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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

Genes upregulated and downregulated at week 1 in ApoE-/- mice with bacterial infection.Heatmap shows the transcripts identified through microarray as upregulated or downregulated 2-fold or more with either P. gingivalis (Pg) or C. pneumoniae (Cp) infection compared to Untreated Control in the ApoE-/- mice. Each condition represents RNA from 3 mice pooled.
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pone.0131688.g001: Genes upregulated and downregulated at week 1 in ApoE-/- mice with bacterial infection.Heatmap shows the transcripts identified through microarray as upregulated or downregulated 2-fold or more with either P. gingivalis (Pg) or C. pneumoniae (Cp) infection compared to Untreated Control in the ApoE-/- mice. Each condition represents RNA from 3 mice pooled.

Mentions: ApoE-/- mice (n = 3) were infected orally with P. gingivalis or intranasally with C. pneumoniae. One day after the last oral infection with P. gingivalis and 4 days after the last intranasal infection with C. pneumoniae (week 1), platelet RNA was isolated and pooled to generate a sufficient amount of RNA per condition for microarray analysis. Due to the small sample size, only genes up- or downregulated 2-fold or greater and pathways with a normalized enrichment score (NES) ≥ ~2/-2, nominal p-value (Nom p) <0.05, and a false discovery rate (FDR q) <0.05 were considered. Additionally, this data was intended to generate hypotheses on how platelets and platelet transcripts are affected by different inflammatory stimuli over time. During Week 1, we observed increased expression of 129 genes and decreased expression in 59 genes following P. gingivalis infection compared to Untreated Controls (Fig 1). The top five upregulated genes with known function were SERPINA1A (27.09-fold), ALB (17.83-fold), TTR (15.84-fold), APOA2 (15.08-fold), and KNG1 (13.01-fold). The top 5 downregulated genes were STARD6 (-5.49-fold), SPIC (-5.42-fold), HMOX1 (-4.60-fold), IGK-V21-4 (-3.08-fold), and RASSF4 (-2.89-fold). Using Gene Set Enrichment Analysis (GSEA), we identified gene sets with increased expression following P. gingivalis infection with an NES ≥2, a Nom p <0.05, and an FDR q <0.05. These gene sets included coagulation, lipids, signaling pathways, RNA/gene expression, and inflammation (S1 Table). Gene sets, which exhibited decreased expression, included those involved in enzyme activity, differentiation, metabolism, extracellular matrix related, signaling, and cytoskeleton pathways; however, these gene sets were not significant (NES ˃-2, FDR q ˃0.05; S2 Table).


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)

Genes upregulated and downregulated at week 1 in ApoE-/- mice with bacterial infection.Heatmap shows the transcripts identified through microarray as upregulated or downregulated 2-fold or more with either P. gingivalis (Pg) or C. pneumoniae (Cp) infection compared to Untreated Control in the ApoE-/- mice. Each condition represents RNA from 3 mice pooled.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4493099&req=5

pone.0131688.g001: Genes upregulated and downregulated at week 1 in ApoE-/- mice with bacterial infection.Heatmap shows the transcripts identified through microarray as upregulated or downregulated 2-fold or more with either P. gingivalis (Pg) or C. pneumoniae (Cp) infection compared to Untreated Control in the ApoE-/- mice. Each condition represents RNA from 3 mice pooled.
Mentions: ApoE-/- mice (n = 3) were infected orally with P. gingivalis or intranasally with C. pneumoniae. One day after the last oral infection with P. gingivalis and 4 days after the last intranasal infection with C. pneumoniae (week 1), platelet RNA was isolated and pooled to generate a sufficient amount of RNA per condition for microarray analysis. Due to the small sample size, only genes up- or downregulated 2-fold or greater and pathways with a normalized enrichment score (NES) ≥ ~2/-2, nominal p-value (Nom p) <0.05, and a false discovery rate (FDR q) <0.05 were considered. Additionally, this data was intended to generate hypotheses on how platelets and platelet transcripts are affected by different inflammatory stimuli over time. During Week 1, we observed increased expression of 129 genes and decreased expression in 59 genes following P. gingivalis infection compared to Untreated Controls (Fig 1). The top five upregulated genes with known function were SERPINA1A (27.09-fold), ALB (17.83-fold), TTR (15.84-fold), APOA2 (15.08-fold), and KNG1 (13.01-fold). The top 5 downregulated genes were STARD6 (-5.49-fold), SPIC (-5.42-fold), HMOX1 (-4.60-fold), IGK-V21-4 (-3.08-fold), and RASSF4 (-2.89-fold). Using Gene Set Enrichment Analysis (GSEA), we identified gene sets with increased expression following P. gingivalis infection with an NES ≥2, a Nom p <0.05, and an FDR q <0.05. These gene sets included coagulation, lipids, signaling pathways, RNA/gene expression, and inflammation (S1 Table). Gene sets, which exhibited decreased expression, included those involved in enzyme activity, differentiation, metabolism, extracellular matrix related, signaling, and cytoskeleton pathways; however, these gene sets were not significant (NES ˃-2, FDR q ˃0.05; S2 Table).

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