OBJECTIVE: To identify the miRNAs targeting vitamin D receptor (VDR) gene and their effect on parathyroid hormone (PTH) secretion in secondary hyperparathyroidism. METHODS: Primary parathyroid cells with secondary hyperparathyroidism were isolated by collagenase digestion and cultured. The miRNAs targeting VDR were screened by bioinformatics methods and full transcriptome sequencing, and dual-luciferase reporter assay was used to verify the targeting relationship between VDR and the screened miRNA. The effects of overexpression or inhibition of the candidate miRNA on VDR mRNA and protein expressions and PTH secretion were evaluated using qRT-PCR and Western blotting. The expression levels of the candidate miRNAs and VDR mRNA in clinical specimens of parathyroid tissues were verified by qRT-PCR, and the expression of VDR protein was detected by immunohistochemistry. RESULTS: We successfully isolated primary parathyroid cells. Dual-luciferase reporter assay verified the targeting relationship of hsa-miR-149-5p, hsa-miR-221-5p, hsa-miR-222-3p, hsa-miR-29a-5p, hsa-miR-301a-5p, hsa-miR-873-5p, hsa-miR-93-3p with VDR, and among them, the overexpression of hsa-miR-149-5p and hsa-miR-301a-5p significantly increased PTH secretion in the parathyroid cells. In patients with secondary hyperparathyroidism, hsa-miR-149-5p was highly expressed in the parathyroid tissues (P=0.046), where the expressions of VDR mRNA (P=0.0267) and protein were both decreased. CONCLUSION The two miRNAs, hsa-miR-149-5p and hsa-miR-301a-5p, may promote the secretion of PTH in patients with secondary hyperparathyroidism by down-regulating the expression of VDR gene.
Humans ; Hyperparathyroidism, Secondary/genetics* ; MicroRNAs/metabolism* ; Parathyroid Hormone ; RNA, Messenger ; Receptors, Calcitriol/genetics*

OBJECTIVE: To explore the genetic basis for a child with neonatal severe hyperparathyroidism. METHODS: Genomic DNA was extracted from peripheral blood samples from the patient and her parents. Whole exome sequencing was carried out to screen potential mutations. Suspected mutation was verified by Sanger sequencing. RESULTS: The proband was found to carry compound heterozygous variants c.179G>A (p.Cys60Tyr) and c.1525G>A (p.Gly509Arg) of the CaSR gene. The c.179G>A variant was derived from her mother and was unreported previously. The c.1525G>A variant was derived from her father and known to be pathogenic. CONCLUSION The compound heterozygous variants of c.179G>A and c.1525G>A of the CaSR gene probably underlie the disease in the patient. The results of genetic testing has enabled diagnosis and genetic counseling for her family.
Female ; Genetic Counseling ; Genetic Testing ; Humans ; Hyperparathyroidism/genetics* ; Infant, Newborn ; Infant, Newborn, Diseases/genetics* ; Mutation ; Pedigree ; Receptors, Calcium-Sensing/genetics* ; Whole Exome Sequencing

Adult ; Aged ; Female ; Humans ; Hyperparathyroidism, Secondary ; metabolism ; pathology ; Immunohistochemistry ; Male ; Middle Aged ; Parathyroid Glands ; chemistry ; RNA, Messenger ; analysis ; Receptors, Calcium-Sensing ; analysis ; genetics ; Uremia ; metabolism

BACKGROUNDHyperphosphatemia in renal failure has been identified as a major role in the pathogenesis of hyperparathyroidism that is independent of changes in serum calcium and 1,25(OH)(2)D(3). The aim of this study was to evaluate the expression of parathyroid Pit-1 in hyperphosphatemia-induced secondary hyperparathyroidism (SHPT) of chronic renal failure (CRF) rats.

METHODSWistar rats with CRF induced by 5/6 nephrectomy were ramdomly fed with diet containing 1.2% inorganic phosphate (Pi, high phosphate (HP) group, n = 9) or 0.2% Pi (low phosphate (LP) group, n = 9) for 10 weeks starting from the fourth week after the surgery. Another 7 nephrectomy rats with HP diet were intraperitoneally injected with phosphonoformic acid (PFA, the specific inhibitor of Pit-1, HP + PFA group) 0.15 g/kg every other day for 10 weeks starting from HP diet. Another 6 HP rats injected with the same amount of normal saline as the control of the HP + PFA group (HP + saline group). At the same time, 9 rats with sham surgery received HP diet as the controls. At the 4th week and 14th week, blood was taken for measurement of serum creatinine (SCr), serum calcium (SCa), serum phosphorus (SPi), 1,25(OH)(2)D(3) and intact parathyroid hormone (iPTH). At the 14th week, two parathroid glands (PTGs) of each rat were removed by microsurgery, one gland for immunohistochemistry analysis of proliferating cell nuclear antigen (PCNA), the other one for detection of Pit-1 by Western blotting, and for the measurement of Pit-1 mRNA and PTH mRNA by real-time quantitative polymerase chain reaction.

RESULTSIn nephrectomy rats, high dierary phosphate induced a marked increase in serum phosphate, iPTH, PTH mRNA and PCNA parathyroid cells, accompanying Pit-1 and its mRNA in parathyroid gland increased significantly. However, serum Ca and 1,25(OH)(2)D(3) remained unchanged. PFA decreased Pit-1 and its mRNA levels to reduce intact PTH, PTH mRNA and PCNA-positive parathyroid cells.

CONCLUSIONSExpression of parathyroid Pit-1 in hyperphosphatemia-induced SHPT of CRF rats was upregulated. Pit-1 may mediate the stimulation to parathyroid gland by hyperphosphatemia.

Animals ; Blotting, Western ; Hyperparathyroidism, Secondary ; etiology ; metabolism ; Hyperphosphatemia ; complications ; Immunohistochemistry ; Kidney Failure, Chronic ; complications ; Male ; Polymerase Chain Reaction ; Rats ; Rats, Wistar ; Sodium-Phosphate Cotransporter Proteins, Type III ; genetics ; metabolism

Multiple endocrine neoplasia type 1 (MEN1) syndrome includes varying combinations of endocrine and non-endocrine tumors. There are also a considerable number of atypical MEN1 syndrome. In this case, a 68-yr-old woman was referred to the Department of Endocrinology for hypercalcemia. Five years ago, she had diagnosed as primary hyperaldosteronism and now newly diagnosed as parathyroid hyperplasia with laboratory and pathologic findings. Hurthle-cell thyroid cancer was also resected during the parathyroid exploration and small meningioma was found on brain MRI. Her general condition has markedly improved and her adrenal mass and meningioma are being closely observed now. We could find the loss of heterozygosity of the MEN1 locus in parathyroid glands, suggesting a MEN1-related tumor, but not a germline mutation. Considering a variety of phenotypic expression and a limitation of current molecular analysis, periodic follow up will be needed in patients with a MEN1-like phenotype.
Aged ; Base Sequence ; Brain/radionuclide imaging ; Female ; Humans ; Hyperaldosteronism/complications/*diagnosis ; Hyperparathyroidism, Primary/*diagnosis/etiology/pathology ; Loss of Heterozygosity ; Magnetic Resonance Imaging ; Meningeal Neoplasms/complications/*diagnosis/radionuclide imaging ; Meningioma/complications/*diagnosis/radionuclide imaging ; Mutation ; Parathyroid Glands/pathology ; Proto-Oncogene Proteins/genetics/metabolism ; Sequence Analysis, DNA ; Thyroid Neoplasms/complications/*diagnosis/pathology ; Tomography, X-Ray Computed