Reduced caloric intake and periodic fasting independently contribute to metabolic effects of caloric restriction

Caloric restriction (CR) has positive effects on health and longevity. CR in mammals implements time‐restricted (TR) feeding, a short period of feeding followed by prolonged fasting. Periodic fasting, in the form of TR or mealtime, improves metabolism without reduction in caloric intake. In order to understand the relative contribution of reduced food intake and periodic fasting to the health benefits of CR, we compared physiological and metabolic changes induced by CR and TR (without reduced food intake) in mice. CR significantly reduced blood glucose and insulin around the clock, improved glucose tolerance, and increased insulin sensitivity (IS). TR reduced blood insulin and increased insulin sensitivity, but in contrast to CR, TR did not improve glucose homeostasis. Liver expression of circadian clock genes was affected by both diets while the mRNA expression of glucose metabolism genes was significantly induced by CR, and not by TR, which is in agreement with the minor effect of TR on glucose metabolism. Thus, periodic fasting contributes to some metabolic benefits of CR, but TR is metabolically different from CR. This difference might contribute to differential effects of CR and TR on longevity.     

Assessment of the scalability of a microtiter plate system for screening of oleaginous microorganisms

Applied Microbiology and Biotechnology - Recent developments in molecular biology and metabolic engineering have resulted in a large increase in the number of strains that need to be tested,...     

Loss of ERE binding activity by estrogen receptor-alpha alters basal and estrogen-stimulated bone-related gene expression by osteoblastic cells

Estrogen receptor (ER)-alpha can signal either via estrogen response element (ERE)-mediated pathways or via alternate pathways involving protein-protein or membrane signaling. We previously demonstrated that, as compared to wild type (WT) controls, mice expressing a mutant ER-alpha lacking the ability to bind EREs (non-classical estrogen receptor knock-in (NERKI)) display significant impairments in the skeletal response to estrogen. To elucidate the mechanism(s) underlying these in vivo deficits, we generated U2OS cells stably expressing either WT ER-alpha or the NERKI receptor. Compared to cells transfected with the control vector, stable expression of ER-alpha, even in the absence of E2, resulted in an increase in mRNA levels for alkaline phosphatase (AP, by 400%, P < 0.01) and a decrease in mRNA levels for insulin growth factor-I (IGF-I) (by 65%, P < 0.001), with no effects on collagen I (col I) or osteocalcin (OCN) mRNA levels. By contrast, stable expression of the NERKI receptor resulted in the suppression of mRNA levels for AP, col I, OCN, and IGF-I (by 62, 89, 60, and 70%, P < 0.001). While E2 increased mRNA levels of AP, OCN, col I, and IGF-I in ER-alpha cells, E2 effects in the NERKI cells on AP and OCN mRNA levels were attenuated, with a trend for E2 to inhibit col I mRNA levels. In addition, E2 had no effects on IGF-I mRNA levels in NERKI cells. Collectively, these findings indicate that ERE signaling plays a significant role in mediating effects of estrogen on osteoblastic differentiation markers and on IGF-I mRNA levels.     

Hierarchical classification of microorganisms based on high‐dimensional phenotypic data

The classification of microorganisms by high‐dimensional phenotyping methods such as FTIR spectroscopy is often a complicated process due to the complexity of microbial phylogenetic taxonomy. A hierarchical structure developed for such data can often facilitate the classification analysis. The hierarchical tree structure can either be imposed to a given set of phenotypic data by integrating the phylogenetic taxonomic structure or set up by revealing the inherent clusters in the phenotypic data. In this study, we wanted to compare different approaches to hierarchical classification of microorganisms based on high‐dimensional phenotypic data. A set of 19 different species of molds (filamentous fungi) obtained from the mycological strain collection of the Norwegian Veterinary Institute (Oslo, Norway) is used for the study. Hierarchical cluster analysis is performed for setting up the classification trees. Classification algorithms such as artificial neural networks (ANN), partial least‐squared discriminant analysis and random forest (RF) are used and compared. The 2 methods ANN and RF outperformed all the other approaches even though they did not utilize predefined hierarchical structure. To our knowledge, the RF approach is used here for the first time to classify microorganisms by FTIR spectroscopy.      

Redrawing the boundary of medical expertise: medically assisted reproduction and the debate on Italian bioconstitutionalism

In 2004, the Italian Parliament passed a controversial law on medically assisted reproduction (Law 40/2004). The Law obliged clinicians to create a maximum of three embryos during one in vitro fertilization (IVF) cycle and transfer them simultaneously into the patient’s uterus. With this “three embryo” standard, the Parliament sought to secure the realization of rights of IVF embryos. Drawing on the concepts of boundary-work [Gieryn, T. F. 1983. “Boundary-Work and the Demarcation of Science from Non-Science: Strains and Interests in Professional Ideologies of Scientists.” American Sociological Review 48 (6): 781–795] and bioconstitutionalism [Jasanoff, S., ed. 2011. Reframing Rights: Bioconstitutionalism in the Genetic Age. Cambridge, MA: MIT Press.], this article explores the role that the constitutional obligations of the Italian State towards its citizens, including IVF embryos as its new “citizen subjects,” played in how it envisaged and demarcated the professional boundaries of medical expertise. It argues that the latter depended upon how it balanced its commitments to protect the rights of IVF embryos and those of adult citizens. As such, the demarcation of the jurisdictional boundaries of medical expertise, and the definition of constitutional rights, formed two sides of the same governing project.     

Disentangling two non-photochemical quenching processes in Cyclotella meneghiniana by spectrally-resolved picosecond fluorescence at 77 K

Diatoms, which are primary producers in the oceans, can rapidly switch on/off efficient photoprotection to respond to fast light-intensity changes in moving waters. The corresponding thermal dissipation of excess-absorbed-light energy can be observed as non-photochemical quenching (NPQ) of chlorophyll a fluorescence. Fluorescence-induction measurements on Cyclotella meneghiniana diatoms show two NPQ processes: qE₁ relaxes rapidly in the dark while qE₂ remains present upon switching to darkness and is related to the presence of the xanthophyll-cycle pigment diatoxanthin (Dtx). We performed picosecond fluorescence measurements on cells locked in different (quenching) states, revealing the following sequence of events during full development of NPQ. At first, trimers of light-harvesting complexes (fucoxanthin–chlorophyll a/c proteins), or FCPa, become quenched, while being part of photosystem II (PSII), due to the induced pH gradient across the thylakoid membrane. This is followed by (partial) detachment of FCPa from PSII after which quenching persists. The pH gradient also causes the formation of Dtx which leads to further quenching of isolated PSII cores and some aggregated FCPa. In subsequent darkness, the pH gradient disappears but Dtx remains present and quenching partly pertains. Only in the presence of some light the system completely recovers to the unquenched state.