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Specific Inflammatory Stimuli Lead to Distinct Platelet Responses in Mice and Humans.

Beaulieu LM, Clancy L, Tanriverdi K, Benjamin EJ, Kramer CD, Weinberg EO, He X, Mekasha S, Mick E, Ingalls RR, Genco CA, Freedman JE - PLoS ONE (2015)

Bottom Line: At week 9, these cells individually localized to the spleen, while Western diet resulted in increased platelet-neutrophil aggregates in the spleen only.Results were reinforced in platelets obtained from participants of the FHS.Using both human studies and animal models, results demonstrate that variable sources of inflammatory stimuli have the ability to influence the platelet phenotype in distinct ways, indicative of the diverse function of platelets in thrombosis, hemostasis, and immunity.

View Article: PubMed Central - PubMed

Affiliation: University of Massachusetts Medical School, Department of Medicine, Division of Cardiovascular Medicine, Worcester, MA, United States of America.

ABSTRACT

Introduction: Diverse and multi-factorial processes contribute to the progression of cardiovascular disease. These processes affect cells involved in the development of this disease in varying ways, ultimately leading to atherothrombosis. The goal of our study was to compare the differential effects of specific stimuli--two bacterial infections and a Western diet--on platelet responses in ApoE-/- mice, specifically examining inflammatory function and gene expression. Results from murine studies were verified using platelets from participants of the Framingham Heart Study (FHS; n = 1819 participants).

Methods: Blood and spleen samples were collected at weeks 1 and 9 from ApoE-/- mice infected with Porphyromonas gingivalis or Chlamydia pneumoniae and from mice fed a Western diet for 9 weeks. Transcripts based on data from a Western diet in ApoE-/- mice were measured in platelet samples from FHS using high throughput qRT-PCR.

Results: At week 1, both bacterial infections increased circulating platelet-neutrophil aggregates. At week 9, these cells individually localized to the spleen, while Western diet resulted in increased platelet-neutrophil aggregates in the spleen only. Microarray analysis of platelet RNA from infected or Western diet-fed mice at week 1 and 9 showed differential profiles. Genes, such as Serpina1a, Ttr, Fgg, Rpl21, and Alb, were uniquely affected by infection and diet. Results were reinforced in platelets obtained from participants of the FHS.

Conclusion: Using both human studies and animal models, results demonstrate that variable sources of inflammatory stimuli have the ability to influence the platelet phenotype in distinct ways, indicative of the diverse function of platelets in thrombosis, hemostasis, and immunity.

No MeSH data available.


Related in: MedlinePlus

Platelet and neutrophil content in spleens in ApoE-/- mice with infection and diet.(A) Spleen sections from ApoE-/- mice at week 1 and week 9 were stained for CD41 (platelet marker; Alexa Fluor 405) and Ly6G (neutrophils; Texas Red) and visualized by confocal microscopy at 63X. The amount of CD41 staining (area; B), Ly6G staining (area; C), and the overlap of each signal (% pixels with overlapping signal); (D) were quantified. Data is normally distributed and analyzed using an ANOVA. n = 3 for each condition; ***p<0.001 compared to Untreated Control. Scale Bar in merged images = 50.0 μm.
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pone.0131688.g007: Platelet and neutrophil content in spleens in ApoE-/- mice with infection and diet.(A) Spleen sections from ApoE-/- mice at week 1 and week 9 were stained for CD41 (platelet marker; Alexa Fluor 405) and Ly6G (neutrophils; Texas Red) and visualized by confocal microscopy at 63X. The amount of CD41 staining (area; B), Ly6G staining (area; C), and the overlap of each signal (% pixels with overlapping signal); (D) were quantified. Data is normally distributed and analyzed using an ANOVA. n = 3 for each condition; ***p<0.001 compared to Untreated Control. Scale Bar in merged images = 50.0 μm.

Mentions: There were no changes in body mass (Fig 4), or increases in white blood cell (WBC) counts (Fig 5A) at week 1 in ApoE-/- mice infected with either P. gingivalis or C. pneumoniae. Only C. pneumoniae altered platelet counts (Fig 5B) compared to Untreated Control, although not significantly, suggesting this bacterial infection altered megakaryocyte maturation and platelet production and/or platelet clearance. Circulating heterotypic aggregates (platelet-neutrophil aggregates) were significantly increased in C. pneumoniae infected mice at week 1 (Fig 6); however, there were inconsistencies with the P. gingivalis-infected ApoE-/- mice, but the data suggest that there was an increase in aggregate formation as well. Analysis of spleen sections from P. gingivalis or C. pneumoniae infected mice revealed increased CD41 levels, a platelet marker, and Ly6G levels, a neutrophil marker (Fig 7A–7C; IgG controls in S1 Fig). However, there were no heterotypic aggregates as indicated by the lack of overlap between the two signals when merged (Fig 7A and 7D).


Specific Inflammatory Stimuli Lead to Distinct Platelet Responses in Mice and Humans.

Beaulieu LM, Clancy L, Tanriverdi K, Benjamin EJ, Kramer CD, Weinberg EO, He X, Mekasha S, Mick E, Ingalls RR, Genco CA, Freedman JE - PLoS ONE (2015)

Platelet and neutrophil content in spleens in ApoE-/- mice with infection and diet.(A) Spleen sections from ApoE-/- mice at week 1 and week 9 were stained for CD41 (platelet marker; Alexa Fluor 405) and Ly6G (neutrophils; Texas Red) and visualized by confocal microscopy at 63X. The amount of CD41 staining (area; B), Ly6G staining (area; C), and the overlap of each signal (% pixels with overlapping signal); (D) were quantified. Data is normally distributed and analyzed using an ANOVA. n = 3 for each condition; ***p<0.001 compared to Untreated Control. Scale Bar in merged images = 50.0 μm.
© Copyright Policy
Related In: Results  -  Collection

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getmorefigures.php?uid=PMC4493099&req=5

pone.0131688.g007: Platelet and neutrophil content in spleens in ApoE-/- mice with infection and diet.(A) Spleen sections from ApoE-/- mice at week 1 and week 9 were stained for CD41 (platelet marker; Alexa Fluor 405) and Ly6G (neutrophils; Texas Red) and visualized by confocal microscopy at 63X. The amount of CD41 staining (area; B), Ly6G staining (area; C), and the overlap of each signal (% pixels with overlapping signal); (D) were quantified. Data is normally distributed and analyzed using an ANOVA. n = 3 for each condition; ***p<0.001 compared to Untreated Control. Scale Bar in merged images = 50.0 μm.
Mentions: There were no changes in body mass (Fig 4), or increases in white blood cell (WBC) counts (Fig 5A) at week 1 in ApoE-/- mice infected with either P. gingivalis or C. pneumoniae. Only C. pneumoniae altered platelet counts (Fig 5B) compared to Untreated Control, although not significantly, suggesting this bacterial infection altered megakaryocyte maturation and platelet production and/or platelet clearance. Circulating heterotypic aggregates (platelet-neutrophil aggregates) were significantly increased in C. pneumoniae infected mice at week 1 (Fig 6); however, there were inconsistencies with the P. gingivalis-infected ApoE-/- mice, but the data suggest that there was an increase in aggregate formation as well. Analysis of spleen sections from P. gingivalis or C. pneumoniae infected mice revealed increased CD41 levels, a platelet marker, and Ly6G levels, a neutrophil marker (Fig 7A–7C; IgG controls in S1 Fig). However, there were no heterotypic aggregates as indicated by the lack of overlap between the two signals when merged (Fig 7A and 7D).

Bottom Line: At week 9, these cells individually localized to the spleen, while Western diet resulted in increased platelet-neutrophil aggregates in the spleen only.Results were reinforced in platelets obtained from participants of the FHS.Using both human studies and animal models, results demonstrate that variable sources of inflammatory stimuli have the ability to influence the platelet phenotype in distinct ways, indicative of the diverse function of platelets in thrombosis, hemostasis, and immunity.

View Article: PubMed Central - PubMed

Affiliation: University of Massachusetts Medical School, Department of Medicine, Division of Cardiovascular Medicine, Worcester, MA, United States of America.

ABSTRACT

Introduction: Diverse and multi-factorial processes contribute to the progression of cardiovascular disease. These processes affect cells involved in the development of this disease in varying ways, ultimately leading to atherothrombosis. The goal of our study was to compare the differential effects of specific stimuli--two bacterial infections and a Western diet--on platelet responses in ApoE-/- mice, specifically examining inflammatory function and gene expression. Results from murine studies were verified using platelets from participants of the Framingham Heart Study (FHS; n = 1819 participants).

Methods: Blood and spleen samples were collected at weeks 1 and 9 from ApoE-/- mice infected with Porphyromonas gingivalis or Chlamydia pneumoniae and from mice fed a Western diet for 9 weeks. Transcripts based on data from a Western diet in ApoE-/- mice were measured in platelet samples from FHS using high throughput qRT-PCR.

Results: At week 1, both bacterial infections increased circulating platelet-neutrophil aggregates. At week 9, these cells individually localized to the spleen, while Western diet resulted in increased platelet-neutrophil aggregates in the spleen only. Microarray analysis of platelet RNA from infected or Western diet-fed mice at week 1 and 9 showed differential profiles. Genes, such as Serpina1a, Ttr, Fgg, Rpl21, and Alb, were uniquely affected by infection and diet. Results were reinforced in platelets obtained from participants of the FHS.

Conclusion: Using both human studies and animal models, results demonstrate that variable sources of inflammatory stimuli have the ability to influence the platelet phenotype in distinct ways, indicative of the diverse function of platelets in thrombosis, hemostasis, and immunity.

No MeSH data available.


Related in: MedlinePlus