Sex differences in the expression of lipid oxidation and glucose uptake genes in muscles of fasted mice

Fasting has become increasingly popular for treatment and prevention of obesity. Sex differences in the mechanisms of adaptation to fasting may contribute to choosing a therapeutic strategy for correction of metabolic disorders. Hepatokine fibroblast growth factor 21 (FGF21) is involved in the adaptation to fasting. Muscles are assumed to be the main energy-consuming tissue in the body, as muscle metabolism plays an important role in the adaptation to nutritional deficit. However, there is still little information on sex differences in muscle and FGF21 physiological response to fasting. Our aim was to find out whether there were sex differences in hormonal regulation and the expression of genes controlling glucose and lipid metabolism in skeletal muscles in response to fasting. We estimated the effect of 24-hour fasting on the expression of genes involved in lipid (Ucp3, Cpt1) and carbohydrate (Slc2a4) metabolism in muscles and evaluated changes in body weight and blood plasma levels of glucose, insulin, free fatty acids (FFA), adiponectin, and FGF21 in male and female C57BL/6J mice. None of the genes studied (Ucp3, Cpt1 and Slc2a4) showed sex-related changes at mRNA levels in control groups, but females exposed to fasting demonstrated a significant increase in the expression of all genes as compared to control. Fasting significantly decreased body weight and glucose blood plasma levels in animals of both sexes but exerted no effect on the levels of insulin or FFA. The adiponectin and FGF21 levels were increased in response to fasting, the increase in females being significant. We were first to show sex dimorphism in muscle gene expression and FGF21 blood level in response to fasting. In females, the greater increase in FGF21 and adiponectin blood levels was positively associated with the greater upregulation of lipid oxidation and glucose uptake gene expression

Production of reactive oxygen species by neutrophils and macrophages of F1 hybrid mice (C57Bl6xCBA) in response to stimulation with cucurbit(n)urils (n = 6, 7, 8)

Background. Due to their very small size, nanomaterials, in particular cucurbiturils, have unique physical and chemical properties that find their application in medicine. However, the toxicity of cucurbiturils is not fully understood; in particular, we are interested in the immunological safety of their use. One of the mechanisms of nanotoxicity is the formation of reactive oxygen species (ROS) by macrophages and neutrophils. Hyperproduction of ROS can lead to oxidative stress and further damage to cell DNA with loss of physiological function and development of pathology.   The aim. Evaluation of the effect of cucurbit[n]urils (n = 6, 7, 8) on the production of reactive oxygen species by mice macrophages and neutrophils.   Materials and methods. F1 hybrid mice (CBAxC57Bl/6) aged 2 months (n = 11) were used in the work. Evaluation of superoxide radical production by peritoneal mouse neutrophils and macrophages was carried out by spectrophotometric method for determining the reduction of p-nitroblue tetrazolium (NBT) to formazan.   Results. It was shown that CB[6] and CB[7] at concentrations of 0.5 and 0.3 mM do not have an inhibitory effect on ROS synthesis, but, on the contrary, significantly increase ROS production by macrophages. In addition, CB[6] 0.3 mM increases the level of ROS in neutrophils.   Conclusion. Cucurbiturils can lead to an increase in the production of ROS in immunocompetent cells, depending on the concentration used (0.3 mM and higher)

Efficient chimeric mouse production using a novel embryonic stem cell line

Embryonic stem cells are commonly used for generation of transgenic mice. Embryonic stem cells could participate in the development of chimeric animals after injection into a blastocyst. Injection of genetically modified embryonic stem cells could lead to germ line transmission of a transgene or genomic modification in chimeric mice. Such founders are used to produce transgenic lines of mice. There are several projects dedicated to production of knock-out mouse lines (KOMP Repository, EUCOMM, Lexicon Genetics). Never-theless, there is a need for complex genome modifications, such as large deletions, reporter genes insertion into the 3’ gene regulatory sequence, or site-specific modifications of the genome. To do that, researchers need an embryonic stem cell line that is able to participate in chimeric animal formation even after prolonged culture in vitro. Several lines of mouse embryonic stem cells were produced in the Laboratory of Developmental Genetics of the Institute of Cytology and Genetics SB RAS. We tested DGES1 cell line (2n = 40, XY) (129S2/SvPasCrl genetic background) for chimeric mice production at the Center for Genetic Resources of Laboratory Animals at ICG SB RAS. Embryonic stem cells were injected into 136 blastocysts (B6D2F1 genetic background), which were transplanted into CD-1 mice. Among 66 progeny, 15 were chimeric, 4 of which were more than 80 % chimeric judged by coat color. All chimeras were males without developmental abnormalities. 10 of 15 males were fertile. Microsatellite analysis of the progeny of chimeric mice revealed embryonic stem cell line DGES1 contribution to the gamete formation. Thus, a novel DGES1 embryonic stem cell line could be efficiently used for transgenic mouse production using B6D2F1 blastocysts and CD-1 recipients

Morphophysiological alterations caused by insertional mutagenesis of contactin 5 (Cntn5) gene in transgenic mice

Transgenesis has become a routine for modern biological studies. The most popular method for producing transgenic animals–pronuclear microinjection–frequently leads to host gene disruption due to a random transgene integration. In this paper, we report our analysis of morphophysiological parameters of the transgenic mouse line GM9, in which a transgene designed for milk-specific expression of the human granulocyte-macrophage colony-stimulating factor (GM-CSF) gene was integrated into the intron of the Contactin 5 gene (Cntn5). We studied Cntn5 expression with RT-PCR and discovered that its expression in the brain, the primary organ of Cntn5 activity, was unperturbed. However, transgenic animals had less Cntn5 transcripts in other tissues such as the kidney and heart. In addition, we observed a decreased amount of splice variants of Cntn5 exons that flank the transgene integration site. These data suggest that the transgene integration event might affect proper Cntn5 splicing in some tissues. Publications exist that imply that some polymorphisms in the Cntn5 gene are associated with obesity and arterial hypertension in humans. We evaluated core parameters of lipid metabolism and heart activity in mice homozygous and heterozygous for Cntn5 mutation using wild- type animals as control. Our results uncovered that homozygous mutant mice have lower body weight than controls and that it is caused by slower accumulation of fat tissue. Cntn5 mutants also exhibit abnormalities in blood circulation: homozygous Cntn5 mutants are characterized by a higher blood pressure and heart beat rate, as well as faster blood flow in the tail vessels. Heterozygous animals showed intermediate results for all of these parameters

Experimental opisthorchiasis: a study of blood cells, hematopoiesis and startle reflex in laboratory animals

One of the species of the family Opisthorchiidae, Opisthorchis felineus (O. felineus), causes severe disturbances in humans and animals, and so it is the subject of important research studies. Two weeks after infection we compared the impact of O. felineus invasion on the changes in blood cells composition, bone marrow hematopoiesis and behavioral startlereflex in inbred C57BL/6 male mice and Syrian hamsters (Mesocricetus auratus). Considerable interspecies differences were revealed for many parameters estimated. It was found that the relative weight of the main organ of the peripheral immune system – spleen, is significantly larger in mice than in hamsters. Moreover, the infection with O. felineus caused a significant enlargement of the spleen only in mice. More pronounced changes in the blood cells composition, which was accompanied by activation of hematopoietic stem cells of myeloid and erythroid set, were determined in hamsters. Blood changes in the response to infection in mice were less severe and were not accompanied by the changes in colony formation. Mouse acoustic startle reaction differed from hamster one too. The expression of the startle reaction and the value of pre-pulse inhibition were discriminated in animals of two species. Infected hamsters had no reaction of habituation  to the sound stimulus. In addition, the maturation of O. felineus worms was faster in hamsters than in mice. Data obtained suggest a greater resistance of mice to O. felineus infection, but do not exclude the availability of mice as a model in the study of processes taking place in the host during the development of experimental opisthorchiasis

Reproductive effects of the tumor necrosis factor (TNF) deficiency in mice

TNF is a multifunctional cytokine that, at physiological concentrations, maintains the balance between apoptosis and survival of male germ cells and, at higher concentrations, has adverse effects on various stages of the reproductive process. Although ant-cytokine therapies have been used in millions of patients, the consequences of cytokine deficiency for reproductive functions are poorly understood and need attention. In this work, we have studied behavioral interactions between males and females, spermatogenesis, male fertility, and embryonic developmental characteristics of the progeny in TNFα knockout mice (TNF-/-). We have demonstrated that TNF is involved in the regulation of sexual behavior, spermatogenesis, pre- and postimplantation development. Complete TNF deficiency led to decreased reproductive efficiency: a lower number of viable embryos were observed in TNF-/- mice than in wild-type mice. The decrease in fertility was caused by preimplantation embryo loss in TNF-/- mice. Preimplantation loss in females might be caused by asospermia in TNF-/- males. Additionally, the sensitivity of reproductive functions to female stimuli was different between TNF-/- mice and wild-type mice, while interactions with females increased the concentrations of sper­matozoids in both TNF-/- and wild-type mice. Still higher levels were observed in knockout animals, which led to increase in the number of immature spermatozoids in epididymides

Whole-Genome Sequencing analysis of Human Metabolome in Multi-Ethnic Populations

Circulating metabolite levels may reflect the state of the human organism in health and disease, however, the genetic architecture of metabolites is not fully understood. We have performed a whole-genome sequencing association analysis of both common and rare variants in up to 11,840 multi-ethnic participants from five studies with up to 1666 circulating metabolites. We have discovered 1985 novel variant-metabolite associations, and validated 761 locus-metabolite associations reported previously. Seventy-nine novel variant-metabolite associations have been replicated, including three genetic loci located on the X chromosome that have demonstrated its involvement in metabolic regulation. Gene-based analysis have provided further support for seven metabolite-replicated loci pairs and their biologically plausible genes. Among those novel replicated variant-metabolite pairs, follow-up analyses have revealed that 26 metabolites have colocalized with 21 tissues, seven metabolite-disease outcome associations have been putatively causal, and 7 metabolites might be regulated by plasma protein levels. Our results have depicted the genetic contribution to circulating metabolite levels, providing additional insights into understanding human disease

Publisher Correction:Discovery of rare variants associated with blood pressure regulation through meta-analysis of 1.3 million individuals (Nature Genetics, (2020), 52, 12, (1314-1332), 10.1038/s41588-020-00713-x)

In the version of this article originally published, the e-mail address of corresponding author Patricia B. Munroe was incorrect. The error has been corrected in the HTML and PDF versions of the article

Discovery of rare variants associated with blood pressure regulation through meta-analysis of 1.3 million individuals

Correction: Volume53, Issue5 Page 762-762 DOI: 10.1038/s41588-021-00832-z Published MAY 2021Genetic studies of blood pressure (BP) to date have mainly analyzed common variants (minor allele frequency > 0.05). In a meta-analysis of up to similar to 1.3 million participants, we discovered 106 new BP-associated genomic regions and 87 rare (minor allele frequencyPeer reviewe

Evaluating the use of blood pressure polygenic risk scores across race/ethnic background groups.

We assess performance and limitations of polygenic risk scores (PRSs) for multiple blood pressure (BP) phenotypes in diverse population groups. We compare "clumping-and-thresholding" (PRSice2) and LD-based (LDPred2) methods to construct PRSs from each of multiple GWAS, as well as multi-PRS approaches that sum PRSs with and without weights, including PRS-CSx. We use datasets from the MGB Biobank, TOPMed study, UK biobank, and from All of Us to train, assess, and validate PRSs in groups defined by self-reported race/ethnic background (Asian, Black, Hispanic/Latino, and White). For both SBP and DBP, the PRS-CSx based PRS, constructed as a weighted sum of PRSs developed from multiple independent GWAS, perform best across all race/ethnic backgrounds. Stratified analysis in All of Us shows that PRSs are better predictive of BP in females compared to males, individuals without obesity, and middle-aged (40-60 years) compared to older and younger individuals