TY - JOUR
T1 - Neuroendocrine phenotypes in a boy with 5q14 deletion syndrome implicate the regulatory roles of myocyte-specific enhancer factor 2C in the postnatal hypothalamus
AU - Sakai, Yasunari
AU - Ohkubo, Kazuhiro
AU - Matsushita, Yuki
AU - Akamine, Satoshi
AU - Ishizaki, Yoshito
AU - Torisu, Hiroyuki
AU - Ihara, Kenji
AU - Sanefuji, Masafumi
AU - Kim, Min Seon
AU - Lee, Ki Up
AU - Shaw, Chad A.
AU - Lim, Janghoo
AU - Nakabeppu, Yusaku
AU - Hara, Toshiro
N1 - Funding Information:
This study was supported by JSPS KAKENHI (#24650199 and 23810025 to Y.S. and #22221004 to Y.N.), the Life Science Foundation of Japan (Y.S.), the Takeda Science Foundation, Japan (Y.S.), the Yale Scholar Award Program (J.L.) and the NARSAD Young Investigator Grant and the Charles H. Hood Foundation (J.L.).
PY - 2013/9
Y1 - 2013/9
N2 - The 5q14.3 deletion syndrome is a rare chromosomal disorder characterized by moderate to severe intellectual disability, seizures and dysmorphic features. We report a 14-year-old boy with 5q14.3 deletion syndrome who carried a heterozygous deletion of the myocyte-specific enhancer factor 2c (MEF2C) gene. In addition to the typical neurodevelopmental features of 5q14.3 deletion syndrome, he showed recurrent hypoglycemia, appetite loss and hypothermia. Hormonal loading tests using insulin, arginine and growth hormone-releasing factor revealed that growth hormone was insufficiently released into serum in response to these stimuli, thus disclosing the hypothalamic dysfunction in the present case. To uncover the biological roles of MEF2C in the hypothalamus, we studied its expression in the postnatal mouse brain. Notably, neuropeptide Y (NPY)-positive interneurons in the hypothalamic arcuate nuclei highly expressed MEF2C. In contrast, the Rett syndrome-associated protein, Methyl-CpG binding Protein 2 (MECP2) was barely expressed in these neurons. MEF2C knockdown or overexpression experiments using Neuro2a cells revealed that MEF2C activated the endogenous transcription of NPY. Conversely, siRNA-mediated knockdown of MECP2 led to derepression of the Npy gene. These data support the concept that MEF2C and MECP2 share common molecular pathways regulating the homeostatic expression of NPY in the adult hypothalamus. We propose that individuals with 5q14.3 deletion syndrome may exhibit neuroendocrine phenotypes through the functional loss of MEF2C in the postnatal hypothalamus.
AB - The 5q14.3 deletion syndrome is a rare chromosomal disorder characterized by moderate to severe intellectual disability, seizures and dysmorphic features. We report a 14-year-old boy with 5q14.3 deletion syndrome who carried a heterozygous deletion of the myocyte-specific enhancer factor 2c (MEF2C) gene. In addition to the typical neurodevelopmental features of 5q14.3 deletion syndrome, he showed recurrent hypoglycemia, appetite loss and hypothermia. Hormonal loading tests using insulin, arginine and growth hormone-releasing factor revealed that growth hormone was insufficiently released into serum in response to these stimuli, thus disclosing the hypothalamic dysfunction in the present case. To uncover the biological roles of MEF2C in the hypothalamus, we studied its expression in the postnatal mouse brain. Notably, neuropeptide Y (NPY)-positive interneurons in the hypothalamic arcuate nuclei highly expressed MEF2C. In contrast, the Rett syndrome-associated protein, Methyl-CpG binding Protein 2 (MECP2) was barely expressed in these neurons. MEF2C knockdown or overexpression experiments using Neuro2a cells revealed that MEF2C activated the endogenous transcription of NPY. Conversely, siRNA-mediated knockdown of MECP2 led to derepression of the Npy gene. These data support the concept that MEF2C and MECP2 share common molecular pathways regulating the homeostatic expression of NPY in the adult hypothalamus. We propose that individuals with 5q14.3 deletion syndrome may exhibit neuroendocrine phenotypes through the functional loss of MEF2C in the postnatal hypothalamus.
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U2 - 10.1016/j.ejmg.2013.06.009
DO - 10.1016/j.ejmg.2013.06.009
M3 - Article
C2 - 23832106
AN - SCOPUS:84884175203
VL - 56
SP - 475
EP - 483
JO - European Journal of Medical Genetics
JF - European Journal of Medical Genetics
SN - 1769-7212
IS - 9
ER -