Alterations of functional connectivity of the motor cortex in Fabry disease

Objective:

To evaluate the presence of functional connectivity (FC) alterations of the motor circuits in patients with Fabry disease (FD) and their possible correlation with clinical variables with a resting-state (RS) fMRI analysis.

Methods:

In our cross-sectional study, 32 patients with FD with genetically confirmed classic diagnosis of FD (12 men, mean age 43.3 ± 12.2 years) were enrolled along with 35 healthy controls (HCs) of comparable age and sex (14 men, mean age 42.1 ± 14.5 years). RS-fMRI data were analyzed with a seed-based approach, with 2 different seeds for right and left motor cortex. Patients with FD underwent a clinical examination for the assessment of different motor functions. Correlations with clinical variables were probed with the Spearman correlation coefficient.

Results:

A reduction of FC was found in patients with FD compared to HCs between both motor cortices and 2 clusters encompassing, for each side, the caudate and lenticular nucleus (p < 5 × 10−4 and p < 10−8 for right and left motor cortex, respectively) and between the left motor cortex and dentate nuclei (p = 0.01) and Crus 1 in the right cerebellar hemisphere (p = 0.001). No significant results emerged in tests for possible correlations of FC with clinical scores.

Conclusions:

An alteration of the corticostriatal pathway is present in FD, in line with the recently suggested subclinical involvement of motor circuits in this disease. These results shed new light on the pattern of cerebral involvement in FD.

Osteoblast-conditioned medium promotes proliferation and sensitizes breast cancer cells to imatinib treatment

Inhibition of platelet-derived growth factor receptor (PDGFR) signaling restricts the growth of human breast cancer in the bone of nude mice. We hypothesized that osteoblast-secreted substances may alter the response capacity of breast cancer cells to the PDGFRs tyrosine kinase inhibitor imatinib mesylate. We found that osteoblast-conditioned medium (OCM) increases the proliferation rate of the estrogen receptor negative (ER-) MDA-MB-231 and of the ER+ MCF-7 human breast cancer cell lines and the growth-promoting effect on ER+ cells is independent from estrogen. OCM significantly improved the dose- and the time-dependent sensitivity of the tumor cells to the anti-proliferative effect of imatinib. We also found that MDA-MB-231 and MCF-7 cells express the two PDGFRs subtypes, PDGFR-alpha and PDGFR-beta, and OCM treatment increases the expression of the PDGFRs. Furthermore, imatinib inhibited the phosphorylation rate of its target tyrosine kinase receptors. We conclude that bone microenvironment, through osteoblast-secreted substances may cause estrogen-independent proliferation of breast cancer cells by a mechanism mediated by the induction of PDGFRs expression. The enhanced sensitivity of OCM-treated breast cancer cells to imatinib would justify investigation on the efficacy of imatinib in bone breast cancer metastasis.

[Guidelines for the diagnosis, prevention and treatment of osteoporosis]

The guidelines for the osteoporosis management were first drafted by a working group and then critically evaluated by the board of SIOMMMS. The most relevant points are:

DEFINITION

Osteoporosis is defined as a quantitative and qualitative deterioration of bone tissue leading to increased risk of fracture. Postmenopausal and senile osteoporosis are defined as primitive.

DIAGNOSIS

The cornerstone for the diagnosis of osteoporosis is the measurement of bone mineral density (BMD) by DXA (dual-energy X-ray absortiometry) at the femoral neck with T-score values <-2.5, following the WHO definition. Other DXA sites or technologies for measuring bone mass are also acceptable when the former is not accessible. A BMD evaluation is recommended to all women above 65 years of age. At younger age or in man the bone assessment is recommended only in subjects with specific risk factors. A control of bone mass measurement is seldom required before 2 years.

DIFFERENTIAL DIAGNOSIS

A few biochemical tests such as serum and urinary calcium, protein electrophoresis, serum creatinine and ESR are usually sufficient to exclude most secondary types of osteoporosis. The value of the so called bone turnover markers for the diagnosis and follow-up of osteoporosis remains uncertain. Several secondary forms of osteoporosis require a specific diagnostic and therapeutic management.

PREVENTION

The osteoporosis prevention should be based on the elimination of specific risk factors such as inadequate calcium and vitamin D intake, smoking and sedentary life. The use of pharmacological agents in subjects with BMD values >-2.5 is usually not justified. Pharmacological intervention: The use of drugs registered for the treatment of osteoporosis are recommended when the benefits overcome the risk. This is the case only when the risk of fracture is rather high. FRAX is recognized as a useful tool for easily estimate the long-term fracture risk. SIOMMMS with these guidelines is committed to validate and further develop this diagnostic tool.

Concerns about serum androgens monitoring during testosterone replacement treatments in hypogonadal male athletes: a pilot study

INTRODUCTION

A well-tailored testosterone replacement treatment (TRT) in male hypogonadal athletes plays a pivotal role to restore physiological performances, to reduce health risks, and to guarantee the ethic of competition. Few studies evaluated individual androgens profiles during TRT in trained individuals.

AIM

The aim of this article was to verify the efficacy in restoring eugonadal serum and urinary androgens profiles after testosterone enanthate (TE) and gel (TG) administration.

METHODS

Ten male Caucasian-trained volunteers affected by severe hypotestosteronemia (<8 nmol/L) were included. Serum androgens and urinary testosterone metabolites were evaluated, in the same subjects, before and weekly for 5 weeks after both a single intramuscular TE injection (250 mg) and during a daily administration of TG (50 mg/die of testosterone), respectively.

MAIN OUTCOME MEASURES

The main outcome measures of this article were serum total testosterone (TT), dihydrotestosterone (DHT), calculated free and bioavailable testosterone (cFT, cBioT), 17-β-estradiol, and urinary glucuronide testosterone metabolites.

RESULTS

Supraphysiological TT concentrations were observed in 50% of our volunteers until 7 days after TE and in the 4% of total samples after TG. Serum DHT was high both after TE (all volunteers on day 7 and 50% on day 14) and during TG (32% of total samples). A relatively low number of samples showed normal cFT and cBioT both after TE and TG (20-44%, respectively). Urinary metabolites were related to the type of treatment and to serum androgens profile and resulted in the normal ranges from 15% to 60% of total samples.

CONCLUSION

Besides well-known variations of mean serum TT, we showed a high percentage of serum and urinary samples with abnormal androgens, being TG safer than TE. We conclude that monitoring TRT with TT only may be inaccurate because of abnormal fluctuations of other circulating androgens. Further studies to identify the appropriate markers of eugonadism during TRT are highly warranted both in athletes and in non-athletes.

Role of vitamin K2 in bone metabolism: a point of view and a short reappraisal of the literature

Vitamin K₂ (vit K₂) belongs to a large group of fat-soluble compounds whose formulation is MK (menaquinone) (MK-2 to MK-14), that seem to be involved in different biological functions. In particular, vit K₂ has been recently recognized as efficacious and safe in treatment of bone loss, as it contributes to structural integrity of osteocalcin (OC), the major non-collagenous protein typically found in bone matrix. Several studies proved low vit K₂ intake is linked to bone loss and to increased fracture risk in both sexes. Nowadays, vit K₂ supplementation is considered a significant manner to enhance the association of calcium and vitamin D whose role on bone health is largely recognized. On the other hand, vit K₂ may be used alone or with other drugs to preserve bone quality/strength from skeletal degradation after menopause and/or in patients affected by secondary osteoporosis. In this paper, we review the most recent data about vit K₂ on skeleton.

Effects of an individualized home-based unsupervised aerobic training on body composition and physiological parameters in obese adults are independent of gender

PURPOSE

Evaluation of the effects of an individualized home-based unsupervised aerobic training on body composition, physical and physiological parameters in female and male obese adults.

METHODS

Two hundred and twenty obese adults (age 47.9 ± 12.4 years; BMI 38.0 ± 7.2 kg/m²) entered the 4-month training program. Body composition, physiological and functional capacities were assessed pre- and post-intervention. All subjects were requested to perform unsupervised aerobic training with the intensity based on heart rate, walking speed and OMNI-RPE score corresponding to the individual ventilatory threshold for at least 5 days/week.

RESULTS

After 4-month study period, 40% of patients completed the protocol, 24% had high compliance (HC) (exercise ≥ 3 days/week), while 16% had low compliance (LC) to exercise prescription (exercise < than 3 days/week). In HC group, a significant improvement of body composition variables after training was performed. Moreover, oxygen uptake and metabolic equivalent at peak significantly increased after training. Six-minute walking test (6MWT) distance significantly increased while heart rate during 6MWT was significantly lower after training. No significant differences were found in LC group between pre- and post-intervention in all variables. Interestingly, gender does not influence the effects of training.

CONCLUSIONS

Our results indicate that subjects, independent of gender, with high compliance to the aerobic training based on a new individualized method can achieve a significant reduction in weight loss and also an improvement in physical and physiological parameters. This innovative personalized prescription could be a valuable tool for exercise physiologist, endocrinologists, and nutritionists to approach and correct life style of obese subjects.

Management of glucocorticoids-induced osteoporosis: role of teriparatide

Glucocorticoids (GC)-induced osteoporosis (GIOP) is the most common cause of secondary osteoporosis, which leads to an increased fracture risk in patients. The normal bone turnover depends on a balance between osteoblasts and osteoclasts activity and GC can cause a rapid bone loss, decreasing bone formation and increasing bone resorption. The decreased bone formation is mainly due to the GC-induced apoptosis of both osteoblasts and osteocytes, while the increased bone resorption is due to the increased life-span of pre-existing osteoclasts. Bisphosphonates are clearly effective in preventing and treating GIOP but anabolic therapeutic strategies are the new promising therapeutic alternative. Experimental and clinical studies indicate that teriparatide, the active (1–34) parathyroid hormone (PTH) molecule, is efficacious for the treatment of GIOP, being able to induce an increase in bone mass in these patients. Intermittent administration of human PTH (1–34) stimulates bone formation by increasing osteoblast number. Additionally, human PTH (1–34) modulates the level and/or activity of locally produced growth factors and cytokines. Teriparatide has been demonstrated in several clinical studies to significantly decrease the incidence of fractures in patients affected by GIOP. It has recently received an indication for GIOP and its label indication has also been expanded.

Do Dietary Supplements and Nutraceuticals Have Effects on Dental Implant Osseointegration? A Scoping Review

Several factors affect dental implant osseointegration, including surgical issues, bone quality and quantity, and host-related factors, such as patients' nutritional status. Many micronutrients might play a key role in dental implant osseointegration by influencing some alveolar bone parameters, such as healing of the alveolus after tooth extraction. This scoping review aims to summarize the role of dietary supplements in optimizing osseointegration after implant insertion surgery. A technical expert panel (TEP) of 11 medical specialists with expertise in oral surgery, bone metabolism, nutrition, and orthopedic surgery performed the review following the PRISMA-ScR (Preferred Reporting Items for Systematic Reviews and Meta-Analyses Extension for Scoping Reviews) model. The TEP identified micronutrients from the "European Union (EU) Register of nutrition and health claims made on foods" that have a relationship with bone and tooth health, and planned a PubMed search, selecting micronutrients previously identified as MeSH (Medical Subject Headings) terms and adding to each of them the words "dental implants" and "osseointegration". The TEP identified 19 studies concerning vitamin D, magnesium, resveratrol, vitamin C, a mixture of calcium, magnesium, zinc, and vitamin D, and synthetic bone mineral. However, several micronutrients are non-authorized by the "EU Register on nutrition and health claims" for improving bone and/or tooth health. Our scoping review suggests a limited role of nutraceuticals in promoting osseointegration of dental implants, although, in some cases, such as for vitamin D deficiency, there is a clear link among their deficit, reduced osseointegration, and early implant failure, thus requiring an adequate supplementation.

Tadalafil modulates aromatase activity and androgen receptor expression in a human osteoblastic cell in vitro model

PURPOSE

Phosphodiesterase type-5 inhibitor (PDE5i) tadalafil administration in men with erectile dysfunction is associated with increased testosterone/estradiol ratio, leading to hypothesize a potential increased effect of androgen action on target tissues. We aimed to characterize, in a cellular model system in vitro, the potential modulation of aromatase and sex steroid hormone receptors upon exposure to tadalafil (TAD).

METHODS

Human osteoblast-like cells SAOS-2 were chosen as an in vitro model system since osteoblasts are target of steroid hormones. Cells were tested for viability upon TAD exposure, which increased cell proliferation. Then, cells were treated with/without TAD for several times to evaluate potential modulation in PDE5, aromatase (ARO), androgen (AR) and estrogen (ER) receptor expression.

RESULTS

Osteoblasts express significant levels of both PDE5 mRNA and protein. Exposure of cells to increasing concentrations of TAD (10(-8)-10(-7) M) decreased PDE5 mRNA and protein expression. Also, TAD inhibited ARO mRNA and protein expression leading to an increase in testosterone levels in the supernatants. Interestingly, TAD increased total AR mRNA and protein expression and decreased ERα, with an increased ratio of AR/ER, suggesting preferential androgenic vs estrogenic pathway activation.

CONCLUSIONS

Our results demonstrate for the first time that TAD decreases ARO expression and increases AR protein expression in human SAOS-2, strongly suggesting a new control of steroid hormones pathway by PDE5i. These findings might represent the first evidence of translational actions of PDE5i on AR, which leads to hypothesize a growing relevance of this molecule in men with prostate cancer long-term treated with TAD for sexual rehabilitation.

Relationship between individual ventilatory threshold and maximal fat oxidation (MFO) over different obesity classes in women

Objective

The use of the Individual Ventilatory Threshold (IVT), as parameter to prescribe exercise intensity in individuals with obesity, has become more frequent during the last years. This study aimed to evaluate the relationship between IVT and Maximal Fat Oxidation (MFO) in women with obesity.

Methods

Fifty-two obese female adults (age = 43.6±10.9 years; BMI = 38.5±5.2 kg/m²) were included in this study. According to the BMI classification, subjects were divided into three groups: Obese Class I (OBI, n = 16); Obese Class II (OBII, n = 20) and Obese Class III (OBIII, n = 16). All subjects performed an incremental graded exercise test to evaluate peak oxygen uptake (VO_2peak), IVT and MFO. MFO was evaluated using a stoichiometric equation. Fat max zone was determined for each subject within 10% of fat oxidation rates at MFO. For each HR, %HR_max, VO₂ and %VO_2peak variable, Pearson’s correlation test was done between IVT and MFO exercise intensity. When statistical correlation was found we used a comparative statistical analysis to assess differences between IVT and MFO. Statistical significance was set at P ≤ 0.05.

Results

For each HR, %HR_max, VO₂ and %VO_2peak variable there was a positive significant correlation (P<0.01) between IVT and MFO. No significant differences were found for HR, %HR_max, and VO₂ between IVT and MFO. %VO_2peak was significantly higher at IVT than at MFO (P = 0.03).

MFO rates were significantly higher in OBIII women than in women of the other two classes. In all subjects, IVT was within the fat max zone.

Conclusion

The use of HR and VO₂ corresponding to IVT could be a useful parameter not only to improve cardiorespiratory fitness but also to prescribe physical activity that maximize fat oxidation in obese subjects.

Effect of pre-season training phase on anthropometric, hormonal and fitness parameters in young soccer players

The aims of the study were to investigate 1) the effect of 8 weeks of PSP training on anthropometrics, salivary hormones and fitness parameters in youth soccer players, 2) the correlations between fitness and hormonal parameters, and 3) the impact of the experience of the coach and his methodology of training on these parameters. Weight, height, BMI, pubertal development (PDS), salivary Cortisol (sC), salivary Testosterone (sT), salivary sDHEAS, intermittent tests (VO_2max), and countermovement jump test (CMJ) modifications of 35 youth soccer players (age: 14±0 yrs; BMI: 20.8±1.8 k/m²) from two Italian clubs (“Lupa Frascati” -LF-; “Albalonga” -AL) were analysed. A significant (p<0.05) time by club effect was observed in sC (F_(1,31) = 9.7, ES = 1.13), sT (F_(1,31) = 4.2, ES = 0.74), CMJ (F_(1,28) = 26.5, ES = 1.94), and VO_2max (F_(1,28) = 8.5, ES = 1.10). Statistical differences (p<0.05) in weight (F_(1,32) = 25.5, ES = 0.11), sC (F_(1,31) = 32.1, ES = 1.43), sT/sC ratio (F_(1,31) = 10.1, ES = 0.97), sDHEAS/sC ratio (F_(1,31) = 6.3, ES = 0.70), and VO_2max (F_(1,28) = 64.3, ES = 1.74) were found within time factor. Between clubs, differences (p<0.05) in sC (F_(1,32) = 8.5, ES = 1.17), sT (F_(1,31) = 4.2, ES = 0.74), CMJ (F_(1,28) = 26.5, ES = 1.50), and VO_2max (F_(1,28) = 8.5, ES = 1.10) were found. CMJ was inversely correlated with sDHEAS (r = -0.38) before PSP, while Δ of CMJ showed significant correlations with Δ of sC (r = 0.43) and ΔVO_2max was inversely correlated with ΔBMI (r = -0.54) and ΔsC (r = -0.37) in all subjects. Considering each single club, ΔVO_2max showed correlations with ΔBMI (r = -0.45) in AL, while ΔCMJ showed correlations with ΔPDS (r = 0.72) in LF club. Since the PSP is often limited training time to simultaneously develop physical, technical and tactical qualities, an efficient method to distribute the training load is important in youth soccer players to increase the performance and to avoid injuries.

Circulating MicroRNAs as Biomarkers of Osteoporosis and Fragility Fractures

CONTEXT

Measurement of circulating microRNAs (miRNAs) as potential biomarkers of fragility fracture risk has recently become a subject of investigation.

OBJECTIVE

Measure by next-generation sequencing (NGS), global miRNA expression in serum samples of osteoporotic subjects vs individuals with normal bone mineral density (BMD).

DESIGN

Samples were collected from patients with different bone phenotypes and/or fragility fractures who did not receive any antiresorptive and/or bone-forming drug at the time of blood collection.

SETTING

Samples and data were collected at 7 medical centers in Italy.

PATIENTS

NGS prescreening: 50 osteoporotic patients vs 30 individuals with normal BMD. Droplet digital polymerase chain reaction (ddPCR) validation: 213 patients with different bone phenotypes, including the NGS-analyzed cohort.

RESULTS

NGS identified 5 miRNAs (miR-8085, miR-320a-3p, miR-23a-3p, miR-4497, miR-145-5p) differentially expressed in osteoporosis cases without fractures vs controls. ddPCR validation confirmed lower c-miR-23a-3p expression in osteoporotic patients, with or without fracture, than in osteopenic and normal subjects and increased c-miR-320a-3p expression in osteoporotic patients with fracture and lower expression in osteoporotic patients without fracture. ddPCR analysis showed a significantly increased expression of miR-21-5p in osteoporotic patients, with or without fracture, than in osteopenic and normal subjects, not evidenced by the NGS prescreening.

DISCUSSION

Our study confirmed levels of c-miR-23a-3p and c-miR-21-5p as able to distinguish osteoporotic patients and subjects with normal BMD. Increased levels of c-miR-320a-3p specifically associated with fractures, independently by BMD, suggesting c-miR-320a-3p as a prognostic indicator of fracture risk in osteoporotic patients, to be confirmed in prospective studies on incident fractures.

The phosphodiesterase 5 inhibitor tadalafil regulates lipidic homeostasis in human skeletal muscle cell metabolism

PURPOSE

Tadalafil seems to ameliorate insulin resistance and glucose homeostasis in humans. We have previously reported that tadalafil targets human skeletal muscle cells with an insulin (I)-like effect. We aim to evaluate in human fetal skeletal muscle cells after tadalafil or I: (i) expression profile of I-regulated genes dedicated to cellular energy control, glycolitic activity or microtubule formation/vesicle transport, as GLUT4, PPARγ, HK2, IRS-1, KIF1C, and KIFAP3; (ii) GLUT4, Flotillin-1, and Caveolin-1 localization, all proteins involved in energy-dependent cell trafficking; (iii) activation of I-targeted paths, as IRS-1, PKB/AKT, mTOR, P70/S6K. Free fatty acids intracellular level was measured. Sildenafil or a cGMP synthetic analog were used for comparison; PDE5 and PDE11 gene expression was evaluated in human fetal skeletal muscle cells.

METHODS

RTq-PCR, PCR, western blot, free fatty acid assay commercial kit, and lipid stain non-fluorescent assay were used.

RESULTS

Tadalafil upregulated I-targeted investigated genes with the same temporal pattern as I (GLUT4, PPARγ, and IRS-1 at 3 h; HK2, KIF1C, KIFAP3 at 12 h), re-localized GLUT4 in cell sites positively immune-decorated for Caveolin-1 and Flotillin-1, suggesting the involvement of lipid rafts, induced specific residue phosphorylation of IRS-1/AKT/mTOR complex in association with free fatty acid de novo synthesis. Sildenafil or GMP analog did not affect GLUT4 trafficking or free fatty acid levels.

CONCLUSION

In human fetal skeletal muscle cells tadalafil likely favors energy storage by modulating lipid homeostasis via IRS-1-mediated mechanisms, involving activation of I-targeted genes and intracellular cascade related to metabolic control. Those data provide some biomolecular evidences explaining, in part, tadalafil-induced favorable control of human metabolism shown by clinical studies.

Age-associated (cardio)metabolic diseases and cross-talk between adipose tissue and skeleton: endocrine aspects

Aged individuals continue to increase in number, and it is important to understand the pathophysiological mechanisms of age-related changes in order to develop interventions that could contribute to “successful aging”. Metabolic and hormonal factors, age-related changes in body composition, and a decline in physical activity are all involved in the tendency to lose muscle mass, to gain fat mass, and, also, to experience bone loss. Obesity, sarcopenia, and osteoporosis are important widespread health problems that lead to high prevalence of both mortality and morbidity. Indeed, during the last decades, obesity and osteoporosis have become a major health threat around the world. Aging increases the risk of developing obesity, sarcopenia, osteoporosis, and, also, cardiovascular diseases. A reduction of both bone and muscle mass with a corresponding increase of fat mass and inflammation and hormonal imbalance in the elderly lead to and may synergistically increase cardiovascular diseases. This review will focus on the relationship among these different medical situations, trying to clarify the cellular and molecular mechanisms.

Modulation of estrogen receptor levels in mouse uterus by protein kinase C isoenzymes

We have recently shown that protein kinase C (PKC) modifies estrogen receptor (ER) binding and modulates the responsiveness to estrogens in a clonal osteoblast-like cell line stably transfected with the ER. The purpose of the present study was to determine whether the interaction observed between the ER and PKC signaling in these cells occurs in additional estrogen target organs, such as the uterus. When uteri were incubated for 2 h with increasing concentrations of a kinase inhibitor (H7), ER binding was enhanced in a dose-dependent manner. Stimulation of PKC with phorbol ester reduced PKC activity levels, but increased ER binding. Interestingly, the changes in binding appeared to be due primarily to alterations in cytosolic ER levels, as binding in the nuclear fraction was minimally enhanced. When levels of ER messenger RNA were evaluated by Northern blot analysis, no differences were observed among the H7- or 12-O-tetradecanoylphorbol-13-acetate (TPA)-treated and untreated groups. Western blot analysis, however, demonstrated that levels of ER cytosolic protein in the H7-, TPA-, and staurosporine-treated groups were increased relative to those in the untreated controls. When uteri were incubated with diethylstilbestrol in the presence of either H7 or TPA, no change in cytosolic ER levels was found, suggesting that only unoccupied ERs are responsive to modulation by PKC. Western blotting of the various PKC isoforms indicated that although PKC alpha, -beta1, -betaII, -delta, and -zeta are expressed in the uterus, only PKC alpha and -beta1 are translocated from the soluble to the particulate fraction and then degraded after phorbol ester stimulation. Hence, one or both of these latter PKC isoforms may regulate cytosolic ER levels. Collectively, these data indicate that PKC may play an important role in the modulation of uterine ER levels and that PKC may exert its effect on the ER at some posttranscriptional or posttranslational step. Finally, our results show that an ER-PKC interaction occurs in a whole organ such as the uterus and that this interaction may be important in the regulation of the ER activity in a variety of estrogen-responsive tissues.

Tadalafil improves lean mass and endothelial function in nonobese men with mild ED/LUTS: in vivo and in vitro characterization

PURPOSE

Phosphodiesterase type-5 inhibitor administration in diabetic men with erectile dysfunction (ED) is associated with reduced waist circumference. We evaluated potential effects of daily tadalafil administration on body composition and investigated its possible mechanism(s) of action in C₂C₁₂ skeletal muscle cells in vitro.

METHODS

Forty-three men on stable caloric intake (mean age 48.5 ± 7; BMI 25.5 ± 0.9 kg/m²) complaining mild ED and/or low urinary tract symptoms (LUTS) were randomly assigned to receive tadalafil (TAD) 5 mg/daily (once-a-day=OAD-TAD; n = 23) or 20 mg on-demand (on-demand=OD-TAD; n = 20) for 2 months. Primary outcomes were variations of body composition measured by Dual-energy X-ray absorptiometry; secondary outcomes were ED/LUTS questionnaire scores along with hormone (testosterone, estradiol, insulin) and endothelial function (Endopat2000) variations.

RESULTS

OAD-TAD increased abdominal lean mass (p < 0.01) that returned to baseline after 2 months withdrawal. LUTS scores improved (p<0.01) in OD-TAD while ED scores improved (p < 0.01) in both groups. We found significant improvements in endothelial function (p < 0.05) that directly correlated with serum insulin (p < 0.01; r = 0.3641) and inversely correlated with estradiol levels (p < 0.01; r = 0.3655) even when corrected for potential confounders. Exposure of C₂C₁₂ cells upon increasing tadalafil concentrations (10^-7 to 10^-6 M) increased total androgen receptor mRNA and protein expression as well as myogenin protein expression after 24 and 72 h (2.8 ± 0.4-fold and 1.4 ± 0.02-fold vs. control, respectively, p < 0.05).

CONCLUSIONS

Daily tadalafil improved lean mass content in non-obese men probably via enhanced insulin secretion, estradiol reduction, and improvement of endothelial function in vivo. The in vitro increased myogenin and androgen receptor protein expression in skeletal muscle cells suggests a translational action of phosphodiesterase type-5 on this receptor.

Modulation of human estrogen receptor alpha F promoter by a protein kinase C/c-Src-dependent mechanism in osteoblast-like cells

The human estrogen receptor alpha (ERalpha) gene is driven by multiple promoters, of which the F promoter alone is found to be active in primary osteoblasts. The study was aimed at identifying new regulatory pathways affecting transcription of the receptor in this cell lineage. We generated human osteoblast-like cells, Saos-2, stably transfected with a luciferase-reporter gene downstream of the human ERalpha F promoter (Saos F-Luc), and assayed the reporter response to differentiation-related signals. Over-confluence, shown to stimulate osteoblast differentiation, caused a time-dependent increase of F-promoter activity and correlated with an inactivation of protein kinase C alpha (PKCalpha ). PKC downregulation, obtained by long-term treatment with phorbol 12-myristate 13-acetate (PMA), resulted in promoter stimulation at similar levels in sub-confluent cells. The F promoter contains a putative PMA-responsive AP-1 site, but AP-1 activation was unremarkable in over-confluent cells. Treatment with PP1, a specific inhibitor of the non-receptor tyrosine-kinase c-Src, which is a negative regulator of osteoblast differentiation, showed that the activity of this kinase inhibits the F promoter. In PP1-treated cells, F-promoter activity was not further increased by PMA. Treatment with the generic kinase inhibitor 4-dimethylaminopyridine (DMAP) resulted in a dose-dependent induction of the promoter, which matched a parallel decrease of active c-Src. The effect was c-Src dependent, as DMAP caused no further promoter induction in PP1-treated cells. Overexpression of exogenous human ERalpha resulted in modest promoter stimulation, which required the ligand-independent activator function 1 of the receptor. In murine primary osteoblasts, additional ERalpha signal was observed upon induction of F promoter. In conclusion, we demonstrated a robust PKC/c-Src-dependent and estrogen-independent mechanism modulating transcription of ERalpha in osteoblasts, probably affecting estrogen responsiveness during cell differentiation.

Protein kinase C modulates estrogen receptors in differentiated osteoblastic cells in vitro

Several reports have shown an interaction between the estrogen receptor (ER) and the protein kinase C (PKC) intracellular pathways. Data from our laboratory showed that PKC activation can modulate ER levels and responsiveness in estrogen target tissues such as uterus and bone. In particular, ROS.SMER #14 osteoblastic cells, stably transfected with the mouse ER, undergo specific morphological changes in vitro. ROS.SMER #14 cells at post-confluence express a differentiated phenotype and become unresponsive to estrogenic stimulation. Interestingly, ER mRNA and protein levels were not modified by post-confluence, but ER binding sites/cell (2500-3000/cell at subconfluence) were undetectable. Moreover, PKC activity was significantly increased in post-confluent cells. Inhibition of PKC by H7 or staurosporin (PKC inhibitors) or down-regulation by long-term treatment with 12-O-tetradecanoylphorbol-13-acetate enchanced ER binding capacity in a dose-dependent manner. Since the PKC family includes several different isoforms that play different roles in cell homeostasis, we evaluated whether specific isoenzymes were involved in this event. To address this question, Western blotting analysis was performed on both sub- and post-confluent ROS.SMER #14 cells using antibodies against different PKC isoforms. In conclusion, our preliminary data indicate that estrogen responsiveness of osteoblastic cells can be highly regulated by PKC. Finally, these data suggest that this intracellular interaction might play an important role in modulating hormonal and pharmacological responsiveness of bone tissue.

The environmental pollutant cadmium induces homeostasis alteration in muscle cells in vitro

BACKGROUND

Cadmium (Cd) is a heavy metal widely distributed throughout the environment as a result of contamination from a variety of sources. It exerts toxic effects in many tissues but scarce data are present as yet on potential effects on skeletal muscle tissue.

AIM

To evaluate the potential alteration induced by Cd in skeletal muscle cells.

MATERIALS AND METHODS

C2C12 skeletal muscle cells were treated with Cd at different times of cellular differentiation and gene expression was evaluated.

RESULTS

Exposure to Cd decreased significantly p21 mRNA expression and strongly up-regulated cyclin D1 mRNA expression in committed cells and in differentiated myotubes. Moreover, myogenin, fast MyHC-IIb and slow MyHC-I mRNAs expression were also significantly decreased both in committed cells and in myotubes. Moreover, Cd exposure induced a strong increase of Pax3, Pax7 and Myf5 mRNAs expression and stimulated an up-regulation of IL6 and TNF-α proinflammatory cytokines.

CONCLUSION

These data lead to hypothesize that environmental Cd exposure might trigger an injury-like event in muscle tissue, possibly by an estrogen receptor-mediated mechanism.

Abdominal Fat and Sarcopenia in Women Significantly Alter Osteoblasts Homeostasis In Vitro by a WNT/ β -Catenin Dependent Mechanism

Obesity and sarcopenia have been associated with mineral metabolism derangement and low bone mineral density (BMD). We investigated whether imbalance of serum factors in obese or obese sarcopenic patients could affect bone cell activity in vitro. To evaluate and characterize potential cellular and molecular changes of human osteoblasts, cells were exposed to sera of four groups of patients: (1) affected by obesity with normal BMD (O), (2) affected by obesity with low BMD (OO), (3) affected by obesity and sarcopenia (OS), and (4) affected by obesity, sarcopenia, and low BMD (OOS) as compared to subjects with normal body weight and normal BMD (CTL). Patients were previously investigated and characterized for body composition, biochemical and bone turnover markers. Then, sera of different groups of patients were used to incubate human osteoblasts and evaluate potential alterations in cell homeostasis. Exposure to OO, OS, and OOS sera significantly reduced alkaline phosphatase, osteopontin, and BMP4 expression compared to cells exposed to O and CTL, indicating a detrimental effect on osteoblast differentiation. Interestingly, sera of all groups of patients induced intracellular alteration in Wnt/ β -catenin molecular pathway, as demonstrated by the significant alteration of specific target genes expression and by altered β -catenin cellular compartmentalization and GSK3 β phosphorylation. In conclusion our results show for the first time that sera of obese subjects with low bone mineral density and sarcopenia significantly alter osteoblasts homeostasis in vitro, indicating potential detrimental effects of trunk fat on bone formation and skeletal homeostasis.

Differential characteristics of bone quality and bone turnover biochemical markers in patients with hip fragility fractures and hip osteoarthritis: results of a clinical pilot study

BACKGROUND AND AIMS

Bone density and quality alterations worsen the ability of osteoporotic bone to support prosthetic implants. The aim of our study was to evaluate potential differences in bone quality and bone turnover markers in aged individuals undergoing surgery for hip fragility fracture or hip osteoarthritis.

METHODS

Eighteen subjects with hip fragility fractures (Hip Fracture Group), 35 subjects with osteoarthritis of the hip (Hip Osteoarthritis Group) and 19 subjects with normal femoral bone mineral density (Control Group) were evaluated. Serum and urinary bone markers were assayed preoperatively in all surgical patients, and within 48 hours after fracture in the Hip Fracture, Osteoarthritis and Control groups. Histomorphometric analysis was performed on surgical samples.

RESULTS

A significant alteration in calcium and PTH serum levels with hyperparathyroidism was observed in the Hip Fracture Group compared with Hip Osteoarthritis and Control Groups. C-Terminal telopeptides of type I-collagen (CTx) and tartrate resistant-acid phosphatase (TRAP), markers of bone resorption, were increased in the Hip Fracture Group compared with both Osteoarthritis and Control Groups (CTx: p<0.0007 and p<0.0039 respectively; TRAP: p<0.002 and p<0.0007). All subjects were vitamin D3-deficient, but no differences were found among the different groups. In addition, histomorphometric data showed better maintained connectivity in the Osteoarthritis Group compared with the Hip Fracture Group (p<0.0001).

CONCLUSIONS

Our data show significant differences in bone turnover markers in patients undergoing hip prosthesis for fragility fractures, compared with patients operated for hip osteoarthritis.