Fast method for skeletal tissue gene expression analysis.

Several chronic diseases have been associated with bone alteration in the last few years. Despite the wealth of information provided by the analysis of the transcriptome in affected tissues, only a limited number of studies evaluated gene expression in bone tissue due to the difficulty to obtain high quality RNA. Therefore, skeletal pathologies have been often associated to a defective maturation process that occurs during recruitment of progenitor stem cells. In order to explore the possibility of analysing the gene expression during osteogenic differentiation in skeletal tissue, a single-step method to extract well-preserved RNA from bone specimens was performed. A comparison between this technique and a traditional method was made by analysing the quality and yield of RNA obtained. In addition, RNAs were assayed by reverse transcription-quantitative polymerase chain reaction to analyse the expression levels of the bone genes associated with the differentiation process in a mouse model. The present data showed that good quality RNA can be obtained from bone tissue by a simple single-step method allowing the expression analysis of the genes encoded by skeletal tissue. In conclusion, the present study allows the possibility to easily obtain good quality RNA from bone tissue that is suitable for gene expression studies of bone diseases.

Declining trends in the incidence of hip fractures in people aged 65years or over in years 2000-2011.

BACKGROUND: The aim of this study was to explore hip fracture (HFx) incidence in the Veneto Region of Italy, looking at potential differences with the national data. METHODS: We analyzed HFx incidence for people aged 65years or over, in years 2000-2011, using data from the Regional Hospitalization Database. Patients were stratified by sex, calendar year and 5-year age class. Data for the single provinces of the Region were also obtained. Absolute number of HFx, crude incidence for 10,000 inhabitants and age-standardized fracture rates were calculated. RESULTS: During the study period, there were 53,917 hospitalizations for HFx (77.7% in females). In the whole 11year period of observation, the absolute HFx number increased by 17.7% in males and 10.6% females, respectively. However, age-standardized incidence rates declined by 18% in the same period (IRR 0.82, 95% CI 0.78-0.87). This decreasing trend was almost identical through all the age-cohorts up to 84years. In the whole study period, HFx incidence was lower for Padova (IRR 0.63, 95% CI 0.60-0.66) and Verona (IRR 0.66, 95% CI 0.63-0.70) provinces as compared to the others. This regional profile was quite different with respect to the data published, for the same calendar years, for Italy as a whole, in spite of an almost identical demography of the population. CONCLUSIONS: HFx incidence is declining in the Veneto Region of Italy. Further studies, aimed to investigate factors involved in this figure are needed.

The relationship between the Spine Deformity Index, biochemical parameters of bone metabolism and vascular calcifications: results from the Epidemiological VERtebral FRACtures iTalian Study (EVERFRACT) in dialysis patients.

BACKGROUND: The Spine Deformity Index (SDI) is a measure of vertebral fractures (VFs), providing information on both their number and severity. METHODS: We evaluated the relationships between SDI and clinical, biochemical and arterial calcification parameters in 387 hemodialysis (HD) patients. VFs, assessed by quantitative vertebral morphometry, and vascular calcifications were identified in the same lateral spinal X-ray. To improve the detection of fracture severity, we created a corrected SDI (c-SDI), by dividing SDI for the number of VFs. We assessed routine biochemistry, bone-Gla-protein (BGP), undercaboxylated BGP (ucBGP), and matrix-Gla-protein (MGP). RESULTS: VFs prevalence was 55.3%. HD patients with a SDI >1 were more frequently males (p<0.05), and had lower BGP (p<0.01). Patients with a c-SDI >1 had higher LDL-cholesterol (p<0.05) and lower ucBGP (p<0.05) and MGP (p<0.05). Calcifications of the abdominal aorta (AAoC) were more frequent in patients with SDI >1 (p<0.05) and with c-SDI >1 (p<0.05). Multivariate logistic regression showed that male sex (OR 1.86, CI 1.20-2.91), age (OR 1.03, CI 1.01-1.05) and albumin ≥3.5 g/dL (OR 0.54, CI 0.31-0.93) were predictors of a SDI >1. Age (OR 1.05, CI 1.03-1.07), LDL-cholesterol (OR 1.74, CI 1.04-2.92) and ucBGP (OR 0.35, CI 0.18-0.70) were associated with c-SDI >1. CONCLUSIONS: We conclude that the severity of VFs was associated with age, atherogenic factors and bone metabolism markers.

Effects of time culture and prototypical cytochrome P450 3A (CYP3A) inducers on CYP2B22, CYP2C, CYP3A and nuclear receptor (NR) mRNAs in long-term cryopreserved pig hepatocytes (CPHs).

In the present study, transcriptional and post-translational effects of culturing time and prototypical cytochrome P450 3A (CYP3A) inducers on principal nuclear receptors (NRs), CYP2B22, 2C and 3A were investigated in long-term stored (~10 years) cryopreserved pig hepatocytes (CPHs). In the time-course study, a crush and rise effect was observed for pregnane X receptor (NR1I2) and constitutive androstane receptor (NR1I3) mRNAs, while a time-dependent increase of retinoid X receptor alpha (NR2B1) was noticed. Cytochrome P450 gene expression profiles were down-regulated as a function of time. In the induction study, an increase of NR1I2, NR1I3 and NR2B1 mRNAs was observed in dexamethasone-exposed CPHs. About CYPs, an overall up-regulation was seen in CPHs exposed to phenobarbital, while dexamethasone and rifampicin up-regulated only CYP3A. In both studies, transcriptional CYP results were confirmed at the post-translational level (immunoblotting and enzyme activities), except for CYP2B immunoblotting in the induction study. The present data demonstrate that long-term stored CPHs may be used to investigate mechanisms involved in CYPs regulation, expression and function; provide further info about NR regulation of CYPs, and confirm species-differences in these mechanisms of regulation; finally, they suggest the usefulness and relevance of gene expression profiling to early detect any modulation of CYP expression and bioactivity.

Densitometric threshold and vertebral fractures in heart transplant patients.

BACKGROUND: Bone disease is one of the major complications of solid organ transplantation, causes considerable morbidity, and most patients are treated with immunosuppressant drugs after graft. The majority of studies reported rapid bone loss and an increased incidence of fractures after transplantation. The aim of our study was to evaluate osteoporosis and fracture prevalence, bone metabolism, and the effect of immunosuppressant agents on bone after heart transplantation. METHODS: We planned a cross-sectional study in 180 heart transplant patients recruited from 3 different centers with a less than 10 years from graft. Each patient underwent a densitometric scan, and in 157 of them, an x-ray of the spine was performed to evaluate fractures. Biochemical assessment of bone metabolism was made at the time of the visit. Physical activity, diet, and calcium intake were evaluated using a specific questionnaire. RESULTS: Vertebral fractures were diagnosed in 40% of subjects, but densitometric osteoporosis was observed only in 13% of spine and in 25% of hip scans. Interestingly, increasing T-score threshold up to -1.5 standard deviation, the prevalence of fractured patient improved significantly, reaching 60% in both genders. Bone content was inversely correlated with glucocorticoids, while a positive correlation was found with cyclosporine A. Almost all subjects had vitamin D deficiency. CONCLUSIONS: Standard densitometric criteria are unreliable to identify bone fragility after transplantation, and a different threshold (-1.5 standard deviation) should be considered. Transplanted patients should be adequately supplemented with vitamin D, and the effects of immunosuppressant agents on bone need further investigation.

The effect of risedronate on osteogenic lineage is mediated by cyclooxygenase-2 gene upregulation.

INTRODUCTION: The purpose of this study was to evaluate the effects of risedronate (Ris) in the modulation of bone formation in rats with glucocorticoid (GC)-induced osteoporosis by histomorphometric, immunohistochemical and gene expression analyses. METHODS: We analyzed structure, turnover and microarchitecture, cyclooxygenase 2 (COX-2) levels and osteocyte apoptosis in 40 female rats divided as follows: 1) vehicle of methylprednisolone (vGC) + vehicle of risedronate (vRis); 2) Ris 5 µg/Kg + vGC; 3) methylprednisolone (GC) 7 mg/Kg + vRis; 4) GC 7 mg/Kg +Ris 5 µg/Kg. In addition, we evaluated cell proliferation and expression of COX-2 and bone alkaline phosphatase (b-ALP) genes in bone marrow cells and MLO-y4 osteocytes treated with Ris alone or in co-treatment with the selective COX-2 inhibitor NS-398 or with dexametasone. RESULTS: Ris reduced apoptosis induced by GC of osteocytes (41% vs 86%, P < 0.0001) and increased COX-2 expression with respect to controls (Immuno-Hystochemical Score (IHS): 8.75 vs 1.00, P < 0.0001). These positive effects of Ris in bone formation were confirmed by in vitro data as the viability and expression of b-ALP gene in bone marrow cells resulted increased in a dose dependent manner. CONCLUSIONS: These findings suggest a positive effect of Ris in bone formation and support the hypothesis that the up-regulation of COX-2 could be an additional mechanism of anabolic effect of Ris.

The future of stem cells in liver diseases.

Preliminary experience with clinical hepatocyte transplantation during the past decade has provided proof of concept that cell therapy can be effective for the treatment of some liver diseases. Recent progress in cell biology resulting in the isolation and characterization of hepatic stem cells and progenitor cells further increased the expectation for a new approach to the treatment of genetic and chronic liver disease. Several potential sources have been identified of hepatic stem/ progenitor cells exhibiting both differentiation towards the hepatic lineage in vitro and hepatic parenchymal repopulation with liver-specific metabolic activity in liver-injured animal models. However, a few of these results proved to be poorly reproducible in different laboratories, and it was recognized that some initial optimistic conclusions were drawn from incorrect interpretation of experimental data or from insufficient knowledge of the mechanisms involved in tissue regeneration. Moreover, only modest results have emerged so far from ongoing clinical experience involving the use of putative stem cells in liver disease. There is much need for a joined effort to concentrate the resources on a specific cell population, in order to better characterize its function, to assess its safety and to develop better focused clinical trials. In conclusion, while the biological features of stem cells still justify the hope for future clinical applications, hepatic stem cell therapy has still a long way to go from bench to bedside.

SiO(2) entrapment of animal cells: liver-specific metabolic activities in silicaoOverlaid hepatocytes.

Rat hepatocytes in a collagen-gel sandwich configuration were exposed to silicon alkoxides in a gas phase, yielding a 0.05 to 0.15 microm porous silica layer on the gel surface. Cell viability was unaffected by the procedure. After 24 h, bilirubin conjugation, ammonia removal, urea synthesis, and diazepam metabolism were unaffected by the procedure. However, both the ammonia removal rate and diazepam metabolism were increased after 48 hr, whereas urea synthesis was unaffected. These data indicate that silica overlay allows efficient metabolic activity of collagen-gel entrapped hepatocytes. The fact that the KM of bilirubin conjugation was unaffected by the presence of the silica membrane suggests that the transport of albumin-bound substrates is not decreased. The enhancement in some metabolic activities found 48 h after the entrapment procedure may be the result of favorable changes in the hepatocyte microenvironment. These characteristics might be useful for the development of organotypical bioartificial liver devices.

Hepatocyte transplantation as a treatment for glycogen storage disease type 1a.

Treatment of many inherited disorders of hepatic metabolism is still challenging. Hepatocyte transplantation was done in a 47-year-old woman who had glycogen storage disease type 1a and severe fasting hypoglycaemia. 2 billion viable hepatocytes were infused via an indwelling portal-vein catheter, followed by a triple immunosuppression regimen with mycophenolate mofetil, tacrolimus, and steroids. 9 months after transplantation, on only tacrolimus, she eats a normal diet and can fast for 7 h without experiencing hypoglycaemia. Our results show that hepatocyte transplantation might be an alternative to liver transplantation in glycogen storage disease type 1a.