BACKGROUND: Although osteopontin (OPN) is expressed in the liver and pigment gallstones of patients with hepatolithiasis, its role in pigment gallstone formation remains unclear. This study aimed to explore the function of OPN in pigment gallstone formation. METHODS: Rats were fed a chow diet (CD) or lithogenic diet (LD) for 10 consecutive weeks; blocking tests were then performed using an OPN antibody (OPN-Ab). Incidence of gallstones and levels of several bile components, OPN, tumor necrosis factor alpha (TNF-α), and cholesterol 7 alpha-hydroxylase (CYP7A1) were analyzed. To determine TNF-α expression in hepatic macrophages and both CYP7A1 and bile acid (BA) expression in liver cells, recombinant rat OPN and recombinant rat TNF-α were used to treat rat hepatic macrophages and rat liver cells, respectively. Chi-square or Fisher exact tests were used to analyze qualitative data, Student t-test or one-way analysis of variance were used to analyze qualitative data. RESULTS: Incidence of gallstones was higher in LD-fed rats than in CD-fed rats (80% vs. 10%, P < 0.05). BA content significantly decreased in bile (t = -36.08, P < 0.01) and liver tissue (t = -16.16, P < 0.01) of LD-fed rats. Both hepatic OPN protein expression (t = 9.78, P < 0.01) and TNF-α level (t = 8.83, P < 0.01) distinctly increased in the LD group; what's more, CYP7A1 mRNA and protein levels (t = -12.35, P < 0.01) were markedly down-regulated in the LD group. Following OPN-Ab pretreatment, gallstone formation decreased (85% vs. 25%, χ2 = 14.55, P < 0.01), liver TNF-α expression (F = 20.36, P < 0.01) was down-regulated in the LD group, and CYP7A1 expression (F = 17.51, P < 0.01) was up-regulated. Through CD44 and integrin receptors, OPN promoted TNF-α production in macrophage (F = 1041, P < 0.01), which suppressed CYP7A1 expression (F = 48.08, P < 0.01) and reduced liver BA synthesis (F = 119.4, P < 0.01). CONCLUSIONS We provide novel evidence of OPN involvement in pigmented gallstone pathogenesis in rats.
Animals ; Diet/adverse effects* ; Gallstones/etiology* ; Lithiasis ; Liver ; Liver Diseases ; Osteopontin/genetics* ; Rats

Carcinoma, Hepatocellular ; metabolism ; Glycoproteins ; biosynthesis ; genetics ; Humans ; Hyaluronan Receptors ; biosynthesis ; genetics ; Liver ; metabolism ; Liver Neoplasms ; metabolism ; Osteopontin ; biosynthesis ; genetics

BACKGROUNDThe precise mechanisms responsible for the development and growth of intracranial arteriovenous malformations (AVMs) remain unclear. Osteopontin (OPN) is a phosphorylated glycoprotein with diverse functions. This study aimed to analyze the expression of OPN in human brain AVMs.

METHODSThe AVM nidus was surgically obtained from patients with AVM, whereas control brain artery specimens were surgically obtained from patients with epilepsy. Reverse transcription-polymerase chain reaction (RT-PCR) was used to examine the expression of OPN mRNA in biopsy specimens. OPN protein expression was localized by immunohistochemistry. The statistical differences between different groups were assessed by two-way analysis of variance (ANOVA).

RESULTSWe analyzed 36 brain AVM specimens and 8 control brain artery specimens. Eleven patients with brain AVM received embolization treatment, and five underwent gamma knife radiotherapy before resection. Nineteen patients with brain AVM had a history of hemorrhage from AVMs. The expression of OPN mRNA was significantly higher in AVMs than that in the control specimens (25.76 ± 2.71 vs. 21.46 ± 2.01, P < 0.01). There was no statistically significant difference in the extent of OPN mRNA expression between the AVM group with and that without history of hemorrhage (26.13 ± 2.45 vs. 25.34 ± 2.99) or gamma knife radiotherapy (24.39 ± 2.10 vs. 24.53 ± 1.85). However, the difference between the AVM group with and that without embolization treatment history was statistically significant (24.39 ± 2.10 vs. 28.80 ± 1.13, P < 0.01). In the group with gamma knife radiotherapy history, OPN expression was found in arteries with early-stage radio-effect.

CONCLUSIONSOPN may contribute to the vascular instability of brain AVMs. It may play an important role in the pathophysiological process related to embolization treatment.

Analysis of Variance ; Brain ; metabolism ; pathology ; Immunohistochemistry ; Intracranial Arteriovenous Malformations ; genetics ; metabolism ; pathology ; Osteopontin ; genetics ; metabolism ; Reverse Transcriptase Polymerase Chain Reaction

OBJECTIVETo investigate the regulation effects of upstream stimulatory factor 1 (USF1) on osteopontin expression in odontoblasts.

METHODSOdontoblast MDPC-23 was cultured and stably transfected with PCMV-USF1 or A-USF plasmids. Total RNA was extracted and osteopontin expression examined by semi-quantitative RT-PCR. Gray value of osteopontin was measured and statistic analysis performed.

RESULTSClones of stable PCMV-USF1 and A-USF plasmids transfection were obtained. Compared with the control, osteopontin was upregulated in PCMV-USF1 transfection group, and downregulated in A-USF transfection group.

CONCLUSIONSUpstream stimulatory factor 1 could regulate the osteopontin expression in odontoblasts, which could be blocked partly by A-USF.

Cell Line, Tumor ; Humans ; Odontoblasts ; metabolism ; Osteopontin ; genetics ; metabolism ; Plasmids ; genetics ; RNA, Messenger ; genetics ; Reverse Transcriptase Polymerase Chain Reaction ; Transfection ; Upstream Stimulatory Factors ; genetics

BACKGROUNDOsteopontin (OPN) is one kind of cytokine which can play a number of roles in promoting activation of T lymphocyte, regulating balance between Th1 and Th2, participating in cell-induced immunologic response and stimulating B lymphocyte to express multi-clone antibodies. Some researches have showed that OPN may be involved in the pathogenesis of systemic lupus erythematosus (SLE). The aim of this study was to investigate possible association of a single nucleotide polymorphism (SNP) at position 9250 in exon 7 of the OPN gene (OPN gene 9250) with SLE in Chinese patients.

METHODSTotally 158 patients (18 males and 140 females) fulfilled the revised criteria for SLE by the American College of Rheumatology in 1982 and 180 healthy volunteer controls (34 males and 146 females), all from the south of China, consented to participate in the study. OPN gene 9250 polymorphism was detected by polymerase chain reaction and restriction fragment length polymorphism (PCR-RFLP).

RESULTSThe frequency of TT genotype of the OPN gene 9250 was significantly lower (52.5% vs 70%, P < 0.05) and the frequency of TC genotype of the OPN gene 9250 was significantly higher (43.7% vs 29.4%, P < 0.05) in SLE patients than in controls. There were significant differences in OPN gene 9250 allele and phenotype frequencies between the SLE patients and controls (P < 0.05). When the SLE patients and controls were separated into men and women, significant differences of frequencies were noted in TT genotype, TC genotype and allele of the OPN gene 9250 in women (P < 0.05) but not in men (P > 0.05).

CONCLUSIONSOPN gene 9250 polymorphism appears to be associated with susceptibility to SLE in Chinese Han ethnic population.

Adolescent ; Adult ; Aged ; China ; ethnology ; Female ; Humans ; Lupus Erythematosus, Systemic ; genetics ; Lupus Nephritis ; genetics ; Male ; Middle Aged ; Osteopontin ; genetics ; Polymerase Chain Reaction ; Polymorphism, Genetic ; Polymorphism, Restriction Fragment Length

Cleft lip and/or palate (CL/P) is a common congenital malformation with a complex etiology which is not fully elucidated yet. Epidemiological studies point to different etiologies in the cleft lip and palate subgroups, isolated cleft lip (CL), isolated cleft palate (CP) and combined cleft lip and palate (CLP). In order to understand the biological basis in these cleft lip and palate subgroups better we studied the expression profiles in human tissue from patients with CL/P. In each of the CL/P subgroups, samples were obtained from three patients and gene expression analysis was performed. Moreover, selected differentially expressed genes were analyzed by quantitative RT-PCR, and by immunohistochemical staining of craniofacial tissue from human embryos. Osteopontin (SPP1) and other immune related genes were significantly higher expressed in palate tissue from patients with CLP compared to CP and immunostaining in palatal shelves against SPP1, chemokine receptor 4 (CXCR4) and serglycin (PRG1) in human embryonic craniofacial tissue were positive, supporting a role for these genes in palatal development. However, gene expression profiles are subject to variations during growth and therefore we recommend that future gene expression in CL/P studies should use tissue from the correct embryonic time and place if possible, to overcome the biases in the presented study.
Cleft Lip/*genetics/*immunology ; Cleft Palate/embryology/*genetics/*immunology ; Gene Expression Profiling ; Humans ; Immunohistochemistry ; Infant ; Oligonucleotide Array Sequence Analysis ; Osteopontin/*genetics/immunology ; Reverse Transcriptase Polymerase Chain Reaction

OBJECTIVETo determine the expression of osteopontin (OPN) and survivin in prostate cancer tissue, and study their correlation and roles in tumor invasion and metastasis.

METHODSThe expressions of OPN and survivin in prostate cancer tissue, prostate hyperplasia tissue and normal prostate tissue were determined by RT-PCR and immunohistochemistry.

RESULTSThe positive expression rates of OPN mRNA and protein in prostate cancer tissue [76.1% (35/46) and 69.6% (32/46)] were significantly correlated to survivin expression [67.4% (31/46) and 67.4% (31/46)] (P<0.05). The expressions of OPN and survivin were related to the tumor grade and clinical stages (P<0.05). OPN and survivin were not found in prostate hyperplasia and normal prostate tissues.

CONCLUSIONOPN and survivin may play important roles in the progression of prostate cancer and can be potential markers for invasion and metastasis of prostate cancer. OPN and survivin might play synergetic roles in prostate carcinogenesis.

Adult ; Aged ; Humans ; Inhibitor of Apoptosis Proteins ; genetics ; metabolism ; Male ; Middle Aged ; Neoplasm Invasiveness ; Neoplasm Metastasis ; Osteopontin ; biosynthesis ; genetics ; Prostatic Neoplasms ; metabolism ; pathology ; RNA, Messenger ; genetics ; metabolism

BACKGROUNDExposure of adult mice to more than 95% O2 produces a lethal injury by 72 hours. Nuclear factor kappa B (NF-κB) is a transcriptional factor that plays a key role in the modulation of cytokine networks during hyperoxia-induced acute lung injury (ALI). Osteopontin (OPN) is a phosphorylated glycoprotein produced principally by macrophages. Studies have reported that exogenous OPN can maintain the integrity of the cerebral microvascular basement membrane and reduce brain damage through inhibiting NF-κB activities in the brain after subarachnoid hemorrhage. However, it is not clear whether OPN can reduce lung injury during ALI by inhibiting transcriptional signal pathways of NF-κB and consequent inhibition of inflammatory cytokines. Thus we examined the effects and mechanisms of recombinant OPN (r-OPN) on ALI.

METHODSNinety-six mice were randomly divided into phosphate buffered saline (PBS) and r-OPN groups. Mice were put in an oxygen chamber (>95% O2) and assessed for lung injury at 24, 48, and 72 hours. Expressions of NF-κB, matrix metalloproteinases 2 and 9 (MMP-2 and MMP-9), and tissue inhibitors of MMP-2 and MMP-9 (TIMP-1, TIMP-2) mRNA in lungs were examined with RT-PCR. Expression and distribution of NF-κB protein in lungs were measured with immunohistochemistry.

RESULTSExposure to hyperoxia for 72 hours induced more severe lung injury in the PBS group compared with the r-OPN group. Expression of NF-κB mRNA in the PBS group exposed to hyperoxia for 48 and 72 hours was significantly higher than the r-OPN group (P < 0.05). With 72-hour exposure, expression of TIMP-1 mRNA in the r-OPN group was significantly higher than that of the PBS group (P < 0.05). Expression of TIMP-2 mRNA in the r-OPN group at 48 and 72 hours was significantly higher than those in the PBS group (P < 0.05). After 72-hour exposure, expression of NF-κB protein in airway epithelium in the PBS group was significantly higher than that in the r-OPN group (P < 0.05).

CONCLUSIONr-OPN can inhibit the release and activation of MMPs through inhibition of the expression of NF-κB and promotion of the expression of TIMPs, and alleviate hyperoxia-induced ALI.

Acute Lung Injury ; genetics ; metabolism ; Animals ; Hyperoxia ; metabolism ; physiopathology ; Matrix Metalloproteinase 2 ; genetics ; metabolism ; Matrix Metalloproteinase 9 ; genetics ; metabolism ; Mice ; NF-kappa B ; genetics ; metabolism ; Osteopontin ; genetics ; metabolism ; Tissue Inhibitor of Metalloproteinase-1 ; genetics ; metabolism ; Tissue Inhibitor of Metalloproteinase-2 ; genetics ; metabolism

OBJECTIVETo investigate ORMDL3 polymorphisms in children with asthma in Hunan, China, and to determine the relationship between ORMDL3 polymorphisms and serum osteopontin (OPN) and transforming growth factor-β1 (TGF-β1) levels.

METHODSPeripheral blood samples were collected in children with asthma (n=98; astma group) or without asthma (n=30; control group) from Hunan, China. The asthma group was subdivided into atopic (n=62) and non-atopic (n=36) subgroups. Single nucleotide polymorphism (SNP) analysis was performed, and serum OPN and TGF-β1 levels were measured.

RESULTSThere were no significant differences in genotype and allele frequencies of rs7216389 of the ORMDL3 gene between the asthma and control groups. The serum level of OPN in the asthma group was significantly higher than in the control group (P<0.05). Both the atopic and non-atopic subgroups showed increased serum levels of OPN compared with the control group (P<0.05). The serum level of TGF-β1 in the atopic subgroup was significantly higher than in the control group (P<0.05). The serum levels of OPN and TGF-β1 showed no significant differences in asthmatic children with different genotypes. The serum levels of OPN and TGF-β1 were in a positive linear correlation in the asthma group (r=0.620; P<0.01) and its two subgroups (r=0.734, 0.649 respectively; P<0.01).

CONCLUSIONSIn children from Hunan, China, the SNP (rs7216389) of ORMDL3 is not related to asthma susceptibility. OPN and TGF-β1 may be involved in the development of asthma, and they are in a positive linear correlation. The SNP (rs7216389) of ORMDL3 does not influence the expression of OPN and TGF-β1, suggesting that it may not be associated with airway remodeling.

Airway Remodeling ; Asthma ; blood ; genetics ; Child, Preschool ; Female ; Humans ; Infant ; Infant, Newborn ; Male ; Membrane Proteins ; genetics ; Osteopontin ; blood ; Polymorphism, Single Nucleotide ; Transforming Growth Factor beta1 ; blood

BACKGROUNDExposure of adult mice to more than 95% O(2) produces a lethal injury by 72 hours. Nitric oxide synthase (NOS) is thought to contribute to the pathophysiology of murine hyperoxia-induced acute lung injury (ALI). Osteopontin (OPN) is a phosphorylated glycoprotein produced principally by macrophages. OPN inhibits inducible nitric oxide synthase (iNOS), which generates large amounts of nitric oxide production. However, the relationship between nitric oxide and endogenous OPN in lung tissue during hyperoxia-induced ALI has not yet been elucidated, thus we examined the role that OPN plays in the hyperoxia-induced lung injury and its relationships with NOS.

METHODSOne hundred and forty-four osteopontin knock-out (KO) mice and their matched wild type background control (WT) were exposed in sealed cages > 95% oxygen or room air for 24- 72 hours, and the severity of lung injury was assessed; expression of OPN, endothelial nitric oxide synthase (eNOS) and iNOS mRNA in lung tissues at 24, 48 and 72 hours of hyperoxia were studied by reverse transcription-polymerase chain reaction (RT-PCR); immunohistochemistry (IHC) was performed for the detection of iNOS, eNOS, and OPN protein in lung tissues.

RESULTSOPN KO mice developed more severe acute lung injury at 72 hours of hyperoxia. The wet/dry weight ratio increased to 6.85 +/- 0.66 in the KO mice at 72 hours of hyperoxia as compared to 5.31 +/- 0.92 in the WT group (P < 0.05). iNOS mRNA (48 hours: 1.04 +/- 0.08 vs. 0.63 +/- 0.09, P < 0.01; 72 hours: 0.89 +/- 0.08 vs. 0.72 +/- 0.09, P < 0.05) and eNOS mRNA (48 hours: 0.62 +/- 0.08 vs. 0.43 +/- 0.09, P < 0.05; 72 hours: 0.67 +/- 0.08 vs. 0.45 +/- 0.09, P < 0.05) expression was more significantly increased in OPN KO mice than their matched WT mice when exposed to hyperoxia. IHC study showed higher expression of iNOS (20.54 +/- 3.18 vs. 12.52 +/- 2.46, P < 0.05) and eNOS (19.83 +/- 5.64 vs. 9.45 +/- 3.82, P < 0.05) in lung tissues of OPN KO mice at 72 hours of hyperoxia.

CONCLUSIONOPN can protect against hyperoxia-induced lung injury by inhibiting NOS.

Animals ; Hyperoxia ; genetics ; physiopathology ; Immunohistochemistry ; Lung ; metabolism ; Lung Injury ; etiology ; genetics ; metabolism ; Mice ; Mice, Knockout ; Nitric Oxide Synthase ; genetics ; metabolism ; Nitric Oxide Synthase Type II ; genetics ; Nitric Oxide Synthase Type III ; genetics ; Osteopontin ; genetics ; physiology ; Reverse Transcriptase Polymerase Chain Reaction