sirolimus and sulforaphane

The pathogenesis of neurodegenerative diseases involves altered activity of proteolytic systems and accumulation of protein aggregates. Autophagy is an intracellular process in which damaged organelles and long-lived proteins are degraded and recycled for maintaining normal cellular homeostasis. Disruption of autophagic activity in neurons leads to modify the cellular homeostasis, causing deficient elimination of abnormal and toxic protein aggregates that promotes cellular stress and death. Therefore, induction of autophagy has been proposed as a reasonable strategy to help neurons to clear abnormal protein aggregates and survive. This review aims to give an overview of some of the main modulators of autophagy that are currently being studied as possible alternatives in the search of therapies that slow the progression of neurodegenerative diseases, which are incurable to date.

Topics: Animals; Autophagy; Disease Models, Animal; Food; Humans; Isothiocyanates; Lithium; Neurodegenerative Diseases; Resveratrol; Sirolimus; Spermidine; Stilbenes; Sulfoxides; Trehalose; Valproic Acid

Previous studies have demonstrated that sulforaphane (SFN) is a promising agent against osteoclastic bone destruction. However, the mechanism underlying its anti-osteoclastogenic activity is still unclear. Herein, for the first time, we explored the potential role of autophagy in SFN-mediated anti-osteoclastogenesis in vitro and in vivo. We established an osteoclastogenesis model using receptor activator of nuclear factor kappa-β ligand (RANKL)-induced RAW264.7 cells and bone marrow macrophages (BMMs). Tartrate-resistant acid phosphatase (TRAP) staining showed the formation of osteoclasts. We observed autophagosomes by transmission electron microscopy (TEM). In vitro, we found that SFN inhibited osteoclastogenesis (number of osteoclasts: 22.67 ± 0.88 in the SFN (0) group vs. 20.33 ± 1.45 in the SFN (1 μM) group vs. 13.00 ± 1.00 in the SFN (2.5 μM) group vs. 6.66 ± 1.20 in the SFN (2.5 μM) group), decreased the number of autophagosomes, and suppressed the accumulation of several autophagic proteins in osteoclast precursors. The activation of autophagy by rapamycin (RAP) almost reversed the SFN-elicited anti-osteoclastogenesis (number of osteoclasts: 22.67 ± 0.88 in the control group vs. 13.00 ± 1.00 in the SFN group vs. 17.33 ± 0.33 in the SFN+RAP group). Furthermore, Western blot (WB) analysis revealed that SFN inhibited the phosphorylation of c-Jun N-terminal kinase (JNK). The JNK activator anisomycin significantly promoted autophagy, whereas the inhibitor SP600125 markedly suppressed autophagic activation in pre-osteoclasts. Microcomputed tomography (CT), immunohistochemistry (IHC), and immunofluorescence (IF) were used to analyze the results in vivo. Consistent with the in vitro results, we found that the administration of SFN could decrease the number of osteoclasts and the expression of autophagic light chain 3 (LC3) and protect against lipopolysaccharide (LPS)-induced calvarial erosion. Our findings highlight autophagy as a crucial mechanism of SFN-mediated anti-osteoclastogenesis and show that the JNK signaling pathway participates in this process.

Topics: Animals; Autophagy; Beclin-1; Isothiocyanates; Lipopolysaccharides; MAP Kinase Signaling System; Mice; Microtubule-Associated Proteins; Models, Biological; Osteoclasts; Osteogenesis; Phosphorylation; RAW 264.7 Cells; Sirolimus; Skull; Sulfoxides

To explore the effects of 3-methyladenine (3-MA) and rapamycin (Rapa) on autophagy and uridine 5'-diphospho-glucuronosyltransferase 1A1 (UGT1A1) induced by sulforaphane (SFN) in human colon cancer Caco-2 cells.. Western blot was used to detect the expression of microtubule-associated protein 1 light chain 3 (LC3) and UGT1A1 proteins. And immunocytochemistry was employed to observe the intracellular distribution of LC3 and nuclear localization of NF-E2-related factor 2 (Nrf2). Quantitative real-time reverse transcription-polymerase chain reaction (RT-PCR) was employed to examine the mRNA expression of UGT1A1 and human pregnane X receptor (hPXR).. After the treatment of SFN, the LC3-II protein was induced in a dose and time-dependent manner. SFN-induced LC3-II protein could be attenuated and enhanced by 3-MA and Rapa respectively. In comparison with the control group, UGT1A1 mRNA levels increased significantly after the treatment of Rapa, SFN or their combination (2.4, 4.12 and 2.41 folds respectively, all P < 0.01). And the combination of SFN and Rapa possessed the highest level. UGT1A1 protein band intensity was also enhanced in three groups. There was no obvious nuclear staining of Nrf2 in control group while intense nuclear fluorescent labeling of Nrf2 could be observed in the SFN-treated groups, especially the combination group of SFN and Rapa. The hPXR mRNA levels increased significantly in the Rapa and combination groups (1.82 and 1.4 folds respectively, both P < 0.01).. The treatment of 3-MA or Rapa may attenuate or enhance SFN-induced autophagy respectively. And Rapa also potentiates SFN-induced UGT1A1 expression. The mechanism for the synergic effect of Rapa and SFN on UGT1A1 induction may be a simultaneous activation of Nrf2 and hPXR signaling pathway.

Topics: Adenine; Autophagy; Caco-2 Cells; Glucuronosyltransferase; Humans; Isothiocyanates; Sirolimus; Sulfoxides

Sulforaphane (SFN) is a compound derived from cruciferous plants. Its anticancer properties have been demonstrated both, in cancer cell lines as well as tumors in animal models. It has been shown that SFN inhibits cell proliferation, induces apoptosis, autophagy, and sensitizes cancer cells to therapies. As induction of catabolic processes is often related to perturbation in protein synthesis we aimed to investigate the impact of SFN on this process in PC-3 human prostate cancer cells. In the present study we show that SFN inhibits protein synthesis in PC-3 cells in a dose- and time-dependent manner which is accompanied by a decreased phosphorylation of mTOR substrates. Translation inhibition is independent of mitochondria-derived ROS as it is observed in PC-3 derivatives devoid of functional mitochondrial respiratory chain (Rho0 cells). Although SFN affects mitochondria and slightly decreases glycolysis, the ATP level is maintained on the level characteristic for control cells. Inhibition of protein synthesis might be a protective response of prostate cancer cells to save energy. However, translation inhibition contributes to the death of PC-3 cells due to decreased level of a short-lived protein, survivin. Overexpression of this anti-apoptotic factor protects PC-3 cells against SFN cytotoxicity. Protein synthesis inhibition by SFN is not restricted to prostate cancer cells as we observed similar effect in SKBR-3 breast cancer cell line.

Topics: Antineoplastic Agents, Phytogenic; Brassicaceae; Cell Line, Tumor; Cell Survival; Energy Metabolism; Humans; Inhibitor of Apoptosis Proteins; Isothiocyanates; Male; Mitochondria; Phosphorylation; Plant Extracts; Prostatic Neoplasms; Protein Biosynthesis; Protein Processing, Post-Translational; Protein Synthesis Inhibitors; Reactive Oxygen Species; Ribosomal Protein S6 Kinases, 70-kDa; Signal Transduction; Sirolimus; Sulfoxides; Survivin; Thiocyanates; TOR Serine-Threonine Kinases