Project description:Studies on human parathyroid tissue are often limited to adenomatous tissue due to difficulty obtaining healthy tissue. We obtained nonhuman primate parathyroids to provide a suitable alternative for sequencing analysis that would bear the closest semblance to human organs as possible. We analyzed four M. mulatta normal parathyroid specimens to that show a continuous trajectory of cell states comprising the normal adult parathyroid. We calculated the predicted pseudotime progression based on transcriptomic signatures that were reflective of repopulating progenitors, progressing to chief cells, and ultimately oxyphils, and clustered genes based on their expression dynamics along this axis. As a comparator, we histologically characterized and sequenced four human adenomas with varying oxyphil and chief cell abundance to highlight similarities and differences to normal parathyroid cell expression dynamics. We noted abundant RARRES2 transcripts that were detected in both human adenoma and normal primate parathyroid cells, and provided co-immunostaining validation of Chemerin presence in PTH-expressing cells, which could play a previously unrecognized role in parathyroid endocrine function.
Project description:A investigation of the gene expression of one parathyroid tumour compared to its adjacent normal tissue Keywords: differentially expressed gene profile
Project description:Transcriptional profiling of genes expressed in normal parathyroid glands (Normal) and adenomatous parathyroid glands from patients with primary hyperparathyroidism (PHPT). Stratagen Human Refernece RNA, pooled from 10 human cell lines, was used to identify genes, which are specifically expressed or suppressed in parathyroid tissue. Comparison between normal and tumor parathyroids shows genes that might be involved in hyperproliferation and PTH hypersecretion in tumors.
Project description:The pathogenesis of primary hyperparathyroidism (I-HPT) and secondary hyperparathyroidism (II-PTH) remains to be elucidated. To characterize their pathophysiology, we investigated the effects of calcium and phosphate on cell proliferation and PTH release in an organ culture of parathyroid tissues. Dissected parathyroid tissues obtained from patients with I-HPT (adenoma) or II-PTH (nodular hyperplasia) were precultured on a collagen-coated membrane for 1-4 week. After exchanging the medium for one containing various concentrations of phosphate, PTH release and [3H]thymidine incorporation were studied. In contrast to dispersed parathyroid cells cultured in a monolayer, calcium decreased PTH release in a concentration-dependent manner in parathyroid tissues. Furthermore, when parathyroid tissues obtained from II-PTH were precultured for 1-4 weeks, PTH release and parathyroid cell proliferation were significantly increased in high-phosphate medium. These phosphate effects were also observed to a lesser extent in parathyroid tissues obtained from I-HPT, but there was no significant difference between I-HPT and II-HPT. Microarray analyses revealed that mRNA levels of PTH, CaSR, and VDR were well preserved, and several growth factors (e.g. TGF-beta1-induced protein) were abundantly expressed in II-PTH. Using organ cultures of hyperparathyroid tissues, in which PTH release and CaSR are well preserved for a prolonged period, we have demonstrated that phosphate stimulates parathyroid cell proliferation not only in II-PTH but also in I-HPT. Although the mechanism responsible for phosphate-induced cell proliferation remains to be elucidated, our in vitro findings suggest that both parathyroid tissues preserve to some extent a physiological response system to hyperphosphatemia as observed in normal parathyroid cells. These data will be published in Journal of Bone & Mineral Metabolism. Experiment Overall Design: Two conditioned experimets, low vs. high phosphate medium, cultured for 1 and 4 days
Project description:sequential changes in gene expression profiles in the gastric adenoma-carcinoma sequence by analyzing eight patient-matched gastric normal mucosa, adenomas and carcinomas.
Project description:Myoepithelioma, mixed tumor and parachordoma are rare soft tissue tumors thought to represent different morphologic variants of the same family of tumors, hereafter referred to as MMP tumors. The genetic basis of these neoplasms is poorly investigated. However, they morphologically resemble mixed tumor of the salivary glands (a.k.a. pleomorphic adenoma). This is the first study characterizing whole genome DNA copy number changes in MMP tumors and the genomic imbalances detected in four MMP tumors and one pleomorphic adenoma were diverse. The only recurrent aberration of known importance for tumor development was homo- and heterozygous deletions of the region in 9p21-22 which harbors the CDKN2A and CDKN2B genes. Defined by the deletion in case 3, the region 1.27-4.82 Mb on chromosome 19 was heterozygously lost in all cases, including the pleomorphic adenoma. A complex pattern of aberrations was seen in the primary tumor of case 2 with amplifications, interrupted by normal copy numbers and losses, of regions on chromosomes 6, 9, and 13. Keywords: comparative genomic hybridization, soft tissue myoepithelioma, mixed tumor, parachordoma, pleomorphic adenoma
Project description:Secondary hyperparathyroidism (SHP) is a common complication of chronic kidney disease (CKD) and correlates with morbidity and mortality. In this study we profiled microRNAs (miRNA) in parathyroids from different experimental SHP models and uremic patients and studied the function of specific miRNA using antagonizing oligonucleotides (anti-miRs). miRNA profiles established by small RNA deep sequencing showed that human, rat and mouse parathyroids share the same most abundant miRNAs. Principal component analyses clearly segregated parathyroids from SHP rats from normal rats, based on their miRNA expression profiles. Similar findings were observed in hyperplastic parathyroids from CKD patients compared to normal parathyroids from patients without kidney disease. We identifed specific parathyroid miRNAs that were dysregulated in all experimental SHP models studied. let-7i was decreased and miR-141 and miR-148a were increased in the parathyroids of rats with prolonged CKD induced by an 8 w adenine high phosphorus diet. Down-regulation of let-7 by anti-miRs increased PTH secretion in normal and in CKD rats, as well as in parathyroid organ cultures. Anti-miR-148 prevented the increase in serum PTH in CKD rats and decreased secreted PTH in parathyroid organ cultures. Our findings characterized parathyroid miRNA profiles and demonstrated conservation of the abundant miRNAs in different species. The evolutionary conservation of abundant miRNAs and their regulation in SHP suggest that miRNAs are important for parathyroid function and the development of SHP. Down-regulation of let-7 and miR-148 affects PTH secretion in vivo and in vitro, suggesting a role for these miRNAs in SHP. We propose that let-7 restrains while miR-148 promotes PTH secretion. In CKD, the decrease in parathyroid let-7 and the increase in miR-148 miRNAs may contribute to the development of SHP.
Project description:sequential changes in gene expression profiles in the gastric adenoma-carcinoma sequence by analyzing eight patient-matched gastric normal mucosa, adenomas and carcinomas. We examined gene expression changes during the gastric adenoma-carcinoma sequence in 26 snap-frozen samples (normal mucosa, adenoma, and carcinoma samples from eight patients and two additional carcinomas) by oligonucleotide microarray