Apoptosis induced in normal human hepatocytes by tumor necrosis factor-related apoptosis-inducing ligand

Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) has been reported to induce apoptosis in various tumor cells but not in nontransformed, normal cells. Preclinical studies in mice and nonhuman primates have shown that administration of TRAIL can induce apoptosis in human tumors, but that no cytotoxicity to normal organs or tissues is found. The susceptibility of tumor cells to TRAIL and an apparent lack of activity in normal cells has lead to a proposal to use TRAIL in cancer therapy. Here, we assessed the sensitivity of hepatocytes from rat, mouse, rhesus monkey and human livers to TRAIL-induced apoptosis. TRAIL induced apoptosis in normal human hepatocytes in culture but not in hepatocytes isolated from the other species. Human hepatocytes showed characteristic features of apoptosis, including cytoplasmic shrinkage, the activation of caspases and DNA fragmentation. Apoptosis and cell death in human hepatocytes was massive and rapid, occurring in more than 60% of the cells exposed to TRAIL within 10 hours. These results indicate that there are species differences in sensitivity to TRAIL, and that substantial liver toxicity might result if TRAIL were used in human cancer therapy.     

Chitosan sponges as tissue engineering scaffolds for bone formation

Rat calvarial osteoblasts were grown in porous chitosan sponges fabricated by freeze drying. The prepared chitosan sponges had a porous structure with a 100-200 microm pore diameter, which allowed cell proliferation. Cell density, alkaline phosphatase activity and calcium deposition were monitored for up to 56 d culture. Cell numbers were 4 x 10(6) (day 1), 11 x 10(6) (day 28) and 12 x 10(6) (day 56) per g sponge. Calcium depositions were 9 (day 1), 40 (day 28) and 48 (day 56) microg per sponge. Histological results corroborated that bone formation within the sponges had occurred. These results show that chitosan sponges can be used as effective scaffolding materials for tissue engineered bone formation in vitro.     

Microwave-accelerated energy-efficient esterification of free fatty acid with a heterogeneous catalyst

This paper shows energy-efficiency of microwave-accelerated esterification of free fatty acid with a heterogeneous catalyst by net microwave power measurement. In the reaction condition of 5 wt% sulfated zirconia and 1:20 M ratio of oil to methanol at 60°C and atmospheric pressure, more than 90% conversion of the esterification was achieved in 20 min by microwave heating, while it took about 130 min by conventional heating. Electric energy consumption for the microwave heating in this accelerated esterification was only 67% of estimated minimum heat energy demand because of significantly reduced reaction time.     

Black soldier fly (Hermetia illucens) larvae oil as an alternative fat ingredient to soybean oil in laying hen diets

ObjectiveThe objective of this study was to determine whether dietary black soldier fly (Hermetia illucens, HI) larvae oil (HILO) could serve as an alternative fat source to soybean oil (SBO) in laying hen diets.MethodsWe randomly assigned 25-week-old Hy-line Brown laying hens (n = 144) to receive (n = 6 hens/group; eight replicates) a control or an experimental diet in which SBO was replaced with 50% (50HILO) or 100% HILO (100HILO).ResultsDietary HILO did not negatively affect body weight or productive performance during the study. The eggs also had similar quality parameters, proximate composition, and cholesterol levels. However, the yolk color index was significantly higher (p<0.01) in the 100HILO than in the other groups. Dietary HILO significantly altered the composition of fatty acids (FAs) in abdominal fat and eggs. Total saturated fatty acids (SFAs) and total polyunsaturated FAs (PUFAs) were significantly increased and decreased in the 50HILO and 100HILO groups, respectively, compared with those in the control group (p<0.001 and p<0.0001, respectively). Specifically, the medium-chain FAs lauric and myristic acids were remarkably increased in the abdominal fat of laying hens fed HILO (p<0.0001), whereas only myristic acid increased in eggs (p<0.0001). Undesirable heavy metal (aluminum, fluorine, arsenic, lead, mercury, and cadmium) concentrations were below permissible limits in eggs.ConclusionWe considered that HILO could be an alternative dietary fat to SBO for laying hens with maintained productive performance and good egg quality.     

2-Methylacrylamide as a bioisoster of thiourea group for 1,3-dibenzylthioureido TRPV1 receptor antagonists

In order to replace thiourea group with the more drug-like moiety for 1,3-dibenzylthioureas having TRPV1 antagonist activity, we introduced a set of functional groups between the two aromatic rings based on bioisosteric replacement. The synthesized bioisosteres of 1,3-dibenzylthioureas were tested for their antagonist activities on TRPV1 by ⁴⁵Ca²⁺-influx assay using neonatal rat cultured spinal sensory neurons. Among the tested 14 kinds of bioisosters, 2-methylacrylamide group was the best candidate to replace thiourea group. Compound 7c, 2-methylacrylamide analog of ATC-120, showed as potent as ATC-120 in its antagonist activity. In addition, 2-methylacrylamide analog 7e having vinyl moiety showed the most potent activity with 0.022?μM of IC₅₀ value, indicating that thiourea group of 1,3-dibenzylthioureas could be replaced to 2-methylacrylamide without loss of their potencies.     

Regulation of Akt by EGF-R inhibitors,a possible mechanism of EGF-R inhibitor-enhanced TRAIL-induced apoptosis

Tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) is a type II transmembrane cytokine and a potent inducer of apoptosis. Epidermal growth factor (EGF) signaling is well known to involve in tumor survival and overexpression of EGF receptor (EGF-R) attributes to decreased responsiveness to many available therapies in cancer treatment. We investigated whether EGF-R inhibitors enhance TRAIL-induced apoptosis. We exposed A549 cells to Genistein, PD153035, and PD158780 for 12h and then treated with recombinant TRAIL protein. TRAIL alone induced 25% cell death after a 3-h treatment, but in cells pretreated with EGF-R inhibitors, TRAIL induced cell death to more than 70% after 3h treatment. Genistein enhanced TRAIL-induced apoptosis in a time- and dose-dependent manner. Western blot analyses showed that pretreatment with Genistein down-regulated the protein levels of total Akt and phosphorylated active Akt. Genistein also decreased the protein level of Bcl-XL that is regulated by Akt. These molecules are well characterized to act against induction of apoptotic cell death. Therefore, our data suggest that EGF-R inhibitor may sensitize A549 cells to TRAIL-induced apoptosis by regulating expression of these proteins. EGF-R inhibitors may play an important role in the anti-cancer activity of TRAIL protein, especially in TRAIL-resistant tumors that arise by expressing constitutively active Akt.