Search

Abstract Obesity adversely affects bone and fat metabolism in mice and humans. Omega-3 polyunsaturated fatty acids (omega-3 PUFAs) have been shown to improve glucose metabolism and bone homeostasis in obesity. However, the impact of omega-3 PUFAs on bone marrow adipose tissue (BMAT) and bone marrow stromal cell (BMSC) metabolism has not been intensively studied yet. In the present study we demonstrated that omega-3 PUFA supplementation in high fat diet (HFD + F) improved bone parameters, mechanical properties along with decreased BMAT in obese mice when compared to the HFD group. Primary BMSCs isolated from HFD + F mice showed decreased adipocyte and higher osteoblast differentiation with lower senescent phenotype along with decreased osteoclast formation suggesting improved bone marrow microenvironment promoting bone formation in mice. Thus, our study highlights the beneficial effects of omega-3 PUFA-enriched diet on bone and cellular metabolism and its potential use in the treatment of metabolic bone diseases.

Objective: The use of thiazolidinediones (TZDs) as insulin sensitizers has been shown to have side effects including increased accumulation of bone marrow adipocytes (BMAds) associated with a higher fracture risk and bone loss. A novel TZD analog MSDC-0602K with low affinity to PPARγ has been developed to reduce adverse effects of TZD therapy. However, the effect of MSDC-0602K on bone phenotype and bone marrow mesenchymal stem cells (BM-MSCs) in relation to obesity has not been intensively studied yet. Methods: Here, we investigated whether 8-week treatment with MSDC-0602K has a less detrimental effect on bone loss and BM-MSC properties in obese mice in comparison to first generation of TZDs, pioglitazone. Bone parameters (bone microstructure, bone marrow adiposity, bone strength) were examined by μCT and 3-point bending test. Primary BM-MSCs were isolated and measured for osteoblast and adipocyte differentiation. Cellular senescence, bioenergetic profiling, nutrient consumption and insulin signaling were also determined. Results: The findings demonstrate that MSDC-0602K improved bone parameters along with increased proportion of smaller BMAds in tibia of obese mice when compared to pioglitazone. Further, primary BM-MSCs isolated from treated mice and human BM-MSCs revealed decreased adipocyte and higher osteoblast differentiation accompanied with less inflammatory and senescent phenotype induced by MSDC-0602K vs. pioglitazone. These changes were further reflected by increased glycolytic activity differently affecting glutamine and glucose cellular metabolism in MSDC-0602K-treated cells compared to pioglitazone, associated with higher osteogenesis. Conclusion: Our study provides novel insights into the action of MSDC-0602K in obese mice, characterized by the absence of detrimental effects on bone quality and BM-MSC metabolism when compared to classical TZDs and thus suggesting a potential therapeutical use of MSDC-0602K in both metabolic and bone diseases.

Turnip yellows virus (TuYV), is one of the most important pathogens of oilseed rape, which has caused enormous yield losses in all growing regions of the world in recent years. Therefore, there is a need for resistant varieties for sustainable crop protection. We have investigated the resistance of known varieties and newly developed advanced-breeding lines of oilseed rape to TuYV in greenhouse and field trials. We have analysed the TuYV titre of individual genotypes inoculated with the virus using viruliferous aphids Myzus persicae. The genotypes ‘DK Temptation’ and ‘Rescator’ had the lowest and highest virus titres, respectively, and were used as resistant and susceptible models for comparative analyses with other genotypes. In the greenhouse, the best results were obtained with the genotypes ‘OP-8143 DH’ (2.94 × 105 copies), OP-BN-72 (3.29 × 105 copies), ‘Navajo’ (3.58 × 105 copies) and ‘SG-C 21215’ (4.09 × 105 copies), which reached virus titres about 2 times higher than the minimum virus concentration measured in ‘DK Temptation’ (1.80 × 105 copies). In the field trials, the genotypes ‘Navajo’ (3.39 × 105 copies), ‘OP-8148 DH’ (4.44 × 105 copies), ‘SG-C 21215’ (6.80 × 105 copies) and OP-8480 (7.19 × 105 copies) had the lowest virus titres and reached about 3 times the virus titre of DK Temptation (2.54 × 105 copies). Both trials showed that at least two commercial varieties (e.g., DK Temptation, Navajo) and three advanced breeding lines (e.g., OP-8143 DH, OP-BN-72, SG-C 21215) had low titres of the virus after TuYV infection. This indicates a high level of resistance to TuYV in ‘Navajo’ or the newly developed breeding lines and the basis of resistance is probably different from R54 (as in ‘DK Temptation’). Furthermore, the greenhouse trials together with RT -qPCR-based virus titre analysis could be a cost-effective and efficient method to assess the level of resistance of a given genotype to TuYV infection compared to the field trials. However, further research is needed to identify the underlying mechanisms causing this difference in susceptibility.

Wheat dwarf virus (WDV) is one of the most important pathogens of cereal crops worldwide. To understand the molecular mechanism of resistance, here we investigated the comparative transcriptome of wheat genotypes with different levels of resistance (Svitava and Fengyou 3) and susceptibility (Akteur) to WDV. We found a significantly higher number of differentially expressed transcripts (DETs) in the susceptible genotype than in the resistant one (e.g., Svitava). The number of downregulated transcripts was also higher in the susceptible genotype than in the resistant one (Svitava) and the opposite was true for the upregulated transcripts. Further functional analysis of gene ontology (GO) enrichment identified a total of 114 GO terms for the DETs. Of these, 64 biological processes, 28 cellular components and 22 molecular function GO terms were significantly enriched. A few of these genes appear to have a specific expression pattern related to resistance or susceptibility to WDV infection. Validation of the expression pattern by RT-qPCR showed that glycosyltransferase was significantly downregulated in the susceptible genotype compared to the resistant genotypes after WDV infection, while CYCLIN-T1-3, a regulator of CDK kinases (cyclin-dependent kinase), was upregulated. On the other hand, the expression pattern of the transcription factor (TF) MYB (TraesCS4B02G174600.2; myeloblastosis domain of transcription factor) was downregulated by WDV infection in the resistant genotypes compared to the susceptible genotype, while a large number of TFs belonging to 54 TF families were differentially expressed due to WDV infection. In addition, two transcripts (TraesCS7A02G341400.1 and TraesCS3B02G239900.1) were upregulated with uncharacterised proteins involved in transport and regulation of cell growth, respectively. Altogether, our findings showed a clear gene expression profile associated with resistance or susceptibility of wheat to WDV. In future studies, we will explore the regulatory network within the same experiment context. This knowledge will broaden not only the future for the development of virus-resistant wheat genotypes but also the future of genetic improvement of cereals for resilience and WDV-resistance breeding.

Barley yellow dwarf viruses (BYDVs) are one of the most widespread and economically important plant viruses affecting many cereal crops. Growing resistant varieties remains the most promising approach to reduce the impact of BYDVs. A Recent RNA sequencing analysis has revealed potential genes that respond to BYDV infection in resistant barley genotypes. Together with a comprehensive review of the current knowledge on disease resistance in plants, we selected nine putative barley and wheat genes to investigate their involvement in resistance to BYDV-PAV infection. The target classes of genes were (i) nucleotide binding site (NBS) leucine-rich repeat (LRR), (ii) coiled-coil nucleotide-binding leucine-rich repeat (CC-NB-LRR), (iii) LRR receptor-like kinase (RLK), (iv) casein kinase, (v) protein kinase, (vi) protein phosphatase subunits and the transcription factors (TF) (vii) MYB TF, (viii) GRAS (gibberellic acid-insensitive (GAI), repressor of GAI (RGA) and scarecrow (SCR)), and (ix) the MADS-box TF family. Expression of genes was analysed for six genotypes with different levels of resistance. As in previous reports, the highest BYDV-PAV titre was found in the susceptible genotypes Graciosa in barley and Semper and SGS 27-02 in wheat, which contrast with the resistant genotypes PRS-3628 and Wysor of wheat and barley, respectively. Statistically significant changes in wheat show up-regulation of NBS-LRR, CC-NBS-LRR and RLK in the susceptible genotypes and down-regulation in the resistant genotypes in response to BYDV-PAV. Similar up-regulation of NBS-LRR, CC-NBS-LRR, RLK and MYB TF in response to BYDV-PAV was also observed in the susceptible barley genotypes. However, no significant changes in the expression of these genes were generally observed in the resistant barley genotypes, except for the down-regulation of RLK. Casein kinase and Protein phosphatase were up-regulated early, 10 days after inoculation (dai) in the susceptible wheat genotypes, while the latter was down-regulated at 30 dai in resistant genotypes. Protein kinase was down-regulated both earlier (10 dai) and later (30 dai) in the susceptible wheat genotypes, but only in the later dai in the resistant genotypes. In contrast, GRAS TF and MYB TF were up-regulated in the susceptible wheat genotypes while no significant differences in MADS TF expression was observed. Protein kinase, Casein kinase (30 dai), MYB TF and GRAS TF (10 dai) were all up-regulated in the susceptible barley genotypes. However, no significant differences were found between the resistant and susceptible barley genotypes for the Protein phosphatase and MADS FT genes. Overall, our results showed a clear differentiation of gene expression patterns in both resistant and susceptible genotypes of wheat and barley. Therefore, further research on RLK, NBS-LRR, CC-NBS-LRR, GRAS TF and MYB TF can lead to BYDV-PAV resistance in cereals.

Turnip yellows virus (TuYV) is one of the most important pathogens of oilseed rape worldwide. The virus has a large host range including many crop species (e.g., oilseed rape, pea, chickpea) and weeds from more than twenty plant families. Other than oilseed rape, we detected TuYV in many commonly grown weed species that share the fields and vegetation period together with canola crops in Czech and Slovak Republics. TuYV was detected by reverse-transcription polymerase chain reaction (RT-PCR) in at least 26 species including main crop hosts (oilseed rape), intercrops and weeds such as Amaranthus retroflexus, Atriplex patula (Amaranthaceae), Arctium lappa, Lactuca serriola, Taraxacum officinale, Tripleurospermum inodorum (Asteraceae), Phacelia tanacetifolia (Boraginaceae), Brassica napus, Capsella bursa–pastoris, Descurainia Sophia, Raphanus raphanistrum, Sinapis alba, Sisymbrium officinale, Thlaspi arvense (Brassicaceae), Silene alba, Stellaria media (Caryophyllaceae), Euphorbia helioscopia (Euphorbiaceae), Geranium rotundifolium (Geraniaceae), Lamium purpureum (Lamiaceae), Fumaria officinalis, Papaver rhoeas (Papaveraceae), Veronica persica (Plantaginaceae syn. Scrophulariaceae), Fallopia convolvulus (Polygonaceae), Solanum nigrum (Solanaceae), Urtica dioica (Urticaceae) and Viola arvensis (Violaceae). The detection of TuYV was further confirmed by RT-qPCR as well as Sanger sequencing of the PCR fragments. We discovered four new weed species as hosts of TuYV such as T. inodorum, S. alba, G. rotundifolium and E. helioscopia, representing their three respective plant families. The readthrough domain (RTD) gene sequence analysis of the Czech and Slovak TuYV isolates from oilseed rape and weed species showed similar within-group nucleotide divergence (7.1% and 5.6%, respectively) and the absence of geographical- or host-based phylogenetic clustering. The high-throughput sequencing of the P. rhoeas sample enabled the obtention of a nearly complete genome of TuYV and revealed the mixed infection of TuYV with turnip mosaic virus and cucumber mosaic virus. Our results thus show that weed species are an important TuYV reservoir and play a significant role in the spread and incidence of the disease in field crops such as oilseed rape.

In the present study the hypothesis that there is a feedback between juvenile hormone and adipokinetic hormones (AKHs) was investigated by topical application of the juvenoid methoprene on 9-day-old adult males of the firebug Pyrrhocoris apterus. This juvenoid (2 µg) induced a significant reduction of haemolymph lipids 24 h after treatment; however, it did not significantly reduce the ability of Pyrap-AKH (10 pmol/bug) to mobilize fat body lipids 6-72 h after the methoprene application. The same methoprene treatment elicited a significant increase of AKH content in the CNS (central nervous system: brain + corpora cardiaca + corpora allata) of experimental males 24 and 48 h after the juvenoid application. A significant decrease in the AKH level in the haemolymph was recorded at the same times and under the same experimental conditions. Similar results were observed when production of the AKHs from the CNS of topically treated males was measured under in vitro conditions. It is suggested that methoprene may reduce AKH release from the CNS resulting in an increase in the AKH content of the CNS due to accumulation rather than stimulation of AKH synthesis. Possible consequences of this phenomenon on the physiology of P. apterus are discussed.

Preptin, a 34-amino acid peptide derived from pro-IGF2, is believed to influence various physiological processes, including insulin secretion and the regulation of bone metabolism. Despite its recognized involvement, the precise physiological role of preptin remains enigmatic. To address this knowledge gap, we synthesized 16 analogs of preptin, spanning a spectrum from full-length forms to fragments, and conducted comprehensive comparative activity evaluations alongside native human, mouse and rat preptin. Our study aimed to elucidate the physiological role of preptin. Contrary to previous indications of broad biological activity, our thorough analyses across diverse cell types revealed no significant biological activity associated with preptin or its analogs. This suggests that the associations of preptin with various diseases or tissue-specific abundance fluctuations may be influenced by factors beyond preptin itself, such as higher levels of IGF2 or IGF2 proforms present in tissues. In conclusion, our findings challenge the conventional notion of preptin as an isolated biologically active molecule and underscore the complexity of its interactions within biological systems. Rather than acting independently, the observed effects of preptin may arise from experimental conditions, elevated preptin concentrations, or interactions with related molecules such as IGF2. [ABSTRACT FROM AUTHOR]