High Metabolic Rate Research Articles

HSP70 and their co-chaperones in the human malaria parasite P. falciparum and their potential as drug targets.

As part of their life-cycle, malaria parasites undergo rapid cell multiplication and division, with one parasite giving rise to over 20 new parasites within the course of 48 h. To support this, the parasite has an extremely high metabolic rate and level of protein biosynthesis. Underpinning these activities, the parasite encodes a number of chaperone/heat shock proteins, belonging to various families. Research over the past decade has revealed that these proteins are involved in a number of essential processes within the parasite, or within the infected host cell. Due to this, these proteins are now being viewed as potential targets for drug development, and we have begun to characterize their properties in more detail. In this article we summarize the current state of knowledge about one particular chaperone family, that of the HSP70, and highlight their importance, function, and potential co-chaperone interactions. This is then discussed with regard to the suitability of these proteins and interactions for drug development.

Body mass and cell size shape the tolerance of fishes to low oxygen in a temperature-dependent manner.

Aerobic metabolism generates 15–20 times more energy (ATP) than anaerobic metabolism, which is crucial in maintaining energy budgets in animals, fueling metabolism, activity, growth and reproduction. For ectothermic water‐breathers such as fishes, low dissolved oxygen may limit oxygen uptake and hence aerobic metabolism. Here, we assess, within a phylogenetic context, how abiotic and biotic drivers explain the variation in hypoxia tolerance observed in fishes. To do so, we assembled a database of hypoxia tolerance, measured as critical oxygen tensions (P crit) for 195 fish species. Overall, we found that hypoxia tolerance has a clear phylogenetic signal and is further modulated by temperature, body mass, cell size, salinity and metabolic rate. Marine fishes were more susceptible to hypoxia than freshwater fishes. This pattern is consistent with greater fluctuations in oxygen and temperature in freshwater habitats. Fishes with higher oxygen requirements (e.g. a high metabolic rate relative to body mass) also were more susceptible to hypoxia. We also found evidence that hypoxia and warming can act synergistically, as hypoxia tolerance was generally lower in warmer waters. However, we found significant interactions between temperature and the body and cell size of a fish. Constraints in oxygen uptake related to cellular surface area to volume ratios and effects of viscosity on the thickness of the boundary layers enveloping the gills could explain these thermal dependencies. The lower hypoxia tolerance in warmer waters was particularly pronounced for fishes with larger bodies and larger cell sizes. Previous studies have found a wide diversity in the direction and strength of relationships between P crit and body mass. By including interactions with temperature, our study may help resolve these divergent findings, explaining the size dependency of hypoxia tolerance in fish.

Mice selected for a high basal metabolic rate evolved larger guts but not more efficient mitochondria.

Intra-specific variation in both the basal metabolic rate (BMR) and mitochondrial efficiency (the amount of ATP produced per unit of oxygen consumed) has profound evolutionary and ecological consequences. However, the functional mechanisms responsible for this variation are not fully understood. Mitochondrial efficiency is negatively correlated with BMR at the interspecific level but it is positively correlated with performance capacity at the intra-specific level. This discrepancy is surprising, as theories explaining the evolution of endothermy assume a positive correlation between BMR and performance capacity. Here, we quantified mitochondrial oxidative phosphorylation activity and efficiency in two lines of laboratory mice divergently selected for either high (H-BMR) or low (L-BMR) levels of BMR. H-BMR mice had larger livers and kidneys (organs that are important predictors of BMR). H-BMR mice also showed higher oxidative phosphorylation activity in liver mitochondria but this difference can be hypothesized to be a direct effect of selection only if the heritability of this trait is low. However, mitochondrial efficiency in all studied organs did not differ between the two lines. We conclude that the rapid evolution of BMR can reflect changes in organ size rather than mitochondrial properties, and does not need to be accompanied obligatorily by changes in mitochondrial efficiency.

The Role of Uric Acid as an Antioxidant in Selected Neurodegenerative Disease Pathogenesis

Uric acid, a potent antioxidant for humans, birds, reptiles, and some primate species, is the end-product of purine degradation that is formed in the xanthine/hypoxanthine reactions catalyzed by xanthine oxidase. Associated with the evolutionary loss of urate oxidase (the enzyme that oxidizes uric acid resulting in the formation of allantoin) and resulting increase in concentrations of uric acid is a prolonged life span. Uric acid is known to scavenge peroxynitrite and other free radicals that can cause an imbalance of oxidants leading to oxidative stress. Uric acid also has a role in protecting DNA from single-strand breaks caused by free radicals in the body leading to a protective effect in neurodegenerative diseases. The brain is particularly vulnerable to oxidative stress as it is considered an ‘expensive tissue’ with a particularly high metabolic rate and comparatively increased utilization of oxygen. Brain tissue is also high in unsaturated lipids, which makes it more susceptible to free radical damage. Oxidative stress is thus linked to the pathogenesis of neurodegenerative diseases and also ischemic brain injury. In this review, we summarize the function of uric acid in alleviating oxidative damage and providing protection to neural cells during injury and disease.

Do E2 and P4 contribute to the explained variance in core temperature response for trained women during exertional heat stress when metabolic rates are very high?

PurposeWomen remain underrepresented in the exercise thermoregulation literature despite their participation in leisure-time and occupational physical activity in heat-stressful environments continuing to increase. Here, we determined the relative contribution of the primary ovarian hormones (estrogen [E2] and progesterone [P4]) alongside other morphological (e.g., body mass), physiological (e.g., sweat rates), functional (e.g., aerobic fitness) and environmental (e.g., vapor pressure) factors in explaining the individual variation in core temperature responses for trained women working at very high metabolic rates, specifically peak core temperature (Tpeak) and work output (mean power output).MethodsThirty-six trained women (32 ± 9 year, 53 ± 9 ml·kg−1·min−1), distinguished by intra-participant (early follicular and mid-luteal phases) or inter-participant (ovulatory vs. anovulatory vs. oral contraceptive pill user) differences in their endogenous E2 and P4 concentrations, completed a self-paced 30-min cycling work trial in warm–dry (2.2 ± 0.2 kPa, 34.1 ± 0.2 °C, 41.4 ± 3.4% RH) and/or warm–humid (3.4 ± 0.1 kPa, 30.2 ± 1.2 °C, 79.8 ± 3.7% RH) conditions that yielded 115 separate trials. Stepwise linear regression was used to explain the variance of the dependent variables.ResultsModels were able to account for 60% of the variance in Tpeak (overline{R }2: 41% core temperature at the start of work trial, overline{R }2: 15% power output, overline{R }2: 4% [E2]) and 44% of the variance in mean power output (overline{R }2: 35% peak aerobic power, overline{R }2: 9% perceived exertion).ConclusionE2 contributes a small amount toward the core temperature response in trained women, whereby starting core temperature and peak aerobic power explain the greatest variance in Tpeak and work output, respectively.

Recycling of Mediterranean Fruit Fly Rearing Waste by Black Soldier Fly, Hermetia illucens

PurposeObjective of this study is the valorisation of mass rearing waste of fruit flies from sterile insect technique facilities by black soldier flies into high quality and quantity products as a sustainable utilisation concept.MethodsDifferent ratios of medfly rearing waste in hen feed were used for rearing black solder fly (BSF) larvae. The growth rate and insect survival were determined. Moreover, the mass gains were determined and bioconversion rates were assessed. Furthermore, the nutritional compositions of BSF pupae were analysed to evaluate the product quality.ResultsThe omnivorous BSF larvae were highly efficient at converting digested waste into body mass as compared to the control treatment (hen feed). High weight of pre-pupae was recorded for all experimental diets. The efficacy of larvae to reach pupae ranged from 92.5 to 98.5%, while the efficacy of pupae to reach adults ranged from 81.7 to 89.0%. All experimental diets exhibited high rates of prepupal weight, metabolism and efficiency of conversion of digested food. A nutritional analysis revealed that the protein and fat contents were high, while the bioaccumulation of heavy metals was low,ConclusionMedfly rearing waste is a potential feed ingredient for the production of BSF pre-pupae and could be applied to valorise this rearing waste into high-value feed.Graphical

Temperature increases induce metabolic adjustments in the early developmental stages of bigfin reef squid (Sepioteuthis lessoniana)

Climate changes, such as extreme temperature shifts, can have a direct and significant impact on animals living in the ocean system. Ectothermic animals may undergo concerted metabolic shifts in response to ambient temperature changes. The physiological and molecular adaptations in cephalopods during their early life stages are largely unknown due to the challenge of rearing them outside of a natural marine environment. To overcome this obstacle, we established a pelagic bigfin reef squid (Sepioteuthis lessoniana) culture facility, which allowed us to monitor the effects of ambient thermal elevation and fluctuation on cephalopod embryos/larvae. By carefully observing embryonic development in the breeding facility, we defined 23 stages of bigfin reef squid embryonic development, beginning at stage 12 (blastocyst; 72 h post-egg laying) and continuing through hatching (~1 month post-egg laying). Since temperature recordings from the bigfin reef squid natural habitats have shown a steady rise over the past decade, we examined energy substrate utilization and cellular/metabolic responses in developing animals under different temperature conditions. As the ambient temperature increased by 7 °C, hatching larvae favored aerobic metabolism by about 2.3-fold. Short-term environmental warming stress inhibited oxygen consumption but did not affect ammonium excretion in stage (St.) 25 larvae. Meanwhile, an aerobic metabolism-related marker (CoxI) and a cellular stress-responsive marker (HSP70) were rapidly up-regulated upon acute warming treatments. In addition, our simulations of temperature oscillations mimicking natural daily rhythms did not result in significant changes in metabolic processes in St. 25 animals. As the ambient temperature increased by 7 °C, referred to as heatwave conditions, CoxI, HSP70, and antioxidant molecule (SOD) were stimulated, indicating the importance of cellular and metabolic adjustments. As with other aquatic species with high metabolic rates, squid larvae in the tropical/sub-tropical climate zone undergo adaptive metabolic shifts to maintain physiological functions and prevent excessive oxidative stress under environmental warming.

DNA damage response in neurodevelopment and neuromaintenance.

The central nervous system is particularly susceptible to DNA repair deficiency, which renders a variety of neurodevelopmental and neurodegenerative disorders in humans. It is generally believed that DNA damage occurs upon repetitive replication and oxidative stress in highly proliferating neuroprogenitor cells (NPs), or due to high rates of metabolism and active neuronal activity in terminally differentiated neurons. DNA double-stranded breaks (DSBs) and single-stranded breaks (SSBs) constitute the most prevalent forms of DNA damage, which can result in neuronal apoptosis if unrepaired. Despite these notions, there are still gaps in our knowledge regarding the mechanism and specificity of DNA damage and repair in the neural development and the homeostasis of neural tissues. Recent studies have identified recurrent DSBs within neuronal long genes in NPs and 'programmed' SSBs in neuronal activity genes. However, the physiological function of these DNA breakages in the nervous system has not been so far explored. In this review, we summarise the recent advances in the field of DNA damage and DNA repair in neural development and neuropathies.

Management and Stimulation of High Metabolic Rates of Biomes to Effectively Remediate Mine Drainage

Drainages from mining operations frequently contain elevated levels of contaminants of concern (CoC). Indigenous adapted bacterial communities are characterized and the ability to reduce many CoC is showcased in different treatment implementations. Each contaminated site consists of a distinct prokaryotic community that in turn requires a specific C:N:P balanced environment to contribute to site remediation. This balanced bioremedial strategy is managed both for in situor fix-filmed bioreactors, using electron donor selection and ratios, redox potential, and hydraulic retention times. These communities can effectively treat elevated levels of hexavalent chromium (10 mg/L), nitrate (110 mg/L), and sulfate (1 250 mg/L) in a one-pot balanced system. Doi: 10.28991/HEF-2022-03-02-06 Full Text: PDF

Fossil biomolecules reveal an avian metabolism in theancestral dinosaur.

Birds and mammals independently evolved the highest metabolic rates among living animals1. Their metabolism generates heat that enables active thermoregulation1, shaping the ecological niches they can occupy and their adaptability to environmental change2. The metabolic performance of birds, which exceeds that of mammals, is thought to have evolved along their stem lineage3-10. However, there is no proxy that enables the direct reconstruction of metabolic rates from fossils. Here we use in situ Raman and Fourier-transform infrared spectroscopy to quantify the in vivo accumulation of metabolic lipoxidation signals in modern and fossil amniote bones. We observe no correlation between atmospheric oxygen concentrations11 and metabolic rates. Inferred ancestral states reveal that the metabolic rates consistent with endothermy evolved independently in mammals and plesiosaurs, and are ancestral to ornithodirans, with increasing rates along the avian lineage. High metabolic rates were acquired in pterosaurs, ornithischians, sauropods and theropods well before the advent of energetically costly adaptations, such as flight in birds. Although they had higher metabolic rates ancestrally, ornithischians reduced their metabolic abilities towards ectothermy. The physiological activities of such ectotherms were dependent on environmental and behavioural thermoregulation12, in contrast to the active lifestyles of endotherms1. Giant sauropods and theropods were not gigantothermic9,10, but true endotherms. Endothermy in many Late Cretaceous taxa, in addition to crown mammals and birds, suggests that attributes other than metabolism determined their fate during the terminal Cretaceous mass extinction.

Morphological and histological study of respiratory system of rabbits (Oryctolagus cuniculus)

The rabbits are considered small mammals that had, in comparison to big animals, they have a high metabolic rate and oxygen requirement. Because the larynx is located at a high angle to the oropharynx, it may immediately access the nasopharynx of rabbits categorized as nose breathers. The lungs were symmetrical in size, with the right lung being more prominent than the left and situated at the trachea's bottom. The trachea is located between the left and right bronchus. Twenty rabbits were transported to the laboratory, and by the appropriate laboratory, the instrument opened the thoracic cavity, and also the organs were filmed while the respiratory organs were removed. Due to the heart interposition and its left deviation, the left lung in rabbits is smaller than the right lung, which has just three lobes. The lungs also lack septa. The trachea is separated into two bronchi, the last of which is branched into tiny bronchioles. Achieve a histological and morphological description of rabbits' respiratory tract because the rabbits are valuable models in respiratory research due to their respiratory hyperresponsiveness, which resembles asthma in humans. The larynx is located lower than the oropharynx, where it may directly access the nasopharynx, and the rabbits are nasal breathers. The primary respiratory organs of rabbits are the left and right lung, trachea and bronchi, as in humans and rats. Still, it is supported by double cartilage in the conducting portion of the respiratory system. Keywords. Respiratory system, Oryctolagus cuniculus.

Abalone under moderate heat stress have elevated metabolic rates and changes to digestive enzyme activities

Abalone around the world are subject to increasing frequency of marine heatwaves, yet we have a limited understanding of how acute high temperature events impact the physiology of these commercially and ecologically important species. This study examines the impact of a 5 °C temperature increase over ambient conditions for six weeks on the metabolic rates, digestive enzyme activities in the digestive gland, and digestive efficiency of Red Abalone (Haliotis rufescens) and Pāua (H. iris) on their natural diets. We test the hypothesis that abalone digestive function can keep pace with this increased metabolic demand in two separate experiments, one for each species. H. iris had higher food intake in the heat treatment. Both species had higher metabolic rates in the heat treatment with Q10 = 1.73 and Q10 = 2.46 for H. rufescens and H. iris, respectively. Apparent organic matter digestibility, protein digestibility, and carbohydrate digestibility did not differ between the heat treatment and the ambient (control) treatment in either experiment. H. rufescens exhibited higher maltase, alanine-aminopeptidase, and leucine-aminopeptidase activities in the heat treatment. Amylase, β-glucosidase, trypsin, and alkaline phosphatase activities in the digestive gland tissue did not differ between temperature treatments. H. iris exhibited lower amylase and β-glucosidase activities in the heat treatment, while maltase, trypsin, leucine-aminopeptidase, and alkaline phosphatase activities did not differ between treatments. We conclude that over six weeks of moderate heat stress both abalone species were able to maintain digestive function, but achieved this maintenance in species-specific ways.

Material and Structural Functionalization of Knitted Fabrics for Sportswear.

Comfort is an important quality criterion, especially for sportswear. It influences well-being, performance and efficiency. The necessary dissipation of heat and air flow, at high metabolic rates, must be designed and planned in advance. The influence of structure, density, mass and thickness of fabric were considered as well as yarn material composition, yarn linear density, yarn evenness and yarn hairiness. The influence of the mentioned parameters on thermal properties and air permeability was calculated. From the correlation analysis, it can be concluded that yarn’s linear density, yarn short fibers hairiness, and mass per unit area of knitted fabric has the greatest impact on heat resistance. The yarn linear density, the yarn hairiness of the longer protruding fibers, and the thickness of the knitted fabric have the greatest impact on air permeability. A statistically significant model of multiple linear regression equations was offered to predict the thermal comfort of knitted fabric.

Transcriptomic signals of mitochondrial dysfunction and OXPHOS dynamics in fast-growth chicken.

IntroductionBirds are equipped with unique evolutionary adaptations to counter oxidative stress. Studies suggest that lifespan is inversely correlated with oxidative damage in birds. Mitochondrial function and performance are critical for cellular homeostasis, but the age-related patterns of mitochondrial gene expression and oxidative phosphorylation (OXPHOS) in birds are not fully understood. The domestic chicken is an excellent model to understand aging in birds; modern chickens are selected for rapid growth and high fecundity and oxidative stress is a recurring feature in chicken. Comparing fast- and slow-growing chicken phenotypes provides us an opportunity to disentangle the nexus of oxidative homeostasis, growth rate, and age in birds.Methods and ResultsWe compared pectoralis muscle gene expression patterns between a fast and a slow-growing chicken breed at 11 and 42 days old. Using RNAseq analyses, we found that mitochondrial dysfunction and reduced oxidative phosphorylation are major features of fast-growth breast muscle, compared to the slow-growing heritage breed. We found transcriptomic evidence of reduced OXPHOS performance in young fast-growth broilers, which declined further by 42 days.DiscussionOXPHOS performance declines are a common feature of aging. Sirtuin signaling and NRF2 dependent oxidative stress responses support the progression of oxidative damage in fast-growth chicken. Our gene expression datasets showed that fast growth in early life places immense stress on oxidative performance, and rapid growth overwhelms the OXPHOS system. In summary, our study suggests constraints on oxidative capacity to sustain fast growth at high metabolic rates, such as those exhibited by modern broilers.

Rescue effects of insulin on the cytotoxic effects of bitter melon extract in the human breast cancer cells

Bitter melon extract (BME) is known to inhibit breast cancer cells proliferation. Due to the high metabolic rate of cancer cells, we hypothesized that low glucose levels are detrimental to cell survivability and that BME exerts a cytotoxic effect by altering the ability of a cell to utilize glucose. Through this study, we seek to investigate if insulin is capable of mitigating the cytotoxic effects of BME and provide a “rescue effect”.Fresh bitter melons were purchased from an Asian grocery store and the extract (BME) was prepared, centrifuged, and filter sterilized. The MCF‐7 cells were cultured in the DMEM medium (normal or low glucose) with either 1% or 2 % BME (v/v) and in the presence or absence of insulin at various doses [50ng/mL, 100ng/mL, 200ng/mL]. After culturing cells for 24 hours in standard DMEM complete medium, BME and insulin were added to corresponding wells and pictures of cultures were taken every 24 hours for 2 days. After the 2 days, cell viability was then assessed using an MTT colorimetric assay at 620 nm.BME dose‐dependently inhibited MCF‐7 cell viability. Insulin demonstrated a rescue effect and increased the cell viability despite the addition of BME. Insulin also dose‐dependently enhanced MCF‐7 cell viability to an extent when added alone. Following were the % absorbance values with increasing doses of insulin. All values are relative to control (without any addition of BME or Insulin) considered as 100% and corrected for absorbance of DMEM alone; [DMEM only – 38.33%, 1% BME – 34.33%, 0% BME + 200ng Insulin – 49.87%, 1% BME + 50ng Insulin – 39.53%, 1% BME + 100ng Insulin – 39.97%, 1% BME + 200ng Insulin – 41.70%]. The 1% BME (bitter melon extract) is the positive control in our studies as our lab have found BME to be toxic to MCF‐7 cells. The same trial was repeated with 2% BME in order to better visualize the cytotoxic effects of BME and further demonstrate the subsequent rebound in cell viability following addition of insulin. All values are relative to control (without any addition of BME or Insulin) considered as 100% and corrected for absorbance of DMEM alone; [DMEM only – 58.87%, 2% BME – 17.07%, 0% BME + 200ng Insulin – 63.97%, 2% BME + 50ng Insulin – 55.70%, 2% BME + 100ng Insulin – 55.43%, 2% BME + 200ng Insulin – 59.30%].When we treated cells with increasing doses of insulin, an enhanced rescue effect was seen as reflected by the increasing absorbance values. We further tested the effects of BME and insulin by culturing the cells in low glucose DMEM. The raw data is included in the abstract due to space limitation.Our data indicates the addition of insulin is capable of rescuing cells from the cytotoxic effects of BME. Insulin seems to be capable of mitigating the cytotoxic effects of BME and, in some cases, even enhancing the viability of cells despite the prior treatment with BME. The relatively diminished rescue effect with 200ng of insulin and 2% BME may be due to the inherent strain the cells were already experiencing with BME. The high dose of insulin, coupled with the strain of attempting to replicate in sub‐optimal conditions, may have led to cells that were incapable of meeting the metabolic demand placed by the large dose of insulin and subsequent influx of glucose. Further study may be warranted to discover the threshold of benefit that insulin can provide and amount of glucose necessary for, or detrimental to, cell survival.

Estimating RNA dynamics using one time point for one sample in a single-pulse metabolic labeling experiment

BackgroundOver the past decade, experimental procedures such as metabolic labeling for determining RNA turnover rates at the transcriptome-wide scale have been widely adopted and are now turning to single cell measurements. Several computational methods to estimate RNA synthesis, processing and degradation rates from such experiments have been suggested, but they all require several RNA sequencing samples. Here we present a method that can estimate those three rates from a single sample.MethodsOur method relies on the analytical solution to the Zeisel model of RNA dynamics. It was validated on metabolic labeling experiments performed on mouse embryonic stem cells. Resulting degradation rates were compared both to previously published rates on the same system and to a state-of-the-art method applied to the same data.ResultsOur method is computationally efficient and outputs rates that correlate well with previously published data sets. Using it on a single sample, we were able to reproduce the observation that dynamic biological processes tend to involve genes with higher metabolic rates, while stable processes involve genes with lower rates. This supports the hypothesis that cells control not only the mRNA steady-state abundance, but also its responsiveness, i.e., how fast steady state is reached. Moreover, degradation rates obtained with our method compare favourably with the other tested method.ConclusionsIn addition to saving experimental work and computational time, estimating rates for a single sample has several advantages. It does not require an error-prone normalization across samples and enables the use of replicates to estimate uncertainty and assess sample quality. Finally the method and theoretical results described here are general enough to be useful in other contexts such as nucleotide conversion methods and single cell metabolic labeling experiments.

Ileal microbial composition in genetically distinct chicken lines reared under normal or high ambient temperatures

BackgroundHeat stress (HS) has negative effects on poultry productivity, health and welfare resulting in economic losses. Broiler chickens are particularly susceptible to HS due to their high metabolic rate and rapid growth. The commensal intestinal bacterial populations have an important physiological role in the host and could ameliorate the negative effect of HS on the host. Thus, the aim of this study was to compare changes in the ileal (IL) microbiota in four different broiler lines during HS.ResultsDay-old broiler chicks from Giant Jungle Fowl (JF), Athens Canadian Random Bred (ACRB), 1995 Random Bred (L1995), and Modern Random Bred (L2015) lines were raised under thermoneutral (TN) conditions until day (d) 28. On d 29 birds were subjected to TN (24 °C) or chronic cyclic HS (8 h/d, 36 °C) condition till d 56. On d 56 two birds per pen were euthanized, and IL luminal content (IL-L) and mucosal scrapings (IL-M) were collected for bacterial DNA isolation. Libraries were constructed using V3–V4 16S rRNA primers and sequenced using MiSeq. DNA sequences were analyzed using QIIME2 platform and SILVA 132 database for alpha and beta diversity, and taxonomic composition, respectively. Functional property of microbiota was predicted using the PICRUSt 2 pipeline and illustrated with STAMP software. Shannon index was significantly elevated in IL-M under HS. β-diversity PCoA plots revealed separation of microbial community of L2015-TN from JF-TN, JF-HS, ACRB-TN, and ACRB-HS in the IL-M. PERMANOVA analysis showed a significant difference between microbial community of L1995-HS compared to ACRB-HS and JF-TN, L1995-TN compared to ACRB-HS and JF-TN, L2015-HS compared to ACRB-HS and ACRB-TN, L2015-HS compared to JF-TN, L2015-TN compared to ACRB-HS and JF-TN, and ACRB-HS compared to JF-TN in the IL-L. The impact of HS on microbial composition of IL-M was more prominent compared to IL-L with 12 and 2 taxa showing significantly different relative abundance, respectively. Furthermore, differences in microbiota due to the genetic line were more prominent in IL-M than IL-L with 18 and 8 taxa showing significantly different relative abundance, respectively. Unlike taxonomy, predicted function of microbiota was not affected by HS. Comparison of L2015 with JF or ACRB showed significant changes in predicted function of microbiota in both, IL-M and IL-L. Differences were most prominent between L2015 and JF; while there was no difference between L2015 and L1995.ConclusionsThese data indicate the genetic line × temperature effect on the diversity and composition of IL microbiota. Moreover, the data showcase the effect of host genetics on the composition of IL microbiota and their predicted function. These data are of critical importance for devising nutritional strategies to maintain GIT microbial balance and alleviate the negative effects of HS on broiler chickens’ performance and health.

COMPLEX EFFECT OF LOW-INTENSITY LASER RADIATION AND POTASSIUM CHANNEL PEPTIDE INHIBITOR ON MELANOMA CELL SURVIVAL

Melanoma is characterized by an aggressive development and a large number of metastases during diagnostics. Photodynamic therapy (PDT) is used to treat this type of cancer. However, the accumulation of photosensitizers is observed not only in malignant tumors, but also in high metabolic rate organs. Shortcomings of melanoma therapy can be eliminated using the complex effect of laser radiation and local administration of inhibitors of cellular processes.
 The goal. To study the complex effect of low-intensity laser radiation and potassium channel peptide inhibitor on melanoma cell survival.
 Materials and Methods. A875 melanoma cells were exposed to Kappa-theraphotoxin-Gr1b toxin and laser irradiation. The authors examined the level of apoptosis and necrosis in cells using fluorescence microscopy techniques. The xCELLigence system was used to assess the cytotoxic response of A875 melanoma cells.
 Results. The maximum number of apoptotic and necrotic cells was observed in the group of patients with A875 tumor cells exposed to a combination of Kappa-TRTX-Gr1b toxin and laser radiation (wavelength=1265 nm). This is due to the inhibition of potassium channels of intracellular cell membranes by Kappa-TRTX-Gr1b peptide, which are associated with the apoptosis.
 Conclusion. Selective potassium channel inhibition under pathological processes can be regarded as a significant supplement to the superficial malignant neoplasm complex therapy. The combination of toxin and irradiation will make it possible to potentiate their action and avoid the main PDT disadvantages. This approach unites the benefits of the local administration and precise exposure on the malignant tumor.

Biocompatibility study of tobacco mosaic virus nanoparticles on human alveolar bone cells

One of the most important factors in a dental implant's success is an adequate quantity of supporting bone. However, there are still some limitations for the bone substitution material. Previous studies found that tobacco mosaic virus (TMV) had the potential for bone formation induction. The aim of this study was to evaluate the biocompatibility of TMV with primary human alveolar bone cells. Primary human alveolar bone cells were cultured on TMV coated substrates. Cell viability, alkaline phosphatase activity, calcium matrix mineralization forming ability, immunofluorescence staining for osteocalcin synthesis and cell morphology were assessed. The results showed that primary human alveolar bone cells cultured on the TMV coated substrates had a higher metabolic rate than the non-TMV coated control group at days 1, 3, 7 and 14. Moreover, the calcium deposition was positive and the alkaline phosphatase activity assay was found significantly greater than the control group at day 14 (p < 0.05). The osteocalcin protein synthesis was found in both the TMV coated substrates and the control group. The immunofluorescence study revealed that in the TMV coated substrates group, the cell morphology changed into a polygonal shape and aggregated more quickly than the control group. The present findings conclude that TMV is biocompatible with primary human alveolar bone cells and also shows osteoinduction potential.

Brain size, gut size and cognitive abilities: the energy trade-offs tested in artificial selection experiment.

The enlarged brains of homeotherms bring behavioural advantages, but also incur high energy expenditures. The ‘expensive brain’ (EB) hypothesis posits that the energetic costs of the enlarged brain and the resulting increased cognitive abilities (CA) were met by either increased energy turnover or reduced allocation to other expensive organs, such as the gut. We tested the EB hypothesis by analysing correlated responses to selection in an experimental evolution model system, which comprises line types of laboratory mice selected for high or low basal metabolic rate (BMR), maximum (VO2max) metabolic rates and random-bred (unselected) lines. The traits are implicated in the evolution of homeothermy, having been pre-requisites for the encephalization and exceptional CA of mammals, including humans. High-BMR mice had bigger guts, but not brains, than mice of other line types. Yet, they were superior in the cognitive tasks carried out in both reward and avoidance learning contexts and had higher neuronal plasticity (indexed as the long-term potentiation) than their counterparts. Our data indicate that the evolutionary increase of CA in mammals was initially associated with increased BMR and brain plasticity. It was also fuelled by an enlarged gut, which was not traded off for brain size.