Lucifer yellow in the basolateral chamber was quantified with a spectrophotometer. D-mannitol was used as positive control as it disrupts cell–cell junctions. *P < 0.05, **P < 0.01.
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Figure 2: MRP-hFg interaction increases the traversal ability of S. suis across the hCMEC/D3 cell monolayer. (A) The traversal rate of S. suis across the hCMEC/D3 monolayers. Confluent hCMEC/D3 cell monolayers pretreated with or without Fg were challenged with S. suis 05ZYH33 and 05ZYH33Δmrp for 25 min. The traversed bacteria in the basolateral chamber were enumerated by colony plate count. (B) The transendothelial permeability assay. Fg pretreated S. suis 05ZYH33 or 05ZYH33Δmrp were incubated with hCMEC/D3 cell monolayers in the presence of Lucifer yellow (200 μM) for 30 min. The amount of Lucifer yellow in the basolateral chamber was quantified with a spectrophotometer. D-mannitol was used as positive control as it disrupts cell–cell junctions. *P < 0.05, **P < 0.01.

Mentions: The adherence of bacterium to human brain microvascular endothelial cells is thought to be important for invasion of the central nervous system (Charland et al., 2000). Since binding of MRP with Fg promotes the adherence of S. suis to hCMEC/D3 cell monolayers, we supposed that this interaction might increase the traversal of S. suis across hCMEC/D3 cell monolayers. To test this hypothesis, we pretreated the hCMEC/D3 cell monolayers with or without Fg before S. suis infection. Our results (Figure 2A) show that in the presence of hFg (20 μg/mL), both S. suis strain 05ZYH33 and 05ZYH33Δmrp increased their traversal abilities across the hCMEC/D3 cell monolayers. The traversal ratio of strain 05ZYH33 was significantly higher than that of the mutant strain 05ZYH33Δmrp. The transendothelial cell permeability assay (Figure 2B) also showed that in the presence of hFg, wild-type strain 05ZYH33 infection significantly increased the permeability of Lucifer yellow across the hCMEC/D3 cell monolayer compared to that of the mutant strain 05ZYH33Δmrp. Combined, these results indicate that the interactions of MRP and Fg increase the traversal of S. suis across human in vitro BBB by increasing the permeability of the hCMEC/D3 cell monolayer.


Interaction of fibrinogen and muramidase-released protein promotes the development of Streptococcus suis meningitis.

Wang J, Kong D, Zhang S, Jiang H, Zheng Y, Zang Y, Hao H, Jiang Y - Front Microbiol (2015)

MRP-hFg interaction increases the traversal ability of S. suis across the hCMEC/D3 cell monolayer. (A) The traversal rate of S. suis across the hCMEC/D3 monolayers. Confluent hCMEC/D3 cell monolayers pretreated with or without Fg were challenged with S. suis 05ZYH33 and 05ZYH33Δmrp for 25 min. The traversed bacteria in the basolateral chamber were enumerated by colony plate count. (B) The transendothelial permeability assay. Fg pretreated S. suis 05ZYH33 or 05ZYH33Δmrp were incubated with hCMEC/D3 cell monolayers in the presence of Lucifer yellow (200 μM) for 30 min. The amount of Lucifer yellow in the basolateral chamber was quantified with a spectrophotometer. D-mannitol was used as positive control as it disrupts cell–cell junctions. *P < 0.05, **P < 0.01.
© Copyright Policy
Related In: Results  -  Collection

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Show All Figures
getmorefigures.php?uid=PMC4585153&req=5

Figure 2: MRP-hFg interaction increases the traversal ability of S. suis across the hCMEC/D3 cell monolayer. (A) The traversal rate of S. suis across the hCMEC/D3 monolayers. Confluent hCMEC/D3 cell monolayers pretreated with or without Fg were challenged with S. suis 05ZYH33 and 05ZYH33Δmrp for 25 min. The traversed bacteria in the basolateral chamber were enumerated by colony plate count. (B) The transendothelial permeability assay. Fg pretreated S. suis 05ZYH33 or 05ZYH33Δmrp were incubated with hCMEC/D3 cell monolayers in the presence of Lucifer yellow (200 μM) for 30 min. The amount of Lucifer yellow in the basolateral chamber was quantified with a spectrophotometer. D-mannitol was used as positive control as it disrupts cell–cell junctions. *P < 0.05, **P < 0.01.
Mentions: The adherence of bacterium to human brain microvascular endothelial cells is thought to be important for invasion of the central nervous system (Charland et al., 2000). Since binding of MRP with Fg promotes the adherence of S. suis to hCMEC/D3 cell monolayers, we supposed that this interaction might increase the traversal of S. suis across hCMEC/D3 cell monolayers. To test this hypothesis, we pretreated the hCMEC/D3 cell monolayers with or without Fg before S. suis infection. Our results (Figure 2A) show that in the presence of hFg (20 μg/mL), both S. suis strain 05ZYH33 and 05ZYH33Δmrp increased their traversal abilities across the hCMEC/D3 cell monolayers. The traversal ratio of strain 05ZYH33 was significantly higher than that of the mutant strain 05ZYH33Δmrp. The transendothelial cell permeability assay (Figure 2B) also showed that in the presence of hFg, wild-type strain 05ZYH33 infection significantly increased the permeability of Lucifer yellow across the hCMEC/D3 cell monolayer compared to that of the mutant strain 05ZYH33Δmrp. Combined, these results indicate that the interactions of MRP and Fg increase the traversal of S. suis across human in vitro BBB by increasing the permeability of the hCMEC/D3 cell monolayer.

Bottom Line: Muramidase-released protein (MRP) is as an important virulence marker of Streptococcus suis (S. suis) serotype 2.In this study, we found that the deletion of mrp significantly impairs the hFg-mediated adherence and traversal ability of S. suis across human cerebral microvascular endothelial cells (hCMEC/D3).Measurement of the permeability to Lucifer yellow in vitro and Evans blue extravasation in vivo show that the MRP-hFg interaction significantly increases the permeability of the blood-brain barrier (BBB).

View Article: PubMed Central - PubMed

Affiliation: State Key Laboratory of Pathogen and Biosecurity, Institute of Microbiology and Epidemiology, Academy of Military Medical Sciences , Beijing, China ; Urumqi Ethnic Cadres' College , Urumqi, China.

ABSTRACT
Muramidase-released protein (MRP) is as an important virulence marker of Streptococcus suis (S. suis) serotype 2. Our previous works have shown that MRP can bind human fibrinogen (hFg); however, the function of this interaction in S. suis meningitis is not known. In this study, we found that the deletion of mrp significantly impairs the hFg-mediated adherence and traversal ability of S. suis across human cerebral microvascular endothelial cells (hCMEC/D3). Measurement of the permeability to Lucifer yellow in vitro and Evans blue extravasation in vivo show that the MRP-hFg interaction significantly increases the permeability of the blood-brain barrier (BBB). In the mouse meningitis model, wild type S. suis caused higher bacterial loads in the brain and more severe histopathological signs of meningitis than the mrp mutant at day 3 post-infection. Western blot analysis and immunofluorescence observations reveal that the MRP-hFg interaction can destroy the cell adherens junction protein p120-catenin of hCMEC/D3. These results indicate that the MRP-hFg interaction is important in the development of S. suis meningitis.

No MeSH data available.


Related in: MedlinePlus