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The impact of juvenile coxsackievirus infection on cardiac progenitor cells and postnatal heart development.

Sin J, Puccini JM, Huang C, Konstandin MH, Gilbert PE, Sussman MA, Gottlieb RA, Feuer R - PLoS Pathog. (2014)

Bottom Line: Chronic consequences of mild CVB infection are unknown, though there is an epidemiologic association between early subclinical infections and late heart failure, raising the possibility of subtle damage leading to late-onset dysfunction, or chronic ongoing injury due to inflammatory reactions during latent infection.Moreover, CVB3 efficiently infected juvenile c-kit+ cells, and cardiac progenitor cell numbers were reduced in the hearts of juvenile-infected adult mice.These results suggest that the exhausted cardiac progenitor cell pool following juvenile CVB3 infection may impair the heart's ability to increase capillary density to adapt to increased load.

View Article: PubMed Central - PubMed

Affiliation: Donald P. Shiley BioScience Center, San Diego State University, San Diego, California, United States of America.

ABSTRACT
Coxsackievirus B (CVB) is an enterovirus that most commonly causes a self-limited febrile illness in infants, but cases of severe infection can manifest in acute myocarditis. Chronic consequences of mild CVB infection are unknown, though there is an epidemiologic association between early subclinical infections and late heart failure, raising the possibility of subtle damage leading to late-onset dysfunction, or chronic ongoing injury due to inflammatory reactions during latent infection. Here we describe a mouse model of juvenile infection with a subclinical dose of coxsackievirus B3 (CVB3) which showed no evident symptoms, either immediately following infection or in adult mice. However following physiological or pharmacologically-induced cardiac stress, juvenile-infected adult mice underwent cardiac hypertrophy and dilation indicative of progression to heart failure. Evaluation of the vasculature in the hearts of adult mice subjected to cardiac stress showed a compensatory increase in CD31+ blood vessel formation, although this effect was suppressed in juvenile-infected mice. Moreover, CVB3 efficiently infected juvenile c-kit+ cells, and cardiac progenitor cell numbers were reduced in the hearts of juvenile-infected adult mice. These results suggest that the exhausted cardiac progenitor cell pool following juvenile CVB3 infection may impair the heart's ability to increase capillary density to adapt to increased load.

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Juvenile CVB3 infection triggered growth arrest in CPCs.Three day-old mice were infected with eGFP-CVB3 (105 pfu IP) or mock-infected, and hearts were isolated at 2 days PI. Paraffin-embedded sections of heart tissue were deparaffinized and stained using antibodies against Ki67, Sca-1, and c-kit. (A) Immunofluorescence microscopy revealed a sharp decline in Ki67+ cells in the neonatal myocardium at 2 days PI. (B) The decline of Ki67+ cells in the infected heart was quantified and shown to be statistically significant (*p<0.05; Student's T-test) using ImageJ software. (C) Immunostaining for Sca-1 and Ki67 showed a marked increase in the number of Sca-1+ cells in the infected heart at 2 days PI. However, these cells were predominantly negative for Ki67, indicating the lack of cellular proliferation. (D) Quantification of c-kit and Ki67 colocalization showed a significant decrease in the percentage of cycling c-kit+ cells in the heart at 2 days PI (**p<0.01; Student's T-test). Representative images for three infected or mock-infected mice are shown.
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ppat-1004249-g005: Juvenile CVB3 infection triggered growth arrest in CPCs.Three day-old mice were infected with eGFP-CVB3 (105 pfu IP) or mock-infected, and hearts were isolated at 2 days PI. Paraffin-embedded sections of heart tissue were deparaffinized and stained using antibodies against Ki67, Sca-1, and c-kit. (A) Immunofluorescence microscopy revealed a sharp decline in Ki67+ cells in the neonatal myocardium at 2 days PI. (B) The decline of Ki67+ cells in the infected heart was quantified and shown to be statistically significant (*p<0.05; Student's T-test) using ImageJ software. (C) Immunostaining for Sca-1 and Ki67 showed a marked increase in the number of Sca-1+ cells in the infected heart at 2 days PI. However, these cells were predominantly negative for Ki67, indicating the lack of cellular proliferation. (D) Quantification of c-kit and Ki67 colocalization showed a significant decrease in the percentage of cycling c-kit+ cells in the heart at 2 days PI (**p<0.01; Student's T-test). Representative images for three infected or mock-infected mice are shown.

Mentions: Because many viruses including CVB3 are known to alter the cell cycle, heart sections were immunostained using antibodies against c-kit, Sca-1 and the proliferation marker, Ki67. A reduction in the number of Ki67+ cycling cells in hearts was observed in infected animals at 2 days PI relative to mock-infected controls (Figure 5A), and these results were quantified by ImageJ analysis (Figure 5B). Although we observed an early increase in the number of Sca-1+ cells in the heart early after infection suggesting an initial rapid expansion of progenitor cells, Sca-1+ cells predominantly lacked Ki67 expression by 2 days PI consistent with its proposed role as a cell cycle suppressor (Figure 5C). Immunostaining for both Ki67 and c-kit revealed a significant reduction in the number of proliferating c-kit+ cells in the hearts of infected pups (Figure 5D; **p<0.01).


The impact of juvenile coxsackievirus infection on cardiac progenitor cells and postnatal heart development.

Sin J, Puccini JM, Huang C, Konstandin MH, Gilbert PE, Sussman MA, Gottlieb RA, Feuer R - PLoS Pathog. (2014)

Juvenile CVB3 infection triggered growth arrest in CPCs.Three day-old mice were infected with eGFP-CVB3 (105 pfu IP) or mock-infected, and hearts were isolated at 2 days PI. Paraffin-embedded sections of heart tissue were deparaffinized and stained using antibodies against Ki67, Sca-1, and c-kit. (A) Immunofluorescence microscopy revealed a sharp decline in Ki67+ cells in the neonatal myocardium at 2 days PI. (B) The decline of Ki67+ cells in the infected heart was quantified and shown to be statistically significant (*p<0.05; Student's T-test) using ImageJ software. (C) Immunostaining for Sca-1 and Ki67 showed a marked increase in the number of Sca-1+ cells in the infected heart at 2 days PI. However, these cells were predominantly negative for Ki67, indicating the lack of cellular proliferation. (D) Quantification of c-kit and Ki67 colocalization showed a significant decrease in the percentage of cycling c-kit+ cells in the heart at 2 days PI (**p<0.01; Student's T-test). Representative images for three infected or mock-infected mice are shown.
© Copyright Policy
Related In: Results  -  Collection

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Show All Figures
getmorefigures.php?uid=PMC4117602&req=5

ppat-1004249-g005: Juvenile CVB3 infection triggered growth arrest in CPCs.Three day-old mice were infected with eGFP-CVB3 (105 pfu IP) or mock-infected, and hearts were isolated at 2 days PI. Paraffin-embedded sections of heart tissue were deparaffinized and stained using antibodies against Ki67, Sca-1, and c-kit. (A) Immunofluorescence microscopy revealed a sharp decline in Ki67+ cells in the neonatal myocardium at 2 days PI. (B) The decline of Ki67+ cells in the infected heart was quantified and shown to be statistically significant (*p<0.05; Student's T-test) using ImageJ software. (C) Immunostaining for Sca-1 and Ki67 showed a marked increase in the number of Sca-1+ cells in the infected heart at 2 days PI. However, these cells were predominantly negative for Ki67, indicating the lack of cellular proliferation. (D) Quantification of c-kit and Ki67 colocalization showed a significant decrease in the percentage of cycling c-kit+ cells in the heart at 2 days PI (**p<0.01; Student's T-test). Representative images for three infected or mock-infected mice are shown.
Mentions: Because many viruses including CVB3 are known to alter the cell cycle, heart sections were immunostained using antibodies against c-kit, Sca-1 and the proliferation marker, Ki67. A reduction in the number of Ki67+ cycling cells in hearts was observed in infected animals at 2 days PI relative to mock-infected controls (Figure 5A), and these results were quantified by ImageJ analysis (Figure 5B). Although we observed an early increase in the number of Sca-1+ cells in the heart early after infection suggesting an initial rapid expansion of progenitor cells, Sca-1+ cells predominantly lacked Ki67 expression by 2 days PI consistent with its proposed role as a cell cycle suppressor (Figure 5C). Immunostaining for both Ki67 and c-kit revealed a significant reduction in the number of proliferating c-kit+ cells in the hearts of infected pups (Figure 5D; **p<0.01).

Bottom Line: Chronic consequences of mild CVB infection are unknown, though there is an epidemiologic association between early subclinical infections and late heart failure, raising the possibility of subtle damage leading to late-onset dysfunction, or chronic ongoing injury due to inflammatory reactions during latent infection.Moreover, CVB3 efficiently infected juvenile c-kit+ cells, and cardiac progenitor cell numbers were reduced in the hearts of juvenile-infected adult mice.These results suggest that the exhausted cardiac progenitor cell pool following juvenile CVB3 infection may impair the heart's ability to increase capillary density to adapt to increased load.

View Article: PubMed Central - PubMed

Affiliation: Donald P. Shiley BioScience Center, San Diego State University, San Diego, California, United States of America.

ABSTRACT
Coxsackievirus B (CVB) is an enterovirus that most commonly causes a self-limited febrile illness in infants, but cases of severe infection can manifest in acute myocarditis. Chronic consequences of mild CVB infection are unknown, though there is an epidemiologic association between early subclinical infections and late heart failure, raising the possibility of subtle damage leading to late-onset dysfunction, or chronic ongoing injury due to inflammatory reactions during latent infection. Here we describe a mouse model of juvenile infection with a subclinical dose of coxsackievirus B3 (CVB3) which showed no evident symptoms, either immediately following infection or in adult mice. However following physiological or pharmacologically-induced cardiac stress, juvenile-infected adult mice underwent cardiac hypertrophy and dilation indicative of progression to heart failure. Evaluation of the vasculature in the hearts of adult mice subjected to cardiac stress showed a compensatory increase in CD31+ blood vessel formation, although this effect was suppressed in juvenile-infected mice. Moreover, CVB3 efficiently infected juvenile c-kit+ cells, and cardiac progenitor cell numbers were reduced in the hearts of juvenile-infected adult mice. These results suggest that the exhausted cardiac progenitor cell pool following juvenile CVB3 infection may impair the heart's ability to increase capillary density to adapt to increased load.

Show MeSH
Related in: MedlinePlus