Immunogenic cell death,DAMPs and anticancer therapeutics: An emerging amalgamation

Immunogenic profile of certain cancer cell death mechanisms has been transmuted by research published over a period of last few years and this change has been so drastic that a new (sub)class of apoptotic cancer cell death, redefined as ‘immunogenic apoptosis’ has started taking shape. In fact, it has been shown that this chemotherapeutic agent-specific immunogenic cancer cell death modality has the capabilities to induce ‘anticancer vaccine effect’, in vivo. These new trends have given an opportunity to combine tumour cell kill and antitumour immunity within a single paradigm, a sort of ‘holy grail’ of anticancer therapeutics. At the molecular level, it has been shown that the immunological silhouette of these cell death pathways is defined by a set of molecules called ‘damage-associated molecular patterns (DAMPs)’. Various intracellular molecules like calreticulin (CRT), heat-shock proteins (HSPs), high-mobility group box-1 (HMGB1) protein, have been shown to be DAMPs exposed/secreted in a stress agent/factor-and cell death-specific manner. These discoveries have motivated further research into discovery of new DAMPs, new pathways for their exposure/secretion, search for new agents capable of inducing immunogenic cell death and urge to solve currently present problems with this paradigm. We anticipate that this emerging amalgamation of DAMPs, immunogenic cell death and anticancer therapeutics may be the key towards squelching cancer-related mortalities, in near future.     

Adult Colorado potato beetles, Leptinotarsa decemlineata compensate for nutritional stress on oryzacystatin I-transgenic potato plants by hypertrophic behavior and over-production of insensitive proteases

Protease inhibitors have been proposed as potential control molecules that could be engineered into potato plants for developing crops resistant to the Colorado potato beetle, Leptinotarsa decemlineata, a major pest of potato and other Solanaceae. In this study, we examined the effects of feeding young female beetles with foliage from a cultivar of the "Kennebec" potato line (K52) transformed with a gene encoding oryzacystatin I (OCI), a specific cysteine proteinase inhibitor with proven activity against cathepsin H-like enzymes of larvae and adults of the potato beetle. To evaluate the insect's performance, we collected data over a 16-d postemergence period on survival, diapause incidence, foliage consumption, weight gain, and oviposition of females. Tested individuals were fed untransformed (control) and OCI-transformed foliage at two stages of potato leaf differentiation, corresponding to "low" and "high" levels of OCI expression in leaves of K52. The OCI-expressing foliage did not affect female survival (close to 100%), incidence of diapause (15-30%), relative growth rate (RGR) during postemergence growth (5-9% d(-1)) or maximum weight reached (140-160 mg). Neither did it affect female reproductive fitness as measured by preoviposition time (8-9 d), 16-d fecundity (220-290 eggs), or egg eclosion incidence (86-91%). However, nutritional stress to females feeding on OCI foliage was evident, as reflected in their lower efficiency of conversion of ingested foliage (ECI) during postemergence growth, increased foliage consumed per egg laid (up to 119% more), and adaptation of their digestive proteolytic system to the inhibitory effect of OCI. Interestingly, beetles fed foliage expressing the highest level of OCI reacted rapidly to the presence of OCI by producing OCI-insensitive proteases, and exhibiting strong hypertrophic behavior by ingestion of 2.4-2.5 times more OCI rich foliage apparently as a compensatory response for nutritional stress due to the protease inhibitor in their diet.     

Not my brother's keeper: A thought experiment for Hamilton's rule

The now popular ‘selfish gene’ view defines evolutionary fitness at the gene level - in terms of the number of gene copies residing in future generations (or propelled from previous generations). Yet, most current biology textbooks still apply the concept of fitness to the individual, where it is defined more traditionally as the number of descendants residing in future generations. The existing literature remains ambiguous regarding whether one of these concepts is more meaningful than the other, or whether they both represent legitimate, functional definitions of fitness. In support of the latter view, I present a composite perspective that recognizes the gene as evolutionarily ‘selfish’, but also the individual as a ‘selfish vehicle’ for resident genes. Hamilton's rule explains, based on genetic relatedness, why natural selection has favoured behaviours that compel individuals (as ‘donors’ of help) to act for the good of copies of their genes residing in close kin (‘recipients’). I propose however, that natural selection should particularly favour helping behaviours directed at those recipient kin who have the highest relative probability of being the vehicle for a remarkably adaptive newly mutant gene, weighted by the proportion of genes shared with the donor. According to this ‘adaptive-genetic-novelty-rescue’ (AGNR) hypothesis, these favoured vehicles for shared gene copies are more likely to involve direct descendants (e.g. offspring) than other close kin from one's collateral lineage (e.g. siblings), even when the donor (e.g. a father) shares fewer genes with an offspring (e.g. a son) than with a sibling (e.g. a brother).     

The medical utility of genomics data in neuropsychiatry: mutational genetics versus association genetics

The long anticipated ‘genetic revolution’ in neuropsychiatry has yet to have an impact on the practice of clinical medicine. Excitement in the 1980s over major genetic breakthroughs in schizophrenia and manic depression, for example, has been replaced in the late 1990s by the sobering realization that most common neuropsychiatric disorders are multifactorial. Despite considerable effort and resources, no ‘causative’ genetic variation has been identified that plays a definitive major role in any common neuropsychiatric disorder.     

Agility and search and rescue training differently affects pet dogs’ behaviour in socio-cognitive tasks

Both genetic factors and life experiences appear to be important in shaping dogs’ responses in a test situation. One potentially highly relevant life experience may be the dog's training history, however few studies have investigated this aspect so far. This paper briefly reviews studies focusing on the effects of training on dogs’ performance in cognitive tasks, and presents new, preliminary evidence on trained and untrained pet dogs’ performance in an ‘unsolvable task’. Thirty-nine adult dogs: 13 trained for search and rescue activities (S&R group), 13 for agility competition (Agility group) and 13 untrained pets (Pet group) were tested. Three ‘solvable’ trials in which dogs could obtain the food by manipulating a plastic container were followed by an ‘unsolvable’ trial in which obtaining the food became impossible. The dogs’ behaviours towards the apparatus and the people present (owner and researcher) were analysed. Both in the first ‘solvable’ and in the ‘unsolvable’ trial the groups were comparable on actions towards the apparatus, however differences emerged in their human-directed gazing behaviour. In fact, results in the ‘solvable’ trial, showed fewer S&R dogs looking back at a person compared to agility dogs, and the latter alternating their gaze between person and apparatus more frequently than pet dogs. In the unsolvable trial no difference between groups emerged in the latency to look at the person however agility dogs looked longer at the owner than both pet and S&R dogs; whereas S&R dogs exhibited significantly more barking (always occurring concurrently to looking at the person or the apparatus) than both other groups. Furthermore, S&R dogs alternated their gaze between person and apparatus more than untrained pet dogs, with agility dogs falling in between these two groups. Thus overall, it seems that the dogs’ human-directed communicative behaviours are significantly influenced by their individual training experiences.     

A case study in explanatory power: John Snow's conclusions about the pathology and transmission of cholera

In the mid-1800s, there was much debate about the origin or ‘exciting cause’ of cholera. Despite much confusion surrounding the disease, the so-called miasma theory emerged as the prevalent account about cholera’s cause. Going against this mainstream view, the British physician John Snow inferred several things about cholera’s origin and pathology that no one else inferred. Without observing the vibrio cholerae, however,—data unavailable to Snow and his colleagues—, there was no way of settling the question of what exactly was causing cholera and how, or if, it was passed on. The question then arises as to how Snow arrived at conclusions so systematically different from those of his opponents. In this paper, I want to look at Snow’s reasoning in some detail, and show that there were certain principles, explanatory power in particular, that were epistemologically important to Snow in their own right. I will show that Snow himself takes explanatory power to be an epistemic property, and makes explicit links between explanatory power and confirmation. Systematically juxtaposing Snow’s claims and his opponents’, I will show that Snow was right to tout the explanatory power of his theory, and that his conclusions about the epistemic superiority of his theory over that of the miasmatists’ were justified.     

Morphological correlates of tail length in the catarrhine sacrum

Taillessness is a distinctive synapomorphy of the Hominoidea that has implications for interpretation of the locomotor behaviors and phylogenetic affinities of the clade’s earliest members. However, difficulties persist in confidently identifying taillessness in the catarrhine fossil record, stemming largely from our limited knowledge of the anatomical features with which the tail is associated. Here, we compare the morphology of the sacrum, the sole bony link between the tail and the rest of the body, among extant tailless hominoids and a broad sample of extant cercopithecoids known to vary in tail length (i.e., ‘very short’, ‘short’, and ‘long’) in order to identify morphological correlates of tail length. We examine three features of the sacrum, including the shape of the sacrum’s caudal articular surface (CAS), the sacrocaudal articulation (SCA) angle, and the lateral expansion of the last sacral vertebra’s transverse processes. Compared with all other taxa, ‘long’-tailed cercopithecoids have significantly more circularly-shaped CASs, more acute SCA angles, and more laterally expanded transverse processes of the last sacral vertebra. Tailless hominoids have significantly more elliptically-shaped CASs and less laterally expanded transverse processes than all tailed cercopithecoids, but in the latter parameter, they only differ significantly from ‘long’-tailed cercopithecoids. Cercopithecoids with ‘short’ and ‘very short’ tails are intermediate between tailless hominoids and ‘long’-tailed cercopithecoids with respect to CAS shape and lateral expansion of the transverse processes. SCA angle distinguishes clearly among all three cercopithecoid tail length groups. The results of this study provide evidence for significant differences in sacral morphology among extant catarrhines known to differ in tail length, and have implications for making inferences about tail length and function in extinct catarrhines.     

Predator-induced changes in fluted giant clam (Tridacna squamosa) shell morphology

Predator-induced defences have been demonstrated in numerous marine molluscs, but never in giant clams (Bivalvia: Tridacnidae). Water-borne cues from the predatory crab Myomenippe hardwickii were tested for their ability to induce changes in the shell morphology, strength and growth of juvenile fluted giant clams, Tridacna squamosa. Specimens were maintained in effluent from tanks holding ‘fed crabs’, ‘starved crabs’ and ‘no crabs’. To ensure changes were due to predator cues only, food for the crabs was provided ex situ and measures were taken to minimise the prey signal. After 182 days, MANOVA identified differences in various shell parameters relating to shape and strength. CDA showed a clear change in overall morphology, with strong separation among the three treatments. Effluent from ‘fed crabs’ had a greater influence than effluent from ‘starved crabs’, possibly because the starved crabs were perceived as weaker, and thus less risk. Significantly more clams died in ‘fed crabs’ treatments (25%) and ‘starved crabs’ treatments (30%) compared to the ‘no crabs’ control (0%). This degree of mortality has not been observed in similar experiments elsewhere and represents a new challenge to interpret. We suggest that the cause is unlikely to be related to the plastic responses, but rather a result of some form of crab-associated contaminant.     

The effects of social context on the hormonal and behavioral responsiveness of human fathers

We tested first-time fathers with their 22-month old toddlers to determine whether social context variables such as pre-test absence from the child and presence of the mother affected physiological measures associated with paternal responsiveness. Heart rate and blood pressure readings as well as blood samples to determine prolactin, testosterone and cortisol levels were taken before and after the 30-min father–toddler interactions. Fathers were tested on a day when they were away from their child for several hours before testing (‘without-child’ day) and on another day where they remained with their child throughout the day (‘with-child’ day). Most measures decreased over the 30-min test period but relative decreases were context-dependent. Men maintained higher prolactin levels when they were away from their children longer before testing on the ‘without-child’ day. Cortisol levels decreased during both tests and they decreased more on the ‘with-child’ day for men who had spent more time alone with their toddler before the test. Heart-rate and diastolic (but not systolic) blood pressure decreased more on the ‘with-child’ day than on the ‘without-child’ day. Fathers' testosterone levels decreased when their partners were less involved in the interactions. Compared to men with high responsiveness ratings on both days, men whose responsiveness increased after being away from their child on the ‘without-child’ day maintained higher systolic blood pressure and had a greater decrease in testosterone levels. We conclude that context may be more important in determining fathers' physiological responses to child contact than has previously been appreciated, particularly for some individuals.     

Ion-trap mass spectrometry unveils the presence of isomeric oligosaccharides in an analyte: stage-discriminated correlation of energy-resolved mass spectrometry

Mass spectrometry, especially tandem mass spectrometry, has been widely used in the field of analytical sciences for handling biological and chemical samples. The technique resolves molecular and fragment ions based on the mass to charge ratio. Energy-resolved mass spectrometry (ERMS) further provides an activation energy-related factor in the dissociation reaction. Therefore, it is a very powerful technique that can discriminate isomeric compounds. Despite the power of ERMS, useful information cannot be obtained when an analyte contains structural isomers. Carbohydrates carry multiple chiral centers, thus oligomers of monosaccharides can form a vast number of structural isomers. We decided to use such species in our endeavors to establish a method of identifying the ‘purity’ of an analyte solely based on mass spectrometry. In the present paper, we describe a stage-discriminated spectral correlation of ERMS, which not only enables identification of the presence of contaminants in an analyte, but also provides information regarding the ‘purity’ of fragment ions.     

Reproductive behaviour of female Chorthippus biguttulus grasshoppers

Female grasshoppers of acoustically communicating species assume series of reproductive states that are associated with particular behaviours. Studies on laboratory populations of Chorthippus biguttulus (L.) revealed that females of this species lack the period of ‘passive copulatory readiness’, increase their attractiveness to males by sound production and mate multiple times before their first oviposition. In particular, female Ch. biguttulus display a period of ‘primary rejection’ after their imaginal moult during which they reject male mating attempts followed by a period of ‘active copulatory readiness’ in which they produce acoustic signals and may copulate with courting males. Female stridulation generally stimulated male mating activity and stridulating females attracted more male mating attempts than mute females in the same cage, indicating that males preferentially court females that signal ‘active copulatory readiness’. After receipt of a spermatophore, Ch. biguttulus females displayed periods of ‘secondary rejection’ followed by re-establishment of ‘active copulatory readiness’. Acoustic responses of females to male songs, an indicator of reproductive readiness, were significantly reduced until 2 days after mating and remained slightly reduced in comparison to pre-mating levels. Some females mated multiple times before their first oviposition and cycled between ‘secondary rejection’ and ‘active copulatory readiness’.     

Epigenetic mechanisms in schizophrenia

Epidemiological research suggests that both an individual's genes and the environment underlie the pathophysiology of schizophrenia. Molecular mechanisms mediating the interplay between genes and the environment are likely to have a significant role in the onset of the disorder. Recent work indicates that epigenetic mechanisms, or the chemical markings of the DNA and the surrounding histone proteins, remain labile through the lifespan and can be altered by environmental factors. Thus, epigenetic mechanisms are an attractive molecular hypothesis for environmental contributions to schizophrenia. In this review, we first present an overview of schizophrenia and discuss the role of nature versus nurture in its pathology, where ‘nature’ is considered to be inherited or genetic vulnerability to schizophrenia, and ‘nurture’ is proposed to exert its effects through epigenetic mechanisms. Second, we define DNA methylation and discuss the evidence for its role in schizophrenia. Third, we define posttranslational histone modifications and discuss their place in schizophrenia. This research is likely to lead to the development of epigenetic therapy, which holds the promise of alleviating cognitive deficits associated with schizophrenia.     

Plant and invertebrate assemblages on waste rock at Wangaloa coal mine, Otago, New Zealand

Natural regeneration on waste rock was investigated at the old Wangaloa coal mine, south-east Otago. A 450-m long waste rock stack had been created 40–50 years ago, and has had little anthropogenic intervention since. The stack is made up of a gradient of three main waste rock types, defined as ‘silt-rich’, ‘mixed’, and ‘quartz-rich’, which reflect different proportions of loess siltstone and quartz gravel conglomerate. Plant species assemblages were quantified in four 5-m² quadrats in each waste rock type. Invertebrates were heat extracted from substrate cores (7 cm diameter; depth 5 cm) collected from quadrats over an eight-week period in spring 2003. Ordination analysis showed statistically distinct plant and invertebrate assemblages had arisen on each waste rock type. Revegetation patterns were dominated by native, woody individuals on all waste rock types, particularly manuka (Leptospermum scoparium) and kanuka (Kunzea ericoides). Plant cover on ‘silt-rich’ waste rock was four-fold that on ‘quartz-rich’ waste rock. Total numbers of invertebrates were highest on ‘quartz-rich’ waste rock, but richness greatest on ‘silt-rich’ waste rock. Collembola dominated the fauna but their numbers were proportionally greatest in poorly vegetated areas. Further work is required to explain the absence of plants and invertebrates from local areas of waste rock.     

Comparative social cognition: what can dogs teach us?

Research in comparative social cognition addresses how challenges of social living have formed the cognitive structures that control behaviours involved in communication, social learning and social understanding. In contrast to the traditional psychological approach, recent investigations take both evolutionary and functional questions into account, but the main emphasis is still on the mechanisms of behaviour. Although in traditional research ‘comparative’ meant mainly comparisons between humans and other primates, ethological influences have led to a broadening of the spectrum of species under study. In this review, we evaluated how the study of dogs broadens our understanding of comparative social cognition. In the early days of ethology, dogs enjoyed considerable interest from ethologists, but during the last 20 years, dogs have rarely been studied by ethological methods. Through a complex evolutionary process, dogs became adapted for living in human society; therefore, the human environment and social setting now represents a natural ecological niche for this species. We have evidence that dogs have been selected for adaptations to human social life, and that these adaptations have led to marked changes in their communicative, social, cooperative and attachment behaviours towards humans. Until now, the study of dogs was hindered by the view that they represent an ‘artificial’ species, but by accepting that dogs are adapted to their niche, as are other ‘natural’ species, comparative investigations can be put into new light.     

Genetic Relationships of Ornamental Cultivars of Ginkgo biloba Analyzed by AFLP Techniques

Eight primer combinations that produced clear and a large number of polymorphic bands were screened from 64 EcoR I/Mse I primer combinations (Mse I fluorescent labeled). The genetic relationships of 21 ornamental cultivars of Ginkgo biloba L. from the United States of America, Holland, Japan, France, and China were analyzed. These primer combinations produced a total of 1 119 bands, 229 specific loci (including 54 absent bands, and 175 monomorphic bands). Among them, 983 polymorphic bands (PPB), accounting for 88%, were detected. The percentage of identification per primer combination was as high as 100%. The average PPB of 14 foreign cultivars was 35.86% and the average PPB of seven domestic cultivars was 31.51%. Genetic similarity coefficient (SC) among all cultivars varied from 0.4899 to 0.8499, and all cultivars were divided into the four clusters when SC was set at 0.7300. The cultivars from the same origin did not fall into the same group. The cultivars from France and China were classified into three groups. According to the comprehensive analyses based on specific loci, similarity coefficient, and clustering results, eight cultivars ‘Fastigiata’, ‘Tit’, ‘Tubifolia’, ‘Daeryinxing’, ‘Variegata’, ‘Horizontalis, ‘Pendula’, and ‘Yiyuanyeziyinxing’ were considered to be important germplasms of ornamental cultivars of Ginkgo biloba.     

The structure of interleukin-23 reveals the molecular basis of p40 subunit sharing with interleukin-12

Interleukin (IL)-23 is a recently identified member of the IL-12 family of heterodimeric cytokines that modulate subpopulations of T helper cells, and both IL-12 and IL-23 are attractive targets for therapy of autoimmune diseases. IL-23 is a binary complex of a four-helix bundle cytokine (p19) and a soluble class I cytokine receptor p40. IL-12 and IL-23 share p40 as an α-receptor subunit, yet show only 15% sequence homology between their four-helix cytokines p19 and p35, respectively, and signal through different combinations of shared receptors. In order to elucidate the structural basis of p40 sharing, we have determined a 2.3-Å crystal structure of IL-23 for comparison to the previously determined structure of IL-12. The docking mode of p19 to p40 is altered compared to p35, deviating by a ‘tilt’ and ‘roll’ that results in an altered footprint of p40 on the A and D helices of the respective cytokines. Binding of p19 to p40 is mediated primarily by an arginine residue on helix D of p19 that forms an extensive charge and hydrogen-bonding network with residues at the base of a pocket on p40. This ‘arginine pocket’ is lined with an inner shell of hydrophobic interactions that are ringed by an outer shell of polar interactions. Comparative analysis indicates that the IL-23 and IL-12 complexes ‘mimic’ the network of interactions constituting the central arginine pocket despite p19 and p35 having limited sequence homology. The majority of the structural epitopes in the two complexes are composed of unique p19 and p35 pairwise contacts with common residues on p40. Thus, while the critical hotspot is maintained in the two complexes, the majority of the interfaces are structurally distinct and, therefore, provide a basis for the therapeutic targeting of IL-12 versus IL-23 heterodimer formation despite their use of a common receptor subunit.     

Genetic and chemical characterization of an EMS induced mutation in Cucumis melo CRTISO gene

In order to broaden the available genetic variation of melon, we developed an ethyl methanesulfonate mutation library in an orange-flesh ‘Charentais’ type melon line that accumulates β-carotene. One mutagenized M₂ family segregated for a novel recessive trait, a yellow–orange fruit flesh (‘yofI’). HPLC analysis revealed that ‘yofI’ accumulates pro-lycopene (tetra-cis-lycopene) as its major fruit pigment. The altered carotenoid composition of ‘yofI’ is associated with a significant change of the fruit aroma since cleavage of β-carotene yields different apocarotenoids than the cleavage of pro-lycopene. Normally, pro-lycopene is further isomerized by CRTISO (carotenoid isomerase) to yield all-trans-lycopene, which is further cyclized to β-carotene in melon fruit. Cloning and sequencing of ‘yofI’ CRTISO identified two mRNA sequences which lead to truncated forms of CRTISO. Sequencing of the genomic CRTISO identified an A–T transversion in ‘yofI’ which leads to a premature STOP codon. The early carotenoid pathway genes were up regulated in yofI fruit causing accumulation of other intermediates such as phytoene and ζ-carotene. Total carotenoid levels are only slightly increased in the mutant. Mutants accumulating pro-lycopene have been reported in both tomato and watermelon fruits, however, this is the first report of a non-lycopene accumulating fruit showing this phenomenon.     

Salt-stress induced changes in the leaf proteome of diploid and tetraploid mandarins with contrasting Na and Cl accumulation behaviour

To understand the genotypic variation of citrus to mild salt stress, a proteomic approach has been carried out in parallel on two citrus genotypes (‘Cleopatra’ and ‘Willow leaf’ mandarins), which differ for Na⁺ and Cl⁻ accumulation, and their cognate autotetraploids (4×). Using two-dimensional electrophoresis approximately 910 protein spots were reproducibly detected in control and salt-stressed leaves of all genotypes. Among them, 44 protein spots showing significant variations at least in one genotype were subjected to mass spectrometry analysis for identification. Salt-responsive proteins were involved in several functions, including photosynthetic processes, ROS scavenging, stress defence, and signalling. Genotype factors affect the salt-responsive pattern, especially that of carbon metabolism. The no ion accumulator ‘Cleopatra’ mandarin genotype showed the highest number of salt-responsive proteins, and up-regulation of Calvin cycle-related proteins. Conversely the ion accumulator ‘Willow leaf’ mandarin showed high levels of several photorespiration-related enzymes. A common set of proteins (twelve spots) displayed higher levels in salt-stressed leaves of 2× and 4× ‘Cleopatra’ and 4× ‘Willow leaf’ mandarin. Interestingly, antioxidant enzymes and heat shock proteins showed higher constitutive levels in 4× ‘Cleopatra’ mandarin and 4× ‘Willow leaf’ mandarin compared with the cognate 2× genotype. This work provides for the first time information on the effect of 8 weeks of salt stress on citrus genotypes contrasting for ion accumulation and their cognate autotetraploids. Results underline that genetic factors have a predominant effect on the salt response, although a common stress response independent from genotype was also found.