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Hyperglycemia: GDNF-EGR1 pathway target renal epithelial cell migration and apoptosis in diabetic renal embryopathy.

Lin CY, Lin TY, Lee MC, Chen SC, Chang JS - PLoS ONE (2013)

Bottom Line: Preliminary study found EGR-1 persistently expressed with GDNF in hyperglycemic environment.EGR-1 siRNA also reduced GDNF/EGR-1-induced cRaf/MEK/ERK phosphorylation by 80%.Our findings reveal a novel mechanism of GDNF/MAPK/EGR-1 activation playing a critical role in HRPTE cell migration, apoptosis and fetal hyperglycemic nephropathy.

View Article: PubMed Central - PubMed

Affiliation: Clinical Immunology Center, China Medical University Hospital, Taichung, Taiwan. cylin@mail.cmuh.org.tw

ABSTRACT
Maternal hyperglycemia can inhibit morphogenesis of ureteric bud branching, Glial cell line-derived neurotrophilic factor (GDNF) is a key regulator of the initiation of ureteric branching. Early growth response gene-1 (EGR-1) is an immediate early gene. Preliminary study found EGR-1 persistently expressed with GDNF in hyperglycemic environment. To evaluate the potential relationship of hyperglycemia-GDNF-EGR-1 pathway, in vitro human renal proximal tubular epithelial (HRPTE) cells as target and in vivo streptozotocin-induced mice model were used. Our in vivo microarray, real time-PCR and confocal morphological observation confirmed apoptosis in hyperglycemia-induced fetal nephropathy via activation of the GDNF/MAPK/EGR-1 pathway at E12-E15. Detachment between ureteric branch and metanephrons, coupled with decreasing number and collapse of nephrons on Day 1 newborn mice indicate hyperglycemic environment suppress ureteric bud to invade metanephric rudiment. In vitro evidence proved that high glucose suppressed HRPTE cell migration and enhanced GDNF-EGR-1 pathway, inducing HRPTE cell apoptosis. Knockdown of EGR-1 by siRNA negated hyperglycemic suppressed GDNF-induced HRPTE cells. EGR-1 siRNA also reduced GDNF/EGR-1-induced cRaf/MEK/ERK phosphorylation by 80%. Our findings reveal a novel mechanism of GDNF/MAPK/EGR-1 activation playing a critical role in HRPTE cell migration, apoptosis and fetal hyperglycemic nephropathy.

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Serial gene expression patterns from E11 to E15 of fetal renal tissue.Measurement of serial GDNF, EGR-1, Ras, Raf, MEK and ERK gene expression by quantitative renal time PCR (qPCR) on cDNA from E11 to E15 of fetal renal tissue, either in hyperglycemic or normoglycemic state. Change pattern was very similar in these genes, all of them highly expressed at E12, dramatically dropping at E13, then progressively increasing from E14 to E15. (Fig. 2a. GDNF, 2b. EGR-1, 2c. Ras, 2d. Raf, 2e. MEK, 2f. ERK, and summary 2 g; n = 10).
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pone-0056731-g002: Serial gene expression patterns from E11 to E15 of fetal renal tissue.Measurement of serial GDNF, EGR-1, Ras, Raf, MEK and ERK gene expression by quantitative renal time PCR (qPCR) on cDNA from E11 to E15 of fetal renal tissue, either in hyperglycemic or normoglycemic state. Change pattern was very similar in these genes, all of them highly expressed at E12, dramatically dropping at E13, then progressively increasing from E14 to E15. (Fig. 2a. GDNF, 2b. EGR-1, 2c. Ras, 2d. Raf, 2e. MEK, 2f. ERK, and summary 2 g; n = 10).

Mentions: To confirm GDNF, EGR-1, Ras, cRaf, MEK and ERK mRNA expression differing significantly between hyperglycemic and normoglycemic fetal kidney tissues observed using microarray analysis, we performed quantitative RT-PCR and compared expression patterns, as shown in Figs.2a, b, c, d, e, f, g. We found that GDNF, EGR-1, Ras, cRaf, MEK and ERK gene expression differed between hyperglycemic and normoglycemic fetal kidney tissue. Change patterns were similar in these genes, all highly expressed at E12 and dramatically dropping at E13, then progressively rising in E14–E15, (Figs.1a, b, c, d, e, f). Figure 2c shows Ras differently expressed: it reached at least 3.2 fold elevated ratio in hyperglycemic fetal kidney tissues compared to normoglycemic ones at E12 in each of ten samples (p<0.01), decreasing rapidly at E13 and progressively returning to E11 range at E15.


Hyperglycemia: GDNF-EGR1 pathway target renal epithelial cell migration and apoptosis in diabetic renal embryopathy.

Lin CY, Lin TY, Lee MC, Chen SC, Chang JS - PLoS ONE (2013)

Serial gene expression patterns from E11 to E15 of fetal renal tissue.Measurement of serial GDNF, EGR-1, Ras, Raf, MEK and ERK gene expression by quantitative renal time PCR (qPCR) on cDNA from E11 to E15 of fetal renal tissue, either in hyperglycemic or normoglycemic state. Change pattern was very similar in these genes, all of them highly expressed at E12, dramatically dropping at E13, then progressively increasing from E14 to E15. (Fig. 2a. GDNF, 2b. EGR-1, 2c. Ras, 2d. Raf, 2e. MEK, 2f. ERK, and summary 2 g; n = 10).
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3585314&req=5

pone-0056731-g002: Serial gene expression patterns from E11 to E15 of fetal renal tissue.Measurement of serial GDNF, EGR-1, Ras, Raf, MEK and ERK gene expression by quantitative renal time PCR (qPCR) on cDNA from E11 to E15 of fetal renal tissue, either in hyperglycemic or normoglycemic state. Change pattern was very similar in these genes, all of them highly expressed at E12, dramatically dropping at E13, then progressively increasing from E14 to E15. (Fig. 2a. GDNF, 2b. EGR-1, 2c. Ras, 2d. Raf, 2e. MEK, 2f. ERK, and summary 2 g; n = 10).
Mentions: To confirm GDNF, EGR-1, Ras, cRaf, MEK and ERK mRNA expression differing significantly between hyperglycemic and normoglycemic fetal kidney tissues observed using microarray analysis, we performed quantitative RT-PCR and compared expression patterns, as shown in Figs.2a, b, c, d, e, f, g. We found that GDNF, EGR-1, Ras, cRaf, MEK and ERK gene expression differed between hyperglycemic and normoglycemic fetal kidney tissue. Change patterns were similar in these genes, all highly expressed at E12 and dramatically dropping at E13, then progressively rising in E14–E15, (Figs.1a, b, c, d, e, f). Figure 2c shows Ras differently expressed: it reached at least 3.2 fold elevated ratio in hyperglycemic fetal kidney tissues compared to normoglycemic ones at E12 in each of ten samples (p<0.01), decreasing rapidly at E13 and progressively returning to E11 range at E15.

Bottom Line: Preliminary study found EGR-1 persistently expressed with GDNF in hyperglycemic environment.EGR-1 siRNA also reduced GDNF/EGR-1-induced cRaf/MEK/ERK phosphorylation by 80%.Our findings reveal a novel mechanism of GDNF/MAPK/EGR-1 activation playing a critical role in HRPTE cell migration, apoptosis and fetal hyperglycemic nephropathy.

View Article: PubMed Central - PubMed

Affiliation: Clinical Immunology Center, China Medical University Hospital, Taichung, Taiwan. cylin@mail.cmuh.org.tw

ABSTRACT
Maternal hyperglycemia can inhibit morphogenesis of ureteric bud branching, Glial cell line-derived neurotrophilic factor (GDNF) is a key regulator of the initiation of ureteric branching. Early growth response gene-1 (EGR-1) is an immediate early gene. Preliminary study found EGR-1 persistently expressed with GDNF in hyperglycemic environment. To evaluate the potential relationship of hyperglycemia-GDNF-EGR-1 pathway, in vitro human renal proximal tubular epithelial (HRPTE) cells as target and in vivo streptozotocin-induced mice model were used. Our in vivo microarray, real time-PCR and confocal morphological observation confirmed apoptosis in hyperglycemia-induced fetal nephropathy via activation of the GDNF/MAPK/EGR-1 pathway at E12-E15. Detachment between ureteric branch and metanephrons, coupled with decreasing number and collapse of nephrons on Day 1 newborn mice indicate hyperglycemic environment suppress ureteric bud to invade metanephric rudiment. In vitro evidence proved that high glucose suppressed HRPTE cell migration and enhanced GDNF-EGR-1 pathway, inducing HRPTE cell apoptosis. Knockdown of EGR-1 by siRNA negated hyperglycemic suppressed GDNF-induced HRPTE cells. EGR-1 siRNA also reduced GDNF/EGR-1-induced cRaf/MEK/ERK phosphorylation by 80%. Our findings reveal a novel mechanism of GDNF/MAPK/EGR-1 activation playing a critical role in HRPTE cell migration, apoptosis and fetal hyperglycemic nephropathy.

Show MeSH
Related in: MedlinePlus