Biodistribution and Efficacy Studies of the Proteasome Inhibitor BSc2118 in a Mouse Melanoma Model

Inhibition of the proteasome offers many therapeutic possibilities in inflammation as well as in neoplastic diseases. However, clinical use of proteasome inhibitors is limited by the development of resistance or severe side effects. In our study we characterized the anti-tumor properties of the novel proteasome inhibitor BSc2118. The sensitivity of tumor lines to BSc2118 was analyzed in comparison to bortezomib using crystal violet staining in order to assess cell viability. The In Vivo distribution of BSc2118 in mouse tissues was tracked by a fluorescent-modified form of BSc2118 (BSc2118-FL) and visualized by confocal microscopy. Inhibition of the 20S proteasome was monitored both in cultured cell lines and in mice, respectively. Finally, safety and efficacy of BSc2118 was evaluated in a mouse melanoma model. BSc2118 inhibits proliferation of different tumor cell lines with a similar potency as compared with bortezomib. Systemic administration of BSc2118 in mice is well tolerated, even when given in a dose of 60 mg/kg body weight. After systemic injection of BSc2118 or bortezomib similar proteasome inhibition patterns are observed within the murine organs. Detection of BSc2118-FL revealed correlation of distribution pattern of BSc2118 with inhibition of proteasomal activity in cells or mouse tissues. Finally, administration of BSc2118 in a mouse melanoma model shows significant local anti-tumor effects. Concluding, BSc2118 represents a novel low-toxic agent that might be alternatively used for known proteasome inhibitors in anti-cancer treatment.     

Mechanistic modeling of biodiesel production using a liquid lipase formulation

In this article, a kinetic model for the enzymatic transesterification of rapeseed oil with methanol using Callera? Trans L (a liquid formulation of a modified Thermomyces lanuginosus lipase) was developed from first principles. We base the model formulation on a Ping‐Pong Bi‐Bi mechanism. Methanol inhibition, along with the interfacial and bulk concentrations of the enzyme was also modeled. The model was developed to describe the effect of different oil compositions, as well as different water, enzyme, and methanol concentrations, which are relevant conditions needed for process evaluation, with respect to the industrial production of biodiesel. The developed kinetic model, coupled with a mass balance of the system, was fitted to and validated on experimental results for the fed‐batch transesterification of rapeseed oil. The confidence intervals of the parameter estimates, along with the identifiability of the model parameters were presented. The predictive capability of the model was tested for a case using 0.5% (wt. Enzyme/wt. Oil), 0.5% (wt. Water /wt. Oil) and feeding 1.5 times the stoichiometric amount of methanol in total over 24 h. For this case, an optimized methanol feeding profile that constrains the amount of methanol in the reactor was computed and the predictions experimentally validated. Monte‐Carlo simulations were then used to characterize the effect of the parameter uncertainty on the model outputs, giving a biodiesel yield, based on the mass of oil, of 90.8 ± 0.55 mass %. © 2014 American Institute of Chemical Engineers Biotechnol. Prog., 30:1277–1290, 2014     

The new life of a centenarian: signalling functions of NAD(P)

Since the beginning of the last century, seminal discoveries have identified pyridine nucleotides as the major redox carriers in all organisms. Recent research has unravelled an unexpectedly wide array of signalling pathways that involve nicotinamide adenine dinucleotide (NAD) and its phosphorylated form, NADP. NAD serves as substrate for protein modification including protein deacetylation, and mono- and poly-ADP-ribosylation. Both NAD and NADP represent precursors of intracellular calcium-mobilizing molecules. It is now beyond doubt that NAD(P)-mediated signal transduction does not merely regulate metabolic pathways, but might hold a key position in the control of fundamental cellular processes. The comprehensive molecular characterization of NAD biosynthetic pathways over the past few years has further extended the understanding of the multiple roles of pyridine nucleotides in cell biology.     

Lymphotoxin, but Not TNF, Is Required for Prion Invasion of Lymph Nodes

Neuroinvasion and subsequent destruction of the central nervous system by prions are typically preceded by a colonization phase in lymphoid organs. An important compartment harboring prions in lymphoid tissue is the follicular dendritic cell (FDC), which requires both tumor necrosis factor receptor 1 (TNFR1) and lymphotoxin β receptor (LTβR) signaling for maintenance. However, prions are still detected in TNFR1^−/− lymph nodes despite the absence of mature FDCs. Here we show that TNFR1-independent prion accumulation in lymph nodes depends on LTβR signaling. Loss of LTβR signaling, but not of TNFR1, was concurrent with the dedifferentiation of high endothelial venules (HEVs) required for lymphocyte entry into lymph nodes. Using luminescent conjugated polymers for histochemical PrP^Sc detection, we identified PrP^Sc deposits associated with HEVs in TNFR1^−/− lymph nodes. Hence, prions may enter lymph nodes by HEVs and accumulate or replicate in the absence of mature FDCs.     

Autophagy and RNA virus interactomes reveal IRGM as a common target

Several intracellular pathogens have the ability to avoid or exploit the otherwise destructive process of autophagy. RNA viruses are constantly confronted with cellular autophagy, and several of them hijack autophagy during the infectious cycle to improve their own replication. Nevertheless, our knowledge of viral molecular strategies used to manipulate autophagy remains limited. Our study allowed the identification of molecular interactions between 44 autophagy-associated proteins and 83 viral proteins belonging to five different RNA virus families. This interactome revealed that the autophagy network machinery is highly targeted by RNA viruses. Interestingly, whereas some autophagy-associated proteins are targeted by only one RNA virus family, others are recurrent targets of several families. Among them, we found IRGM as the most targeted autophagy-associated protein. Downregulation of IRGM expression prevents autophagy induction by measles virus, HCV and HIV-1, and compromises viral replication. Our work combined interactomic and analytical approaches to identify potential pathogen virulence factors targeting autophagy.     

Is there a link between blastomere contact surfaces of day 3 embryos and live birth rate?

Background

Limitations in our current knowledge of normative physiologic changes in thyroid function during the periconception window narrow our ability to establish an optimal approach to screening and diagnosis of thyroid disease in pregnant women. The objective of this study was to characterize changes in thyroid function during the transition from the pre-pregnant to pregnant state in normal fertile women.

Methods

Women (N = 60) ages 30-42 years without a history of thyroid disease, who were planning pregnancy, were observed prospectively before and during early pregnancy. Thyroid function (thyroid stimulating hormone, TSH and free thyroxine, FT4) was measured before conception and between 6 and 9 weeks gestation. Pre-pregnancy samples were analyzed for thyroid antibodies. Bivariate analyses and longitudinal curves (general estimating equation models) were used to analyze changes in thyroid function during the periconception window by antibody status.

Results

Pre-pregnancy TSH values were significantly higher than early pregnancy TSH (p < 0.001), but FT4 values did not differ (p = 0.53). TSH declined as gestational age increased (P < 0.01). Thyroid antibody positive women had a higher pre-pregnancy TSH compared to antibody negative women (p < 0.01). Periconceptional change in thyroid function was more variable among women with antibodies (p < 0.001). 50% of women with elevated pre-pregnancy TSH values (TSH > 3.0 mIU/L) had normal TSH values (TSH < 2.5 mIU/L) in pregnancy.

Conclusions

TSH values decline during the transition from pre-pregnancy to early pregnancy. The change in TSH appears to be less predictable in women with thyroid antibodies. Periconceptional changes in thyroid function should be considered in formulating prenatal thyroid screening guidelines.