Read by QxMD icon Read


Bin Guan, James M Welch, Julie C Sapp, Hua Ling, Yulong Li, Jennifer J Johnston, Electron Kebebew, Leslie G Biesecker, William F Simonds, Stephen J Marx, Sunita K Agarwal
Primary hyperparathyroidism (PHPT) is a common endocrine disease characterized by parathyroid hormone excess and hypercalcemia and caused by hypersecreting parathyroid glands. Familial PHPT occurs in an isolated nonsyndromal form, termed familial isolated hyperparathyroidism (FIHP), or as part of a syndrome, such as multiple endocrine neoplasia type 1 or hyperparathyroidism-jaw tumor syndrome. The specific genetic or other cause(s) of FIHP are unknown. We performed exome sequencing on germline DNA of eight index-case individuals from eight unrelated kindreds with FIHP...
October 13, 2016: American Journal of Human Genetics
Geoffrey N Hendy, Lucie Canaff
The human calcium-sensing receptor gene (CASR) has 8 exons, and localizes to chromosome 3q. Exons 1A and 1B encode alternative 5'-untranslated regions (UTRs) that splice to exon 2 encoding the AUG initiation codon. Exons 2-7 encode the CaSR protein of 1078 amino acids. Promoter P1 has TATA and CCAAT boxes upstream of exon 1A, and promoter P2 has Sp1/3 motifs at the start site of exon 1B. Exon 1A transcripts from the P1 promoter are reduced in parathyroid tumors and colon carcinomas. Studies of colon carcinomas and neuroblastomas have emphasized the importance of epigenetic changes-promoter methylation of the GC-rich P2 promoter, histone acetylation-as well as involvement of microRNAs in bringing about CASR gene silencing and reduced CaSR expression...
2016: Frontiers in Physiology
Virginia E Bain, Julie Gordon, John D O'Neil, Isaias Ramos, Ellen R Richie, Nancy R Manley
The thymus and parathyroids develop from shared organ primordia derived from third pharyngeal pouch (3(rd) pp) endoderm. Our previous studies show that Sonic hedgehog (Shh) null mutants have smaller, aparathyroid primordia in which thymus fate specification extends into the pharynx. SHH signaling is active in both dorsal pouch endoderm and neighboring neural crest mesenchyme, but it is unclear which target tissue of SHH signaling is required for the patterning defects seen in Shh mutants. We have taken a genetic approach to this question by ectopically activating or deleting the SHH signal transducer Smoothened (Smo) in either pharyngeal pouch endoderm or neural crest (NC) mesenchyme...
September 15, 2016: Development
Marta Figueiredo, Joana Clara Silva, Ana Sofia Santos, Vitor Proa, Isabel Alcobia, Rita Zilhão, António Cidadão, Hélia Neves
The avian thymus and parathyroids (T/PT) common primordium derives from the endoderm of the third and fourth pharyngeal pouches (3/4PP). The molecular mechanisms that govern T/PT development are not fully understood. Here we study the effects of Notch and Hedgehog (Hh) signalling modulation during common primordium development using in vitro, in vivo and in ovo approaches. The impairment of Notch activity reduced Foxn1/thymus-fated and Gcm2/Pth/parathyroid-fated domains in the 3/4PP and further compromised the development of the parathyroid glands...
October 15, 2016: Developmental Biology
Yueh Ho Chiu, Hungwen Chen
Development of human placenta involves the invasion of trophoblast cells from anchoring villi into the maternal decidua. Placental transcription factor GCM1 regulates trophoblast cell invasion via transcriptional activation of HtrA4 gene, which encodes a serine protease enzyme. The GATA3 transcription factor regulates trophoblast cell differentiation and is highly expressed in invasive murine trophoblast giant cells. The regulation of trophoblastic invasion by GCM1 may involve novel cellular factors. Here we show that GATA3 interacts with GCM1 and inhibits its activity to suppress trophoblastic invasion...
2016: Scientific Reports
Chia-Hao Lin, Huei-Jyun Hu, Pung-Pung Hwang
In mammals, sodium/hydrogen exchanger (NHE) and sodium-chloride cotransporter (NCC) are expressed in renal tubules, and exhibit functional redundancy and mutual compensation in Na(+) uptake. In teleosts, the gills of the adult and skin of the embryonic stage function as external kidneys, and ionocytes are responsible for ionoregulation in these tissues. NHE- and NCC-expressing ionocytes mutually cooperate to adjust Na(+) uptake, which is analogous to the activity of the mammalian kidney. Cortisol is a hormone that controls Na(+) uptake through regulating NCC expression and activity in mammals; however, cortisol-mediated control of NCC expression is little understood in non-mammalian vertebrates, such as teleosts...
February 15, 2016: Molecular and Cellular Endocrinology
Vincent Trayer, Nina Séjourné, Stéphanie Gay, Violette Thermes
BACKGROUND: The fish epidermis contains specific cells, or ionocytes, that are specialized in ion transport and contribute to the osmoregulatory function. Besides the zebrafish model, the medaka (Oryzias latipes) has recently emerged as an important model for osmoregulation studies because it possesses a particularly high adaptability to salinity changes. However, hindering the progress of research on embryonic ionocytes is the lack of a comprehensive view of their developmental dynamic...
July 2015: Developmental Dynamics: An Official Publication of the American Association of Anatomists
Song-Iee Han, Yukino Tsunekage, Kohsuke Kataoka
Haploinsufficiency of the Gata3 gene, which encodes a zinc-finger transcription factor, is associated with the disorder hypoparathyroidism, deafness, and renal dysplasia (HDR) syndrome in humans. However, the roles of Gata3 in transcriptional regulation in the parathyroid glands are not well-understood. In this study, we show that Gata3 activates transcription of parathyroid hormone (PTH), which is secreted from parathyroid glands and is critical for regulating serum calcium and phosphate homeostasis. Gata3 interacted with Gcm2 and MafB, two known transcriptional regulators of parathyroid development, and synergistically stimulated the PTH promoter...
August 15, 2015: Molecular and Cellular Endocrinology
Raymond W M Kwong, Steve F Perry
In vertebrates, parathyroid hormone (PTH) is important for skeletogenesis and Ca(2+) homeostasis. However, little is known about the molecular mechanisms by which PTH regulates skeleton formation and Ca(2+) balance during early development. Using larval zebrafish as an in vivo model system, we determined that PTH1 regulates the differentiation of epithelial cells and the development of craniofacial cartilage. We demonstrated that translational gene knockdown of PTH1 decreased Ca(2+) uptake at 4 days after fertilization...
July 2015: Endocrinology
Leonardo D'Agruma, Michela Coco, Vito Guarnieri, Claudia Battista, Lucie Canaff, Antonio S Salcuni, Sabrina Corbetta, Filomena Cetani, Salvatore Minisola, Iacopo Chiodini, Cristina Eller-Vainicher, Anna Spada, Claudio Marcocci, Giuseppe Guglielmi, Michele Zini, Rosanna Clemente, Betty Y L Wong, Danilo de Martino, Alfredo Scillitani, Geoffrey N Hendy, David E C Cole
CONTEXT: Glial cells missing-2 (GCM2) is key for parathyroid gland organogenesis. Its persistent expression in the adult parathyroid raises the possibility that overactive forms play a role in the evolution of parathyroid hyperactivity or tumorigenesis. A GCM2 c.844T → G; p.Y282D missense variant has been described within a transactivation inhibitory domain (amino acids 263-352). OBJECTIVE: The aims of the study were to 1) assess the frequency of Y282D in Italian primary hyperparathyroidism (PHPT) and control (C) populations, 2) test for association of 282D with PHPT and its phenotypic features, and 3) compare the transactivation potency of GCM2 282D relative to wild-type Y282...
December 2014: Journal of Clinical Endocrinology and Metabolism
Jena L Chojnowski, Kyoko Masuda, Heidi A Trau, Kirk Thomas, Mario Capecchi, Nancy R Manley
Hoxa3 was the first Hox gene to be mutated by gene targeting in mice and is required for the development of multiple endoderm and neural crest cell (NCC)-derived structures in the pharyngeal region. Previous studies have shown that the Hoxa3 null mutant lacks third pharyngeal pouch derivatives, the thymus and parathyroids by E18.5, and organ-specific markers are absent or downregulated during initial organogenesis. Our current analysis of the Hoxa3 null mutant shows that organ-specific domains did undergo initial patterning, but the location and timing of key regional markers within the pouch, including Tbx1, Bmp4 and Fgf8, were altered...
October 2014: Development
Toshikatsu Mitsui, Satoshi Narumi, Mikako Inokuchi, Keisuke Nagasaki, Mie Nakazawa, Goro Sasaki, Tomonobu Hasegawa
CONTEXT: In most patients with hypoparathyroidism (HP), the etiology is not defined clinically. Eight genes (AIRE, CASR, CLDN16, GATA3, GCM2, PTH, TBCE, and TRPM6) are known to be responsible genes associated with HP; however, no previous study has screened the eight responsible genes comprehensively in HP patients. OBJECTIVES: This study was conducted to determine the genetic defect in HP patients. We also described clinical and molecular findings of two HP patients with novel GCM2 mutations...
November 2014: Journal of Clinical Endocrinology and Metabolism
Kaitlin A G Reeh, Kim T Cardenas, Virginia E Bain, Zhijie Liu, Micheline Laurent, Nancy R Manley, Ellen R Richie
The thymus and parathyroid glands arise from a shared endodermal primordium in the third pharyngeal pouch (3rd pp). Thymus fate is specified in the ventral 3rd pp between E9.5 and E11, whereas parathyroid fate is specified in the dorsal domain. The molecular mechanisms that specify fate and regulate thymus and parathyroid development are not fully delineated. Previous reports suggested that Tbx1 is required for thymus organogenesis because loss of Tbx1 in individuals with DiGeorge syndrome and in experimental Tbx1 deletion mutants is associated with thymus aplasia or hypoplasia...
August 2014: Development
Tamara M Stawicki, Kelly N Owens, Tor Linbo, Katherine E Reinhart, Edwin W Rubel, David W Raible
Control of the extracellular environment of inner ear hair cells by ionic transporters is crucial for hair cell function. In addition to inner ear hair cells, aquatic vertebrates have hair cells on the surface of their body in the lateral line system. The ionic environment of these cells also appears to be regulated, although the mechanisms of this regulation are less understood than those of the mammalian inner ear. We identified the merovingian mutant through genetic screening in zebrafish for genes involved in drug-induced hair cell death...
July 2014: Disease Models & Mechanisms
Yusuke Kumai, Cosima S Porteus, Raymond W M Kwong, Steve F Perry
The present study investigated the role of hydrogen sulfide (H2S) in regulating Na(+) uptake in larval zebrafish, Danio rerio. Waterborne treatment of larvae at 4 days post-fertilization (dpf) with Na2S or GYY-4137 (chemicals known to generate H2S) significantly reduced Na(+) uptake. Exposure of larvae to water enriched with NaCl (1 mM NaCl) caused a pronounced reduction in Na(+) uptake which was prevented by pharmacological inhibition of cystathionine β-synthase (CBS) or cystathionine γ-lyase (CSE), two key enzymes involved in the endogenous synthesis of H2S...
April 2015: Pflügers Archiv: European Journal of Physiology
Yusuke Kumai, Raymond W M Kwong, Steve F Perry
The present study investigated the role of the transcription factor, glial cell missing 2 (gcm2), in Ca(2+) regulation in zebrafish larvae. Translational gene knockdown of gcm2 decreased Ca(2+) uptake and the density of ionocytes expressing the epithelial Ca(2+) channel (ecac), and disrupted the overall Ca(2+) balance. Ca(2+) uptake and the expression of gcm2 messenger RNA (mRNA) were significantly elevated in larvae acclimated to low Ca(2+) water (25 μM); the stimulation of Ca(2+) uptake was not observed in fish experiencing gcm2 knockdown...
April 2015: Pflügers Archiv: European Journal of Physiology
Dong Li, Evan E Opas, Florin Tuluc, Daniel L Metzger, Cuiping Hou, Hakon Hakonarson, Michael A Levine
CONTEXT: Most cases of autosomal dominant hypoparathyroidism (ADH) are caused by gain-of-function mutations in CASR or dominant inhibitor mutations in GCM2 or PTH. OBJECTIVE: Our objectives were to identify the genetic basis for ADH in a multigenerational family and define the underlying disease mechanism. SUBJECTS: Here we evaluated a multigenerational family with ADH in which affected subjects had normal sequences in these genes and were shorter than unaffected family members...
September 2014: Journal of Clinical Endocrinology and Metabolism
Ziqiang Yuan, Evan E Opas, Chakravarthy Vrikshajanani, Steven K Libutti, Michael A Levine
Glial cells missing homolog 2 (GCM2) is a transcription factor that is expressed predominately in the pharyngeal pouches and, at later stages, in the developing and mature parathyroid glands. In humans, loss of GCM2 function, either through recessive apomorphic mutations or dominant inhibitor mutations in the human GCM2 gene, leads to isolated hypoparathyroidism. In mice, homozygous disruption of Gcm2 by conventional gene targeting results in parathyroid aplasia and hypoparathyroidism. In this study, we report the generation and functional characterization of mice encoding a conditional null allele of Gcm2...
August 2014: Transgenic Research
Valentin David, Bing Dai, Aline Martin, Jinsong Huang, Xiaobin Han, L Darryl Quarles
Calcium has recently been shown to regulate fibroblast growth factor 23 (FGF-23), a bone-derived phosphate and vitamin D-regulating hormone. To better understand the regulation of FGF-23 by calcium, phosphorus, 1,25 dihydroxyvitamin D3 [1,25(OH)2D], and PTH, we examined FGF-23 expression under basal conditions and in response to PTH, doxercalciferol, or high-calcium diet treatment in Gcm2(-/-) and Cyp27b1(-/-) mutant mice. Gcm2(-/-) mice exhibited low serum PTH and 1,25(OH)2D concentrations, hypocalcemia, and hyperphosphatemia, whereas Cyp27b1(-/-) mice had high PTH, undetectable 1,25(OH)2D, hypocalcemia, and hypophosphatemia...
December 2013: Endocrinology
Christopher J Ricketts, Mark R Morris, Dean Gentle, Salwati Shuib, Michael Brown, Noel Clarke, Wenbin Wei, Paul Nathan, Farida Latif, Eamonn R Maher
BACKGROUND: Despite therapeutic advances in targeted therapy, metastatic renal cell carcinoma (RCC) remains incurable for the vast majority of patients. Key molecular events in the pathogenesis of RCC include inactivation of the VHL tumour suppressor gene (TSG), inactivation of chromosome 3p TSGs implicated in chromatin modification and remodelling and de novo tumour-specific promoter methylation of renal TSGs. In the light of these observations it can be proposed that, as in some haematological malignancies, demethylating agents such as azacitidine might be beneficial for the treatment of advanced RCC...
2013: Clinical Epigenetics
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"