Oleacein Prevents High Fat Diet-Induced Adiposity and Ameliorates Some Biochemical Parameters of Insulin Sensitivity in Mice

Oleacein is one of the most abundant polyphenolic compounds of olive oil, which has been shown to play a protective role against several metabolic abnormalities, including dyslipidemia, insulin resistance, and glucose intolerance. Herein, we investigated the effects of oleacein on certain markers of adipogenesis and insulin-resistance in vitro, in 3T3-L1 adipocytes, and in vivo in high-fat diet (HFD)-fed mice. During the differentiation process of 3T3-L1 preadipocytes into adipocytes, oleacein strongly inhibited lipid accumulation, and decreased protein levels of peroxisome proliferator-activated receptor gamma (PPARγ) and fatty acid synthase (FAS), while increasing Adiponectin levels. In vivo, treatment with oleacein of C57BL/6JOlaHsd mice fed with HFD for 5 and 13 weeks prevented the increase in adipocyte size and reduced the inflammatory infiltration of macrophages and lymphocytes in adipose tissue. These effects were accompanied by changes in the expression of adipose tissue-specific regulatory elements such as PPARγ, FAS, sterol regulatory element-binding transcription factor-1 (SREBP-1), and Adiponectin, while the expression of insulin-sensitive muscle/fat glucose transporter Glut-4 was restored in HFD-fed mice treated with oleacein. Collectively, our findings indicate that protection against HFD-induced adiposity by oleacein in mice is mediated by the modulation of regulators of adipogenesis. Protection against HFD-induced obesity is effective in improving peripheral insulin sensitivity

Oral Administration of Oleuropein and Its Semisynthetic Peracetylated Derivative Prevents Hepatic Steatosis, Hyperinsulinemia, and Weight Gain in Mice Fed with High Fat Cafeteria Diet

The high consumption of olive tree products in the Mediterranean diet has been associated with a lower incidence of metabolic disorders and cardiovascular diseases. In particular, the protective effects of olive oil have been attributed to the presence of polyphenols such as oleuropein (Ole) and its derivatives. We have synthesized a peracetylated derivative of Ole (Ac-Ole) which has shown in vitro antioxidant and growth-inhibitory activity higher than the natural molecule. In this study, male C57BL/6JOlaHsd mice were fed with a standard (std), cafeteria (caf) diet, and caf diet supplemented with Ole (0.037 mmol/kg/day) and Ac-Ole (0.025 mmol/kg/day) for 15 weeks. We observed a significant reduction in the caf diet-induced body weight gain and increase of abdominal adipose tissue. Also, Ole and Ac-Ole prevented the development of hepatic steatosis. Finally, Ole and Ac-Ole determined a lower increase of HDL and LDL-cholesterol levels and corrected caf diet-induced elevation of plasma glucose concentrations by improving insulin sensitivity. The observed beneficial properties of Ole and Ac-Ole make these compounds and in particular Ac-Ole promising candidates for a potential pharmaceutic use in metabolic disorders

Expression of Leptin Receptor and Effects of Leptin on Papillary Thyroid Carcinoma Cells

Background. Obesity has been hypothesized to contribute to the aggressiveness of thyroid cancer through the production of abnormal levels of serum adipokines. Leptin receptor (OB-R) expression has also been documented in papillary thyroid cancer (PTC). Aim. In this translational study, we analyzed in vitro the effects of leptin on the growth and migration of thyroid cancer cells (TPC-1 and K1), the molecular mechanisms underlying leptin’s action, and the influence of prolonged leptin exposure on cell response to a protein kinase inhibitor lenvatinib. The expression levels of OB-R mRNA and protein were also investigated in vivo in a series of aggressive PTCs divided into two groups based on the presence of the BRAF mutation. Results. In TPC-1 and K1 cells, prolonged treatment with leptin (500 ng/ml for 96 h) resulted in a mild increase in the proliferation (about 20% over control only in K1 cells, p<0.05) and in the migration of both cancer cell lines. Immunoblot analysis revealed a slight increase in the phosphorylation of AKT, but no effect on β-catenin and phospho-ERK expressions. The inhibitory effects of lenvatinib on the viability of both cell lines were not influenced by the leptin treatment. OB-R transcript (in fresh tissues) and proteins (in formalin-fixed and paraffin-embedded specimens) were expressed in all PTC tissues examined, with no significant differences between BRAF-mutated and BRAF-wild-type tumors. Conclusions. These results demonstrate leptin’s role in mildly increasing the aggressive phenotype of PTC cells but without influencing the action of lenvatinib. Further studies will clarify whether it is possible to target OB-R, expressed in all aggressive PTCs, as an adjuvant treatment approach for these malignancies

Human telomerase reverse transcriptase in papillary thyroid cancer: gene expression, effects of silencing and regulation by BET inhibitors in thyroid cancer cells

PurposeMutations in TERT promoter have been detected in the more aggressive papillary thyroid cancers (PTCs). To elucidate the role of TERT as an eligible molecular target in these tumors, the expression of hTERT was analyzed in a series of PTCs and the effects of both pharmacological and RNA-interference-induced hTERT silencing were investigated in two human PTC cell lines (K1 and BCPAP).MethodsThe expression levels of hTERT mRNA and protein were evaluated by real-time PCR and western blot assays, respectively. Effects of hTERT silencing on PTC cell lines were analyzed by MTT, migration and western blot assays. Pharmacological inhibition of hTERT was performed using two bromodomain and extra-terminal (BET) inhibitors, JQ1 and I-BET762.ResultshTERT expression results increased in 20 out of 48 PTCs, including tumors either positive or negative for the presence of hTERT promoter and/or BRAF mutations. In K1 and BCPAP cells, hTERT silencing determined a reduction in cell viability (50% for K1 and 70%, for BCPAP, vs control) and migration properties that were associated with a decrease of AKT phosphorylation and -Catenin expression. Moreover, hTERT mRNA levels were down-regulated by two BET inhibitors, JQ1 and I-BET762, which at the same dosage (0.5 and 5 mu M) reduced the growth of these thyroid cancer cells.ConclusionsThese findings demonstrate that hTERT may represent an excellent therapeutic target in subgroups of aggressive PTCs

Expression of YAP1 in aggressive thyroid cancer

The Hippo signal transduction pathway plays a crucial role in the control of cellular proliferation, and its deregulation is believed to be involved in neoplastic transformation [ 1 , 2 ]. A wide array of human cancers show a down-regulation of Hippo pathway, resulting in the activation of the co- transcription factors Yes-associated protein 1 (YAP1) and Transcriptional coactivator with PDZ-binding motif (TAZ). In turn, the YAP/TAZ complex increases transcription of target proteins with oncogenic activity [ 1 , 2 ]. Thus, target- ing YAP1 has been tested to arrest cancer cell proliferation [ 3 , 4 ]. Increased expression and/or nuclear accumulation of YAP1 has been described also in thyroid cancer tissues and cell lines [ 5 , 6 ]. In particular, Lee et al. found that YAP1 was overexpressed in the nucleus and cytoplasm of papil- lary (PTC) and anaplastic thyroid cancers (ATC), with a higher frequency in those carrying a V600E BRAF muta- tion [ 5 ]. By silencing YAP1 in orthotopic xenograft models of thyroid cancer, they also demonstrated an involvement of YAP1 in tumor progression and resistance to RAF kinase inhibitors [ 5 ]. An oncogenic role of YAP1, played by transactivation of RAS proteins, was also reported in other preclinical models of thyroid cancer [ 6 ]. No information is available about the expression of YAP in medullary thyroid cancer (MTC). In this work, we investigated the expression of YAP1 in a series of thyroid neoplasia, including 43 PTCs classi fi ed as low/intermediate/high risk according to ATA criteria [ 7 ] and eight lymph node metastases of PTCs (LN), extending our analysis to 15 MTCs. An additional cohort of 34 low/ intermediate risk PTCs was used to analyze the expression of two target genes activated by YAP1.The Hippo signal transduction pathway plays a crucial role in the control of cellular proliferation, and its deregulation is believed to be involved in neoplastic transformation [ 1 , 2 ]. A wide array of human cancers show a down-regulation of Hippo pathway, resulting in the activation of the co- transcription factors Yes-associated protein 1 (YAP1) and Transcriptional coactivator with PDZ-binding motif (TAZ). In turn, the YAP/TAZ complex increases transcription of target proteins with oncogenic activity [ 1 , 2 ]. Thus, target- ing YAP1 has been tested to arrest cancer cell proliferation [ 3 , 4 ]. Increased expression and/or nuclear accumulation of YAP1 has been described also in thyroid cancer tissues and cell lines [ 5 , 6 ]. In particular, Lee et al. found that YAP1 was overexpressed in the nucleus and cytoplasm of papil- lary (PTC) and anaplastic thyroid cancers (ATC), with a higher frequency in those carrying a V600E BRAF muta- tion [ 5 ]. By silencing YAP1 in orthotopic xenograft models of thyroid cancer, they also demonstrated an involvement of YAP1 in tumor progression and resistance to RAF kinase inhibitors [ 5 ]. An oncogenic role of YAP1, played by transactivation of RAS proteins, was also reported in other preclinical models of thyroid cancer [ 6 ]. No information is available about the expression of YAP in medullary thyroid cancer (MTC). In this work, we investigated the expression of YAP1 in a series of thyroid neoplasia, including 43 PTCs classi fi ed as low/intermediate/high risk according to ATA criteria [ 7 ] and eight lymph node metastases of PTCs (LN), extending our analysis to 15 MTCs. An additional cohort of 34 low/ intermediate risk PTCs was used to analyze the expression of two target genes activated by YAP1

Anti-htert sirna-loaded nanoparticles block the growth of anaplastic thyroid cancer xenograft

The high frequency of hTERT-promoting mutations and the increased expression of hTERT mRNA in anaplastic thyroid cancer (ATC) make TERT a suitable molecular target for the treatment of this lethal neoplasm. In this study, we encapsulated an anti-hTERT oligonucleotide in biocompatible nanoparticles and analyzed the effects of this novel pharmaceutical preparation in preclinical models of ATC. Biocompatible nanoparticles were obtained in an acidified aqueous solution containing chitosan, anti-hTERT oligoRNAs and poloxamer 188 as a stabilizer. The effects of these anti-hTERT -nanoparticles (Na-siTERT) were tested in vitro on ATC cell lines (CAL-62 and 8505C) and in vivo on xenograft tumors obtained by flank injection of CAL-62 cells into SCID-mice. The Na-siTERT reduced the viability and migration of CAL-62 and 8505C cells after 48 h incubation. Intra-venous administration (every 48 h for 13 days) of this encapsulated drug in mice hosting a xenograft thyroid cancer determined a great reduction in the growth of the neoplasm (about 50% vs untreated animals or mice receiving empty nanoparticles), and decreased levels of Ki67 associated with lower hTERT expression. Moreover, the treatment resulted in minimal invasion of near-by tissues and reduced the vascularity of the xenograft tumor. No signs of toxicity appeared following this treatment. Telomere length was not modified by the Na-siTERT, indicating that the inhibitory effects of neoplasm growth was independent from the enzymatic telomerase function. These findings demonstrate the potential suitability of this anti-TERT nanoparticle formulation as a novel tool for ATC treatment

Effects of Oleacein on High-Fat Diet-Dependent Steatosis, Weight Gain, and Insulin Resistance in Mice

Many reports indicate that the protective action of nutraceuticals in the Mediterranean diet, against metabolic and cardiovascular diseases, can be attributed to the action of polyphenolic components of extra-virgin olive oil (EVOO). Here, we evaluated the protective effects of oleacein, one of the most abundant secoiridoids in EVOO, on the damages/metabolic alterations caused by high-fat diet (HFD) in male C57BL/6JolaHsd mice. After 5 weeks of treatment with 20 mg/kg of oleacein, body weight, glycemia, insulinemia, serum lipids, and histologic examination of liver tissue indicated a protective action of oleacein against abdominal fat accumulation, weight gain, and liver steatosis, with improvement of insulin-dependent glucose and lipid metabolism. Both serum parameters and hepatic histologic examination were altered in mice fed with HFD. By contrast, in the animals that received oleacein, plasma glucose, cholesterol and triglyceride serum levels, and liver histology were similar to controls fed with normocaloric diet. In addition, protein levels of FAS, SREBP-1, and phospho-ERK in liver were positively modulated by oleacein, indicating an improvement in liver insulin sensitivity. In a group of obese mice, treatment with oleacein determined a light, but still significant reduction of the increase in body weight, mainly due to lesser liver steatosis enlargement, associated with reduced levels of SREBP-1 and phospho-ERK and lower levels of total serum cholesterol; in these animals, altered plasma glucose and triglyceride serum levels were not reverted by oleacein. These results indicate that HFD-related hepatic insulin resistance may be partially prevented by oral administration of oleacein, suggesting a protective role of this nutraceutical against diet-dependent metabolic alterations. Additional studies are necessary to check whether oleacein can be used as an adjuvant to improve insulin sensitivity in humans

DEPDC5 variants increase fibrosis progression in Europeans with chronic HCV infection

Chronic hepatitis C virus (HCV) infection may progress to cirrhosis and hepatocellular carcinoma (HCC). Recently, two genetic variants, DEPDC5 rs1012068 and MICA rs2596542, were associated with the onset of HCC in Asian subjects with chronic HCV infection. The aim of the present study was to analyze whether DEPDC5 and MICA genetic variants were associated with liver disease progression in Europeans with chronic HCV infection. In a Northern Italian discovery cohort (n=477), neither DEPDC5 rs1012068 nor MICA rs2596542 were associated with HCC (n=150). However, DEPDC5 rs1012068 was independently associated with cirrhosis (n=300; p=0.049). The association of rs1012068 with moderate-severe fibrosis was confirmed in an independent cross-sectional German cohort (n=415; p=0.006). Furthermore, DEPDC5 rs1012068 predicted faster fibrosis progression in a prospective cohort (n=247; p=0.027). Next, we examined the distribution of non-synonymous DEPDC5 variants in the overall cross-sectional cohort (n=912). The presence of at least one variant increased the risk of moderate/severe fibrosis by 54% (p=0.040). To understand the molecular mechanism underlying the genetic association of DEPDC5 variants with fibrosis progression, we performed in vitro studies on immortalized hepatic stellate cells (LX-2). In these cells, down-regulation of DEPDC5 resulted in increased expression of β-catenin and production of its target matrix metallopeptidase 2 (MMP2), a secreted enzyme involved in fibrosis progression. CONCLUSION: DEPDC5 variants increase fibrosis progression in Europeans with chronic HCV infection. Our findings suggest that DEPDC5 down-regulation may contribute to HCV-related fibrosis by increasing MMP2 synthesis through the β-catenin pathway