Search results for "thyroid hormone"
showing 10 items of 166 documents
Current perspectives on parathyroid hormone (PTH) and PTH-related protein (PTHrP) as bone anabolic therapies.
2013
Osteoporosis is characterized by low bone mineral density and/or poor bone microarchitecture leading to an increased risk of fractures. The skeletal alterations in osteoporosis are a consequence of a relative deficit of bone formation compared to bone resorption. Osteoporosis therapies have mostly relied on antiresorptive drugs. An alternative therapeutic approach for osteoporosis is currently available, based on the intermittent administration of parathyroid hormone (PTH). Bone anabolism caused by PTH therapy is mainly accounted for by the ability of PTH to increase osteoblastogenesis and osteoblast survival. PTH and PTH-related protein (PTHrP)-an abundant local factor in bone- interact wi…
The new frontier of bone formation: a breakthrough in postmenopausal osteoporosis?
2009
Osteoporosis is a chronic disease that accelerates after menopause in many women. Most of the pharmacologic attempts to control the disease, such as hormone therapy, have emphasized the constraint of bone resorption. Since recent years have witnessed important advances in the field of bone formation, this review aims to update the present knowledge on the mechanisms affecting osteoblastogenesis and on the therapeutic results achieved by recently approved drugs.We sought peer-reviewed, full-length basic and clinical articles published between 1995 and May 2008 using a PubMed search strategy, with the terms osteoporosis and osteoblast, osteoporosis and strontium ranelate, and osteoporosis and…
Response of Bone Metabolism Markers to Ice Swimming in Regular Practitioners
2021
Objective: Both exercise and cold exposure cause physiological stress and they often occur in combination. However, the effects of exercise during severe cold on variation in bone metabolism in humans have remained elusive. The aim of this study was to investigate the variations in circulating bone metabolism markers after ice swimming (IS).Methods: Eighty-seven women and men aged 42–84 years old were recruited to perform regular IS activities. Serum parathyroid hormone (PTH), total calcium (Ca2+), total phosphorus (Pi), total magnesium (Mg2+), N-terminal osteocalcin (N-MID), total propeptide of procollagen 1 (TPINP), and C-terminal telopeptide of type 1 collagen (β-CTX) were measured 30 mi…
Midregion parathyroid hormone-related protein inhibits growth and invasion in vitro and tumorigenesis in vivo of human breast cancer cells.
2001
Parathyroid hormone-related protein (PTHrP) is critical for normal mammary development and is overexpressed by breast cancers. PTHrP is a peptide hormone that undergoes extensive post-translational processing, and PTHrP(38–94)-amide is one of the mature secretory forms of the peptide. In this study, we explored the effect of PTHrP(38–94)-amide in a panel of six breast cancer cell lines “in vitro” and in MDA-MB231 cells “in vivo” specifically examining cell viability, proliferation, invasiveness, and growth in nude mice. PTHrP(38–94)-amide markedly inhibited proliferation and also caused striking toxicity and accelerated cell death in breast cancer cells. In addition, direct injection of PTH…
Thyroid hormones induce sumoylation of the cold shock domain-containing protein PIPPin in developing rat brain and in cultured neurons.
2006
We previously identified a cold shock domain (CSD)-containing protein (PIPPin), expressed at high level in brain cells. PIPPin has the potential to undergo different post-translational modifications and might be a good candidate to regulate the synthesis of specific proteins in response to extracellular stimuli. Here we report the effects of thyroid hormone (T3) on PIPPin expression in developing rat brain. We found that a significant difference among euthyroid- and hypothyroid- newborn rats concerns sumoylation of nuclear PIPPin, that is abolished by hypothyroidism. Moreover, T3-dependence of PIPPin sumoylation has been confirmed in cortical neurons purified from brain cortices and culture…
Induction of the adrenoleukodystrophy-related gene (ABCD2) by thyromimetics.
2009
X-linked adrenoleukodystrophy (X-ALD) is a peroxisomal disorder caused by mutations in the ABCD1 (ALD) gene. The ABCD2 gene, its closest homolog, has been shown to compensate for ABCD1 deficiency when overexpressed. We previously demonstrated that the ABCD2 promoter contains a functional thyroid hormone response element. Thyroid hormone (T3) through its receptor TRbeta can induce hepatic Abcd2 expression in rodents and transiently normalize the VLCFA level in fibroblasts of Abcd1 null mice. In a therapeutic perspective, the use of selective agonists of TRbeta should present the advantage to be devoid of side effects, at least concerning the cardiotoxicity associated to TRalpha activation. I…
In vitro free radical scavenging capacity of thyroid hormones and structural analogues.
2001
It was reported that thyroid hormones decreased Cu(2+)-induced low-density lipoprotein (LDL) oxidation in vitro. Here, we investigated free radical scavenging capacities of thyroid hormones (3,5,3'-tri-iodo-L-thyronine (T(3)), thyroxine (T(4)) and 3,3',5'-tri-iodo-L-thyronine (rT(3))) and structural analogues (L-thyronine (T(0)), 3,5,3'tri-iodothyroacetic acid (TA(3)) and 3,5,3',5'-tetra-iodothyroacetic acid (TA(4))), using three different models of free radical generation. T(0), T(3) and TA(3) slowed down production of conjugated diene and thiobarbituric acid-reactive substances during LDL oxidation by 2,2'-azobis-[2-amidinopropane] (water-soluble), whereas rT(3), T(4) and TA(4) had practi…
Regulation of PTHrP and PTH/PTHrP receptor by extracellular Ca2+ concentration and hormones in the breast cancer cell line 8701-BC.
2000
AbstractIt was previously reported that 8701-BC breast tumour cells express the gene for parathyroid hormonerelated peptide (PTHrP) and PTH/PTHrP receptor (PTHrPR) and release immunoreactive PTHrP (iPTHrP) into the extracellular medium. Since the regulation of PTHrP and PTHrPR by breast cancer cells has been poorly investigated so far, we have chosen the 8701- BC cell line as a model system to investigate whether alterations in the extracellular Ca[2+] concentration ([Ca[2+]]) and treatment with some wellknown differentiation agents for breast cells, such as dimethyl sulfoxide, hydrocortisone, progesterone, prolactin, alltrans retinoic acid and transforming growth factorβ1 might (i) modulat…
Prospective evaluation of parathyroid graft function after total parathyroidectomy and heterotopic autotransplantation in renal hyperparathyroidism b…
1998
The value of gradients for intact parathyroid hormone (PTH) in the assessment of graft function after total parathyroidectomy/autotransplantation for renal hyperparathyroidism was evaluated in a prospective follow-up study. Altogether 99 patients who underwent operation from August 1, 1987 to December 31, 1996 were prospectively investigated and reexamined postoperatively, including analyses of serum calcium, alkaline phosphatase, and intact PTH in the antecubital venous blood of both arms. The postoperative course is known for all patients. Of the 99 patients included in the study, 95 underwent one to nine reexaminations (median three) over follow-up periods of 1 month to 5 years (median 2…
Modified cryopreservation and xenotransplantation of human parathyroid tissue.
1999
Introduction: A modified cryopreservation technique for human parathyroid tissue was compared with the standard method using a programmed freezer. Methods: Total parathyroidectomy was performed in three groups of 6-week-old Rowett nude rats. Group I (control) underwent no transplantation of parathyroid tissue (n=9). After 10 days, the rats of groups II (n=15) and III (n=15) underwent xenotransplantation of 20 mg cryopreserved human parathyroid tissue, which had been stored in liquid nitrogen at –196°C for 1–22 months prior to xenotransplantation. The parathyroid tissue was derived from 15 parathyroidectomized patients with renal hyperparathyroidism. Two tissue samples were obtained from eve…