Effects of dynamic pressure on the expression of PTHrP mRNA in metaphyseal cartilage stem cells of rats / 西安交通大学学报(医学版)

Objective To study the effect of dynamic pressure on the expression of parathyroid hormone-related protein (PTHrP)mRNA in metaphyseal cartilage stem cells of rats so as to further explore whether fiber actin (F-actin)is involved in the mechanical signal transduction process.Methods We isolated and cultured metaphyseal cartilage stem cells of rats by immunomagnetic beads.The third-generation rat metaphyseal cartilage stem cells were randomly divided into four groups:0%,3%,6%,and 12% deformed groups according to the size of dynamic pressure strength.We used a self-prepared dynamic tonic culture device to exert different intensity of pressure on each group of cells for 24 hours.Flow cytometry was used to detect the cell cycle distribution and apoptosis rate.The expression of PTHrP mRNA in each group was detected by Rea-l time quantitative PCR. Furthermore,the third-generation rat metaphyseal cartilage stem cells were randomly divided into four groups:control group,simple pressure group (6% deformation),pressure+cytoskeleton relaxin D group,and simple cytoskeleton relaxin D group according to whether or not to apply pressure and cytoskeleton relaxin D.F-actin fibers in each group of cells were stained with phalloidin and placed under a laser scanning confocal microscope.The expression of PTHrP mRNA in each group was detected by Real-time quantitative PCR.Results The results of flow cytometry showed no significant difference in G0/G1,G2/M and S phases between 0%,3%,6% and 12% deformed groups (P＞0.05).There was no significant difference in the apoptosis rate between 3% and 6% deformed groups compared with 0% deformed group (P＞0.05).The apoptosis rate was significantly higher in 1 2 % deformed group than in control group (P＜0.05).The results of laser confocal microscopy showed that the arrangement of F-actin fibers in the pressure group was neat and parallel compared with that in the control group, which was consistent with the direction of force.The intracellular F-actin fiber structure in pressure+cytoskeleton relaxin D group and simple cytoskeleton relaxin D group was destroyed and aggregated into clusters.Real-time quantitative PCR results showed that PTHrP mRNA expression did not significantly differ between 3% and 0% deformed groups (P＞0.05).The expression of PTHrP mRNA in 6% and 12% deformed groups was significantly higher than that in 0% group (P＜0.05).The expression of PTHrP mRNA in the cells of simple pressure group was significantly higher than that in the control group (P＜0.05).There was no significant difference in the expression of PTHrP mRNA between simple cytoskeleton relaxin D group and control group (P＞0.05).The mRNA expression of PTHrP was higher in pressure+cytoskeleton relaxin D group than that in control group,but lower than in simple pressure group (P＜0.05).Conclusion The dynamic pressure of proper intensity can increase the mRNA expression of PTHrP in chondrocytes of metaphyseal hypertrophy in rats,and F-actin is involved in the mechanical signal transduction process.

Progress of research on parathyroid hormone-related protein and bone metabolism / 基础医学与临床

PTH-related protein (PTHrP) is an abundant factor in bone which shows paracrine,endocrine,autocrine functions combined with PTHrP receptor and plays an important role in bone metabolism.Rencent years have witnessed that PTHrP plays a significant therapeutic effect on osteoporosis and exhibits some new functions.

Bone and mineral metabolism in primiparous women and its relationship with breastfeeding: a longitudinal study / Metabolismo óseo y mineral en mujeres primíparas y su relación con la lactancia: un estudio longitudinal

The aim of this study was to evaluate the changes in bone metabolism in breastfeeding women (BF). We selected 30 primiparous women and compared them to 31 nulliparous women. We assessed bone mineral density (BMD) in the lumbar spine (LS), femoral neck (FN) and trochanter (TROC), biochemical parameters of bone turnover and hormone and cytokine levels at the puerperium, 6 months and 12 months after delivery. A trend to lower BMD of LS was seen at initial evaluation in BF. BMD in LS, FN, and TROC were increased 12 months after delivery. Baseline body mass index was higher in puerperal women (p = 0.02) and correlated with an increased FN and TROC BMD one year post delivery (p = 0.001 and p = 0.003). An increase in bone remodeling markers, and lower urinary calcium was observed; after 12 months these values normalized. Prolactin, parathormone related peptide (PTHrP) and IL-6 were enhanced during the first six months of breastfeeding. We conclude that calcium for breastfeeding was obtained by transient mobilization of calcium deposits from the trabecular bone, and urinary calcium sparing induced by calciotrophic hormones and cytokines. Body weigth is an important factor in proximal femur BMD.

El objetivo de este estudio fue evaluar los cambios que suceden en el metabolismo óseo de mujeres que amamantan. Se seleccionaron 30 mujeres primíparas y se compararon con 30 mujeres nulíparas como grupo control. Se evaluó la densidad mineral ósea (DMO) del raquis lumbar (RL), cuello femoral (CF) y trocánter (TROC), parámetros del remodelado óseo, hormonas y citoquinas. Estos parámetros se midieron en el puerperio inmediato, y a los 6 y 12 meses post-parto. La DMO del RL de la mujeres primíparas evidenciaron una tendencia a menores valores al comienzo de la lactancia comparadas con las mujeres controles, y se observó un incremento significativo de la DMO a los 12 meses, alcanzando valores similares al grupo control. La DMO en CF y del TROC aumentó significativamente a los 12 meses post parto. El índice de masa corporal basal fue mayor en el grupo de primíparas en el puerperio inmediato (p = 0.02) y correlacionó con el incremento observado en la DMO CF y del TROC al año del post-parto (p = 0.001 y p = 0.003, respectivamente). Un alto remodelado óseo y descenso en el calcio urinario se observaron en el puerperio inmediato, y tanto los marcadores óseos como la calciuria se normalizaron a los 12 meses post-parto. Prolactina, interleuquina-6 y el PTHrP aumentaron significativamente en los primeros 6 meses. Concluimos que el calcio de la leche materna proviene de la movilización de los depósitos cálcicos del hueso trabecular y del ahorro de la pérdida renal inducido por las hormonas calcitrópicas y las citoquinas involucradas en el metabolismo óseo. El peso corporal es un factor de importancia en el incremento de DMO del fémur proximal.

Effect of losartan on expression of PTHrP and PTH1R induced by high glucose in NRK-52E cells / 中华内分泌代谢杂志

To study the effect of losartan on high glucose up-regulated expression of parathyroid hormone-related peptide (PTHrP) and its type 1 receptor (PTH1R) in NRK-52E cells. The expression of PTHrP and PTH1R were detected by RT-PCR and Western blot in control group (0 mmol/L glucose) ,normal glucose group (5 mmol/ L glucose) ,moderately high glucose group (16.7 mmol/L glucose) ,high glucose group (25 mmol/L glucose) ,and after intervention by 10 μmol/L losartan for 72 h (only Western blot). The expression of PTHrP and PTH1R were up-regulated by high glucose (PTHrP mRNA : 0. 66 ± 0.08, 0. 84 ± 0. 13,1.57 ± 0. 15, and 1.73 ± 0.21 ; PTHrP protein :0.63±0.12,0.68±0.06,1.02±0. 11, and 1.04±0.08 ; PTH1R mRNA :0.26±0. 08,0.28±0.07,2.35± 0. 10,and 2.47±0. 05 ; PTH1R protein:0. 88±0. 05,0. 87±0. 10, 1.05±0. 11, and 1.12±0. 09) ,and losartan inhibited the effects of high glucose (PTHrP 0.74±0. 15, PTH1R 0.98±0.06, both P<0.01). The results suggest that losartan could inhibit the expression of FTHrP and PTH1R induced by high glucose in NRK-52E.

Association between calcium intake, parathormone levels and blood pressure during pregnancy / Asociación entre consumo de calcio, niveles de parathormona y presión arterial en el embarazo

Purpose: To evaluate the association between calcium intake from diet, calciotropic hormones (PTH, PTH-rp), vasoactive regulators (endothelin, nitric oxide) and blood pressure levels during pregnancy, birth and puerperium. Method: In a prospective study 149 healthy normotensive primigravidas were followed-up from 15 weeks of gestation to puerperium. Daily calcium intake, calciuria, PTH, PTH-rp, endothelin, nitrite-nitrate, and Holter Test were assessed. Linear regression models were performed to evaluate the association between calcium intake, blood pressure levels and the laboratory tests. Multivariate regression models were performed to control potential confounders. Results: A significant increase of calcium intake during pregnancy was observed (931±301 mg/day to 1,195±467 mg/day, p<0.001). Plasma PTH-rp, endothelin, and nitrite-nitrate levels did not change during pregnancy. Among the women 38 (25.4%) had low calcium intake (<800 mg/day) with a larger increase of systolic and diastolic blood pressure during pregnancy (p=0.04) birth (p=0.006) and puerperium (p=0.01). After adjusting for other factors the multivariate analyses showed statistical association between low calcium intake, high parathormone levels and high systolic blood pressure levels during pregnancy (p=0.002). Conclusion: Low calcium intake during pregnancy is associated with a larger increase of systolic blood pressure and high parathormone levels.

Objetivo: Evaluar la asociación entre la ingesta de calcio en el embarazo, los niveles de presión arterial, las hormonas calciotrópicas (PTH, PTH-rp) y sustancias vasorreguladoras (endotelina, óxido nítrico). Métodos: Se realizó un estudio prospectivo con 149 primigrávidas normotensas que fueron incluidas en la semana 15 de gestación con seguimiento y evaluación hasta el puerperio. Se evaluó la ingesta diaria de calcio, la monitoría Holter de 24 horas, la calciuria, PTH, PTH-rp, la endotelina, nitritos y nitratos. Se siguieron modelos de regresión lineal para evaluar la asociación entre la ingesta de calcio, la presión arterial, las hormonas calciotrópicas y los vasorreguladores. Para controlar las variables de confusión se hicieron modelos de regresión múltiple. Resultados: Durante el embarazo la ingesta de calcio aumentó significativamente (931±301 mg/día a 1,195±467 mg/día, p<0.001). Entre las embarazadas 38 (25.4%) tuvieron una baja ingesta de calcio (<800 mg/día) asociada con mayores niveles de presión arterial sistólica y diastólica durante el embarazo (p=0.04), en el parto (p=0.006) y en el puerperio (p=0.01). Los mayores niveles de presión arterial sistólica durante el embarazo se asociaron con mayores niveles de paratormona y con menores niveles de ingesta de calcio (p=0.002). Los niveles plasmáticos de PTH-rp, endotelina, nitritos y nitratos no mostraron cambios durante el embarazo. Conclusión: La baja ingesta de calcio en el embarazo se asoció con mayores niveles de paratormona y de presión arterial sistólica durante el embarazo.

Epitheliotropic cutaneous lymphoma (mycosis fungoides) in a dog

A seven-year-old castrated male Yorkshire terrier dog was presented for a recurrent skin disease. Erythematous skin during the first visit progressed from multiple plaques to patch lesions and exudative erosion in the oral mucosa membrane. Biopsy samples were taken from erythematous skin and were diagnosed with epitheliotropic T cell cutaneous lymphoma by histopathology and immunochemical stain. In serum chemistry, the dog had a hypercalcemia (15.7 mg/dl) and mild increased alkaline phosphatase (417 U/l). Immunohistochemistry was performed to detect parathyroid hormone-related peptide (PTH-rP) in epitheliotropic cutaneous lymphoma tissues but the neoplastic cells were not labeled with anti-PTH-rP antibodies. The patient was treated with prednisolone and isotretinoin. However, the dog died unexpectedly.

Effect of simvastatin on the resorption of calvaria bone induced by parathyroid hormone-related peptide in mice / 中国矫形外科杂志

[Objective]To investigate the effect of simvastatin on the osteoclast and the focal resorptin of calvaria bone.[Method]Animal model of calvaria bone resorption was induced by parathyroid hormone-related peptide in mice.[Result]Simvastatin on the dose of 10,20 mg/kg/d could inhibit the resorption of calvaria bone and the formation of osteoclast,while,no significant inhibition was observed on the low dose(0,5 mg/kd/d).[Conclusion]Simvastation can effectively inhibit the resorption of focal bone in mice.It may provide an important strategy in treatment of diseases involved focal bone resorption.

Effect of simvastatin on the osteoclastic resorption stimulated by PTHrP and anabolism with murine calvarial organ culture in vitro / 中国矫形外科杂志

[Objective]To study the effect of simvastatin in the osteoclastic resorption stimulated by PTHrP and murine bone anabolism in vitro.[Method]The bone resorption activities of the osteoclast stimulated by PTHrP were evaluated after treatment with simvastatin for 8 days in vitro;the concentration of Ca~(2+) in the supernatant was also detected by atomic absorption spectrometer.The concentration of ALP and Ca~(2+) of the supematant in murine calvarial organ culture were detected.The histology of calvaria was observed.[Result]Simvastatin greatly inhibited the osteoclastic bone resorption stimulated by PTHrP in vitro and reduced the release of Ca~(2+).Simvastatin increased the ALP activities and bone mineralization of murines calvarial organ culture in vitro.[Conclusion]Simvastatin may inhibit the osteoclasric resorption stimulated by PTHrP and promote osteoblast differentiation and bone mineralization in vitro,thus play an important role in the prevention and treatment of osteoporosis.

A case of postpregnancy spinal osteoporosis / 대한내과학회지

Osteoporosis associated with pregnancy is rare, but it is accompanied by a substantial bone loss, resulting in fracture by minimal trauma. Nevertheless, this clinical significance is often ignored because the pain in various parts of the body is taken as an integral part of the pregnancy and it is possible that milder forms of this condition go unnoticed. Also, this disease is often confused with a variety of other condition associated with pregnancy and misdiagnosed. Although its etiology is still unknown, but variant theory is speculated. Pregnancy and lactation increase the demand on the maternal skeletal calcium restores and underlying genetic susceptibility may cause it. Recently it has been proposed that PTH-related protein may be an important causative factor. There are three types of the pregnancy associated osteoporosis, a transient osteoporosis of the hip in pregnancy, a postpregnancy spinal osteoporosis and a lactation-associated osteoporosis. We present a case of 24-years old women with postpregnancy spinal osteoporosis that showed multiple lumbar compression fracture and biochemical evidence of increased bone resorption.

A Case of Postpregnancy Spinal Osteoporosis / 대한내분비학회지

Osteoporosis is a common disease of the elderly and occurs especially in the postmenopausal women. Rarely, it occurs during a pregnancy or shortly thereafter and is accompanied by a substantial bone loss, resulting in fractures. The clinical significance of pregnancy-associated osteoporosis has been noted since the 1950s. Although its etiology is still unknown, it has recently been proposed that PTHrP may be an important causative factor in pregnancy-associated osteoporosis. There are three types of the pregnancy-associated osteoporosis, (1) a transient osteoporosis of the hip pregnancy, (2) a postpregnancy spinal osteoporosis and (3) a lactation-associated osteoporosis. Postpregnancy spinal osteoporosis typically occurs within three months after a first delivery and usually involving the axial skeleton accompanied by back pain, bone loss and a fracture. We present a case of postpregnancy spinal osteoporosis that developed three months after a first delivery. Our patient also showed multiple compression fractures in her lumbar spine and biochemical evidence of increased bone resorption.

OPG/RANKL gene expression of bone marrow stromal cell under stimulation of PTHrP / 中华风湿病学杂志

Objective To study the OPG/RANKL gene expression of bone marrow stromal cell under stimulation of PTHrP.Method Primary bone marrow cells were cultured under the stimulation of 45 ng/ml PTHrP. Number of osteoclasts was counted after 6-day's culture.90 ng/ml PTHrP was used to stimulate adherent bone marrow stromal cells for 3 or 6 days.OPG and RANKL gene expression level were determined by real-time PCR. Result Large number of osteoclasts were formed in primary bone marrow cell culture after 6-day stimulation of PTHrP.RANKL gene expression level was up-regulated by PTHrP,while OPG gene expression level were down-regulated.Conclusion PTHrP stimulates osteoclast formation via up-regulating RANKL level and down-regulating OPG level.

Circannual rhythms of parathyroid hormone-related protein in growing rats after functional mandibular protrusion / 实用口腔医学杂志

Objective:To investigate the levels of parathyroid hormo ne -related protein(PTHrP) in mandibular condylar cartilage during mandible forwar d positioning in different seasons. Methods:64 SD rats were rand omly divided into four groups according to seasons. Orthodontic appliance was us ed in 32 rats for 12 hours each day in daytime for mandibular protrusion. 8 rats were sacrificed at each season time point.Condyle samples were processed for PT HrP detection by a two-site immunoradiometric assay (IRMA) method.Another 32 ra ts without treatment were used as the controls.Macroscopic and microscopic appro ach were applied to analyze the results. Results:The level of P THrP in mandibular condylar cartilage(MCC) in the group of orthodontic treatmen t was higher than that in the control group(P

A Case of Humoral Hypercalcemia of Malignancy Associated with Hepatoma: A Case in which both PTHrP and 1,25 (OH) 2D were elevated / 대한내분비학회지

Hypercalcemia is one of the most common paraneoplastic syndromes and believed to occur through two general mechanisms, one humoral and the other local. The former mechanism has been termed humoral hypercalcemia of malignancy (HHM) and has been associated with the secretion of various cytokines, including parathyroid hormone-related protein (PTHrP). PTHrP beats sttuctural and functional similarities to PTH and seems to play a key role in the pathogenesis of HHM. We experienced the case of HHM associated with hepatoma, a rare cause of HHM, in 48 year-old male. We found no evidence of bone metastasis. In this case, contrary to our general acknowledgment, serum 1,25 (OH)D concentration was elevated. We report this case with a brief review of related literatures.

Simultaneous elevation of serum parathyroid hormone(PTH) and parathyroid hormone-related protein(PTHrP) in a case of lung cancer with hypercalcemia / 결핵

The parathyroid hormone related protein(PTHrP) is the most common causative peptide of humoral hypercalcemia of malignancy. In contrast, the serum level of parathyroid hormone(PTH) is low to undetectable in the majority of patients with malignancy associated hypercalcemia. Few cases exist in which the production and secretion of PTH by malignant nonparathyroid tumors have been authenticated. To our knowledge, there is very rare case in which a nonparathyroid tumor expressed simultaneously both the PTH and PTHrP. We report a case of squamous cell carcinoma of the lung with hypercalcemia which presented with simultaneous elevation of serum PTH and PTHrP. Severe hypercalcemia (serum calcium, 7.5mEq/L) was found in a 65-year-old man who had a squamous cell carcinoma of the lung without any body metastasis and detectable parathyroid abnormalities on isotope scintigraphy. The serum level of intact parathyroid hormone (PTH) concentration was markedly elevated as measured in two site radioimmunoreactive PTH assays (intact PTH 150pg/mL ; normal 9~55). The serum level of a PTHrP was also increased as measured in C-terminal region specific radioimmunoassay (PTHrP 99.1 pmol/L ; normal 13.8~55.3). There are no evidences of coincidental primary hyperparathyroidism in parathyroid MIBI scan and other imaging studies including neck ultrasonography and computed tomography. These results suggest that simultaneous elevation of serum PTH and PTHrP in this patient can be caused by production of both PTHrP and PTH in other nonparathyroid lesions such as squamous cell carcinoma.

Expression of PTH/PTHrP receptor mRNA on osteoblast in hemodialysis patients / 中华肾脏病杂志

Objective To investigate the expression of parathyroid hormone/parathyroid hormone relative protein (PTH/PTHrP) receptor of osteoblast in hemodialysis patients and the effects of calcium channel blocker(CCB) and calcitriol on it. Methods Twenty-one patients on HD were randomly divided into three groups. Six patients were treated with CCB for 8 weeks. Seven patients were given calcitriol for 8 weeks. The rest 8 cases did not take either CCB or calcitriol. Five healthy people were selected as control group. The serum levels of iPTH, BUN, Scr, calcium and phosphorus were measured. The osteoblast was prepared from cultured bone marrow. PTH receptor mRNA expression was detected by semi-quantitive RT-PCR. Results The level of PTH/PTHrP receptor mRNA decreased significantly in patients on HD as compared with control group, and increased in patients with CCB. In calcitriol treated group, and PTH/PTHrP receptor was obviously down-regulated with larger dose of calcitriol(0. 75?g/d), and up-regulated with low dose(0. 25?g/d) . Conclusion Expression of PTH/PTHrP receptor down-regulates in osteoblast of HD patients. CCB can up-regulate the expression of PTH/PTHrP receptor. A large dose of calcitriol may decrease iPTH level and down-regulate PTH/PTHrP receptor expression.