Limits...
Investigating the Mechanism of Hyperglycemia-Induced Fetal Cardiac Hypertrophy.

Han SS, Wang G, Jin Y, Ma ZL, Jia WJ, Wu X, Wang XY, He MY, Cheng X, Li WJ, Yang X, Liu GS - PLoS ONE (2015)

Bottom Line: Next, we found that the individual cardiomyocyte size increased in pre-gestational diabetes mellitus mice and in response to high glucose exposure.Meanwhile, the expression of β-MHC and BMP-10 was up-regulated.In cultured H9c2 cells exposed to high glucose, Nkx2.5 expression decreased, as detected by both immunostaining and western blotting, and the expression of KCNE1 and Cx43 was also restricted.

View Article: PubMed Central - PubMed

Affiliation: Department of Pediatrics and Neonatology, Institute of Fetal-Preterm Labor Medicine, The First Affiliated Hospital, Jinan University, Guangzhou, 510630, China.

ABSTRACT
Hyperglycemia in diabetic mothers enhances the risk of fetal cardiac hypertrophy during gestation. However, the mechanism of high-glucose-induced cardiac hypertrophy is not largely understood. In this study, we first demonstrated that the incidence rate of cardiac hypertrophy dramatically increased in fetuses of diabetic mothers using color ultrasound examination. In addition, human fetal cardiac hypertrophy was successfully mimicked in a streptozotocin (STZ)-induced diabetes mouse model, in which mouse cardiac hypertrophy was diagnosed using type-M ultrasound and a histological assay. PH3 immunofluorescent staining of mouse fetal hearts and in vitro-cultured H9c2 cells indicated that cell proliferation decreased in E18.5, E15.5 and E13.5 mice, and cell apoptosis in H9c2 cells increased in the presence of high glucose in a dose-dependent manner. Next, we found that the individual cardiomyocyte size increased in pre-gestational diabetes mellitus mice and in response to high glucose exposure. Meanwhile, the expression of β-MHC and BMP-10 was up-regulated. Nkx2.5 immunofluorescent staining showed that the expression of Nkx2.5, a crucial cardiac transcription factor, was suppressed in the ventricular septum, left ventricular wall and right ventricular wall of E18.5, E15.5 and E13.5 mouse hearts. However, cardiac hypertrophy did not morphologically occur in E13.5 mouse hearts. In cultured H9c2 cells exposed to high glucose, Nkx2.5 expression decreased, as detected by both immunostaining and western blotting, and the expression of KCNE1 and Cx43 was also restricted. Taken together, alterations in cell size rather than cell proliferation or apoptosis are responsible for hyperglycemia-induced fetal cardiac hypertrophy. The aberrant expression of Nkx2.5 and its regulatory target genes in the presence of high glucose could be a principal component of pathogenesis in the development of fetal cardiac hypertrophy.

No MeSH data available.


Related in: MedlinePlus

Exposure to high glucose suppressed Nkx2.5 and its downstream gene expressions in cultured cardiomyocytes.The H9c2 cells were incubated in vitro with various concentrations of glucose for 72 hours. Nkx2.5 immunofluorescent staining (red) was performed on the cultured cells. All of the cultured cells were counterstained with DAPI (blue). A-C: The representative bright-field images of the cells from the 5.5-mmol/l (A), 25-mmol/l (B) and 50-mmol/l (C) groups at 72 hours of incubation. A1-C1: The representative Nkx2.5 immunofluorescent staining images from the 5.5-mmol/l (A1), 25-mmol/l (B1) and 50-mmol/l (C1) groups. A2-C2: A1-C1 + DAPI counterstain. D: The bar charts showing the percentages of Nkx2.5+ cells/DAPI+ cells in the 5.5-mmol/l, 25-mmol/l and 50-mmol/l groups. E: Western blot data showing Nkx2.5 expression at the protein level in the 5.5-mmol/l, 25-mmol/l and 50-mmol/l groups. F: RT-PCR data showing the mRNA level of KCNE1 and Cx43 in the 5.5-mmol/l, 25-mmol/l and 50-mmol/l groups. *P<0.05 vs control. Scale bars: 100 μm in A-C, A1-C2.
© Copyright Policy
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4587747&req=5

pone.0139141.g009: Exposure to high glucose suppressed Nkx2.5 and its downstream gene expressions in cultured cardiomyocytes.The H9c2 cells were incubated in vitro with various concentrations of glucose for 72 hours. Nkx2.5 immunofluorescent staining (red) was performed on the cultured cells. All of the cultured cells were counterstained with DAPI (blue). A-C: The representative bright-field images of the cells from the 5.5-mmol/l (A), 25-mmol/l (B) and 50-mmol/l (C) groups at 72 hours of incubation. A1-C1: The representative Nkx2.5 immunofluorescent staining images from the 5.5-mmol/l (A1), 25-mmol/l (B1) and 50-mmol/l (C1) groups. A2-C2: A1-C1 + DAPI counterstain. D: The bar charts showing the percentages of Nkx2.5+ cells/DAPI+ cells in the 5.5-mmol/l, 25-mmol/l and 50-mmol/l groups. E: Western blot data showing Nkx2.5 expression at the protein level in the 5.5-mmol/l, 25-mmol/l and 50-mmol/l groups. F: RT-PCR data showing the mRNA level of KCNE1 and Cx43 in the 5.5-mmol/l, 25-mmol/l and 50-mmol/l groups. *P<0.05 vs control. Scale bars: 100 μm in A-C, A1-C2.

Mentions: H9c2 cells that were exposed to a variety of concentrations of glucose in vitro were used to determine the effect of the expression of Nkx2.5 and its downstream genes in regulating heart formation (Fig 9A–9C). Nkx2.5 immunofluorescent staining showed that the percentage of Nkx2.5+ cell number/total cell number (DAPI+ cells) in the 50-mmol/l group (15.40±11.36%, n = 4) was significantly less than that in the 5.5-mmol/l (control) group (33.79±5.96%, n = 4; P<0.05), suggesting that high glucose (50 mmol/l) exposure suppressed the expression of Nkx2.5 compared to that of the control (5.5 mmol/l). Furthermore, western blotting data also indicated the same inhibitive tendency for Nkx2.5 expression at the protein level (Fig 9E). Meanwhile, we detected the expressions of KCNE1 and Cx43, the genes downstream of Nkx2.5, and the RT-PCR data showed that these genes were down-regulated simultaneously (Fig 9F), indicating that the expression of KCNE1 and Cx43 was affected by the down-regulation of Nkx2.5 induced by the high glucose level in PGDM.


Investigating the Mechanism of Hyperglycemia-Induced Fetal Cardiac Hypertrophy.

Han SS, Wang G, Jin Y, Ma ZL, Jia WJ, Wu X, Wang XY, He MY, Cheng X, Li WJ, Yang X, Liu GS - PLoS ONE (2015)

Exposure to high glucose suppressed Nkx2.5 and its downstream gene expressions in cultured cardiomyocytes.The H9c2 cells were incubated in vitro with various concentrations of glucose for 72 hours. Nkx2.5 immunofluorescent staining (red) was performed on the cultured cells. All of the cultured cells were counterstained with DAPI (blue). A-C: The representative bright-field images of the cells from the 5.5-mmol/l (A), 25-mmol/l (B) and 50-mmol/l (C) groups at 72 hours of incubation. A1-C1: The representative Nkx2.5 immunofluorescent staining images from the 5.5-mmol/l (A1), 25-mmol/l (B1) and 50-mmol/l (C1) groups. A2-C2: A1-C1 + DAPI counterstain. D: The bar charts showing the percentages of Nkx2.5+ cells/DAPI+ cells in the 5.5-mmol/l, 25-mmol/l and 50-mmol/l groups. E: Western blot data showing Nkx2.5 expression at the protein level in the 5.5-mmol/l, 25-mmol/l and 50-mmol/l groups. F: RT-PCR data showing the mRNA level of KCNE1 and Cx43 in the 5.5-mmol/l, 25-mmol/l and 50-mmol/l groups. *P<0.05 vs control. Scale bars: 100 μm in A-C, A1-C2.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4587747&req=5

pone.0139141.g009: Exposure to high glucose suppressed Nkx2.5 and its downstream gene expressions in cultured cardiomyocytes.The H9c2 cells were incubated in vitro with various concentrations of glucose for 72 hours. Nkx2.5 immunofluorescent staining (red) was performed on the cultured cells. All of the cultured cells were counterstained with DAPI (blue). A-C: The representative bright-field images of the cells from the 5.5-mmol/l (A), 25-mmol/l (B) and 50-mmol/l (C) groups at 72 hours of incubation. A1-C1: The representative Nkx2.5 immunofluorescent staining images from the 5.5-mmol/l (A1), 25-mmol/l (B1) and 50-mmol/l (C1) groups. A2-C2: A1-C1 + DAPI counterstain. D: The bar charts showing the percentages of Nkx2.5+ cells/DAPI+ cells in the 5.5-mmol/l, 25-mmol/l and 50-mmol/l groups. E: Western blot data showing Nkx2.5 expression at the protein level in the 5.5-mmol/l, 25-mmol/l and 50-mmol/l groups. F: RT-PCR data showing the mRNA level of KCNE1 and Cx43 in the 5.5-mmol/l, 25-mmol/l and 50-mmol/l groups. *P<0.05 vs control. Scale bars: 100 μm in A-C, A1-C2.
Mentions: H9c2 cells that were exposed to a variety of concentrations of glucose in vitro were used to determine the effect of the expression of Nkx2.5 and its downstream genes in regulating heart formation (Fig 9A–9C). Nkx2.5 immunofluorescent staining showed that the percentage of Nkx2.5+ cell number/total cell number (DAPI+ cells) in the 50-mmol/l group (15.40±11.36%, n = 4) was significantly less than that in the 5.5-mmol/l (control) group (33.79±5.96%, n = 4; P<0.05), suggesting that high glucose (50 mmol/l) exposure suppressed the expression of Nkx2.5 compared to that of the control (5.5 mmol/l). Furthermore, western blotting data also indicated the same inhibitive tendency for Nkx2.5 expression at the protein level (Fig 9E). Meanwhile, we detected the expressions of KCNE1 and Cx43, the genes downstream of Nkx2.5, and the RT-PCR data showed that these genes were down-regulated simultaneously (Fig 9F), indicating that the expression of KCNE1 and Cx43 was affected by the down-regulation of Nkx2.5 induced by the high glucose level in PGDM.

Bottom Line: Next, we found that the individual cardiomyocyte size increased in pre-gestational diabetes mellitus mice and in response to high glucose exposure.Meanwhile, the expression of β-MHC and BMP-10 was up-regulated.In cultured H9c2 cells exposed to high glucose, Nkx2.5 expression decreased, as detected by both immunostaining and western blotting, and the expression of KCNE1 and Cx43 was also restricted.

View Article: PubMed Central - PubMed

Affiliation: Department of Pediatrics and Neonatology, Institute of Fetal-Preterm Labor Medicine, The First Affiliated Hospital, Jinan University, Guangzhou, 510630, China.

ABSTRACT
Hyperglycemia in diabetic mothers enhances the risk of fetal cardiac hypertrophy during gestation. However, the mechanism of high-glucose-induced cardiac hypertrophy is not largely understood. In this study, we first demonstrated that the incidence rate of cardiac hypertrophy dramatically increased in fetuses of diabetic mothers using color ultrasound examination. In addition, human fetal cardiac hypertrophy was successfully mimicked in a streptozotocin (STZ)-induced diabetes mouse model, in which mouse cardiac hypertrophy was diagnosed using type-M ultrasound and a histological assay. PH3 immunofluorescent staining of mouse fetal hearts and in vitro-cultured H9c2 cells indicated that cell proliferation decreased in E18.5, E15.5 and E13.5 mice, and cell apoptosis in H9c2 cells increased in the presence of high glucose in a dose-dependent manner. Next, we found that the individual cardiomyocyte size increased in pre-gestational diabetes mellitus mice and in response to high glucose exposure. Meanwhile, the expression of β-MHC and BMP-10 was up-regulated. Nkx2.5 immunofluorescent staining showed that the expression of Nkx2.5, a crucial cardiac transcription factor, was suppressed in the ventricular septum, left ventricular wall and right ventricular wall of E18.5, E15.5 and E13.5 mouse hearts. However, cardiac hypertrophy did not morphologically occur in E13.5 mouse hearts. In cultured H9c2 cells exposed to high glucose, Nkx2.5 expression decreased, as detected by both immunostaining and western blotting, and the expression of KCNE1 and Cx43 was also restricted. Taken together, alterations in cell size rather than cell proliferation or apoptosis are responsible for hyperglycemia-induced fetal cardiac hypertrophy. The aberrant expression of Nkx2.5 and its regulatory target genes in the presence of high glucose could be a principal component of pathogenesis in the development of fetal cardiac hypertrophy.

No MeSH data available.


Related in: MedlinePlus