Cyclic ADP-ribose as a universal calcium signal molecule in the nervous system

beta-NAD(+) is as abundant as ATP in neuronal cells. beta-NAD(+) functions not only as a coenzyme but also as a substrate. beta-NAD(+)-utilizing enzymes are involved in signal transduction. We focus on ADP-ribosyl cyclase/CD38 which synthesizes cyclic ADP-ribose (cADPR), a universal Ca(2+) mobilizer from intracellular stores, from beta-NAD(+). cADPR acts through activation/modulation of ryanodine receptor Ca(2+) releasing Ca(2+) channels. cADPR synthesis in neuronal cells is stimulated or modulated via different pathways and various factors. Subtype-specific coupling of various neurotransmitter receptors with ADP-ribosyl cyclase confirms the involvement of the enzyme in signal transduction in neurons and glial cells. Moreover, cADPR/CD38 is critical in oxytocin release from the hypothalamic cell dendrites and nerve terminals in the posterior pituitary. Therefore, it is possible that pharmacological manipulation of intracellular cADPR levels through ADP-ribosyl cyclase activity or synthetic cADPR analogues may provide new therapeutic opportunities for treatment of neurodevelopmental disorders.     

Stable and variable life‐history responses to temperature and photoperiod in the beet webworm,Loxostege sticticalis

The beet webworm, Loxostege sticticalis L. (Lepidoptera: Crambidae), unlike many temperate insects and despite its wide distribution range, has a geographically stable value of the critical photoperiod for diapause induction. It has thus been hypothesized that the species could adjust its life cycle to different climates in an alternative way, which should be reflected in geographical variation and/or environmental plasticity of some other ecophysiological trait. Three remote populations of the beet webworm were studied. The insects were reared from egg to adult at several combinations of temperature and photoperiod in order to measure development times of all the immature stages and pre‐pupal body weight, and to characterize the sensitivity of these life‐history traits to the two ecological factors. The thermal reaction norms for immature development appeared to be significantly different in the three populations. There was also a significant effect of photoperiod on development time as well as on the thermal sensitivity and lower temperature threshold for larval development. Pre‐pupae from the northernmost population were heavier and their body mass was more strongly affected by photoperiod than in the other two, but attainment of a greater weight under short‐day conditions, especially combined with higher temperatures, was common for all the three populations. Nevertheless, all the discovered geographical and environmentally induced differences in life‐history traits were very small and their adaptive significance remains problematic.     

Adipose-derived stem cells stimulate regeneration of peripheral nerves: BDNF secreted by these cells promotes nerve healing and axon growth de novo

Transplantation of adipose-derived mesenchymal stem cells (ASCs) induces tissue regeneration by accelerating the growth of blood vessels and nerve. However, mechanisms by which they accelerate the growth of nerve fibers are only partially understood. We used transplantation of ASCs with subcutaneous matrigel implants (well-known in vivo model of angiogenesis) and model of mice limb reinnervation to check the influence of ASC on nerve growth. Here we show that ASCs stimulate the regeneration of nerves in innervated mice's limbs and induce axon growth in subcutaneous matrigel implants. To investigate the mechanism of this action we analyzed different properties of these cells and showed that they express numerous genes of neurotrophins and extracellular matrix proteins required for the nerve growth and myelination. Induction of neural differentiation of ASCs enhances production of brain-derived neurotrophic factor (BDNF) as well as ability of these cells to induce nerve fiber growth. BDNF neutralizing antibodies abrogated the stimulatory effects of ASCs on the growth of nerve sprouts. These data suggest that ASCs induce nerve repair and growth via BDNF production. This stimulatory effect can be further enhanced by culturing the cells in neural differentiation medium prior to transplantation.     

Intraspecific variation of thermal reaction norms for development in insects: New approaches and prospects

The main parameters (thermal constants) characterizing the effects of constant temperatures on the duration and rate of development in ectotherms are considered. The advantages and drawbacks of the linear and nonlinear models describing the dependence of the development rate on temperature are discussed. The main patterns of interspecific variation of thermal constants in insects are described. The development of new ideas in the study of intraspecific variation of thermal reaction norms for development in insects is examined. The discrepancies in the data and their interpretation in this field are shown to result mostly from using the traditional methods of determining thermal constants. According to this method, the development rates calculated as reciprocals of the mean development times at each experimental temperature are used for regression analysis. The standard errors calculated according to this method are usually too large. Instead, a fundamentally new method is employed by the authors, according to which the individual development rates calculated for each individual are used for regression analysis of the reciprocals of the mean development times. This method reduces the standard errors of thermal constants by about an order and reveals significant differences between populations and other groups of insects. New data on intraspecific variation of the thermal reaction norms for development in Myrmica ants, the linden bug Pyrrhocoris apterus, and Calliphora blowflies are briefly described and discussed. The possible adaptive significance of these forms of intraspecific variation is discussed. The prospects of research in this new field are outlined.     

Aging exacerbates damage and delays repair of alveolar epithelia following influenza viral pneumonia

Background

Influenza virus infection causes significantly higher levels of morbidity and mortality in the elderly. Studies have shown that impaired immunity in the elderly contributes to the increased susceptibility to influenza virus infection, however, how aging affects the lung tissue damage and repair has not been completely elucidated.

Methods

Aged (16–18 months old) and young (2–3 months old) mice were infected with influenza virus intratracheally. Body weight and mortality were monitored. Different days after infection, lung sections were stained to estimate the overall lung tissue damage and for club cells, pro-SPC⁺ bronchiolar epithelial cells, alveolar type I and II cells to quantify their frequencies using automated image analysis algorithms.

Results

Following influenza infection, aged mice lose more weight and die from otherwise sub-lethal influenza infection in young mice. Although there is no difference in damage and regeneration of club cells between the young and the aged mice, damage to alveolar type I and II cells (AT1s and AT2s) is exacerbated, and regeneration of AT2s and their precursors (pro-SPC-positive bronchiolar epithelial cells) is significantly delayed in the aged mice. We further show that oseltamivir treatment reduces virus load and lung damage, and promotes pulmonary recovery from infection in the aged mice.

Conclusions

These findings show that aging increases susceptibility of the distal lung epithelium to influenza infection and delays the emergence of pro-SPC positive progenitor cells during the repair process. Our findings also shed light on possible approaches to enhance the clinical management of severe influenza pneumonia in the elderly.

Electronic supplementary material

The online version of this article (doi:10.1186/s12931-014-0116-z) contains supplementary material, which is available to authorized users.     

Behavior of subadult mountain voles of two species (<Emphasis Type=Italic>Alticola strelzowi</Emphasis> and <Emphasis Type=Italic>A. tuvinicus</Emphasis>) in the open field test

A comparative study of mobility and anxiety of subadult flat-headed and Tuva silver voles in an open field test has been performed using arenas 50 and 63 cm in diameter. It is found that individuals of both species demonstrate higher movement speed and cover longer distances, both on the periphery and in general, on the larger arena. Interspecies behavioral differences have been identified only in the arena 63 cm in diameter. Subadult flat-headed voles demonstrate higher mobility and lower anxiety in the test compared to Tuva silver voles. Hypotheses pertaining to specific features of the ecology of the two species reflected in their behavior are proposed.     

Antagonistic and insecticidal properties of soil micromycetes

It was shown that microscopic fungi isolated in plague foci had an antagonistic effect on the plague causative agent. In the majority of the cases it was associated with their insecticidal activity against plague-transmitting fleas. It is expedient to consider the relations revealed between the burrow biocenosis components in investigation of plague enzootic aspects and development of new biological insecticides for control of the infection carriers.     

Cytosine DNA-methylase of a SsoII-type from Shigella sonnei 47 cells

Shigella sonnei 47 cells were found to contain DNA-methylase SsoII which is a modifying component of the system of host specificity of SsoII. The recognition sequence (RS) of methylase SsoII is represented by a five-member palyndromic structure--5'...CCNGG...3'--with a degenerated central nucleotide. Modification of SsoII affords protection of acceptor DNA not only from SsoII type restriction, but also from other restrictases, e. g., Eco RII having an analogous RS but with a less degenerated central nucleotide pair. A simple and rapid procedure for isolation and purification of DNA-methylase ScoII, which employs hydrophobic chromatography on phenyl-Sepharose, has been developed. The enzyme preparation does not contain trace amounts of specific and nonspecific endonucleases and keeps stable on storage in 30% glycerol over a period of one year.