Browsing by Subject "gene expression"

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  • Untiveros, Milton; Olspert, Allan; Artola, Katrin; Firth, Andrew E.; Kreuze, Jan F.; Valkonen, Jari P. T. (2016)
    The single-stranded, positive-sense RNA genome of viruses in the genus Potyvirus encodes a large polyprotein that is cleaved to yield 10 mature proteins. The first three cleavage products are P1, HCpro and P3. An additional short open reading frame (ORF), called pipo, overlaps the P3 region of the polyprotein ORF. Four related potyviruses infecting sweet potato (Ipomoea batatas) are predicted to contain a third ORF, called pispo, which overlaps the 3 third of the P1 region. Recently, pipo has been shown to be expressed via polymerase slippage at a conserved GA(6) sequence. Here, we show that pispo is also expressed via polymerase slippage at a GA(6) sequence, with higher slippage efficiency (approximate to 5%) than at the pipo site (approximate to 1%). Transient expression of recombinant P1 or the transframe' product, P1N-PISPO, in Nicotiana benthamiana suppressed local RNA silencing (RNAi), but only P1N-PISPO inhibited short-distance movement of the silencing signal. These results reveal that polymerase slippage in potyviruses is not limited to pipo expression, but can be co-opted for the evolution and expression of further novel gene products.
  • Einarsdottir, Elisabet; Pekkinen, Minna; Krjutskov, Kaarel; Katayama, Shintaro; Kere, Juha; Mäkitie, Outi; Viljakainen, Heli (2019)
    Objective: The effect of vitamin D at the transcriptome level is poorly understood, and furthermore, it is unclear if it differs between obese and normal-weight subjects. The objective of the study was to explore the transcriptome effects of vitamin D supplementation. Design and methods: We analysed peripheral blood gene expression using GlobinLock oligonucleotides followed by RNA sequencing in individuals participating in a 12-week randomised double-blinded placebo-controlled vitamin D intervention study. The study involved 18 obese and 18 normal-weight subjects (of which 20 males) with mean (+/- s.D.) age 20.4 (+/- 2.5) years and BMIs 36 (+/- 10) and 23 (+/- 4) kg/m(2), respectively. The supplemental daily vitamin D dose was 50 mu g (2000 IU). Data were available at baseline, 6- and 12-week time points and comparisons were performed between the vitamin D and placebo groups separately in obese and normal-weight subjects. Results: Significant transcriptomic changes were observed at 6 weeks, and only in the obese subjects: 1724 genes were significantly upregulated and 186 genes were downregulated in the vitamin D group compared with placebo. Further analyses showed several enriched gene categories connected to mitochondrial function and metabolism, and the most significantly enriched pathway was related to oxidative phosphorylation (adjusted P value 3.08 x 10(-14)). Taken together, our data suggest an effect of vitamin D supplementation on mitochondrial function in obese subjects. Conclusions: Vitamin D supplementation affects gene expression in obese, but not in normal-weight subjects. The altered genes are enriched in pathways related to mitochondrial function. The present study increases the understanding of the effects of vitamin D at the transcriptome level.
  • Sundqvist, Benjamin; Kilpinen, Sami; Böhling, Tom; Koljonen, Virve; Sihto, Harri (2022)
    Background: Merkel cell carcinoma (MCC) is a rare but highly aggressive neuroendocrine carcinoma of the skin with a poor prognosis. Improving the prognosis of MCC by means of targeted therapies requires further understanding of the mechanisms that drive tumor progression. In this study, we aimed to identify the genes, processes, and pathways that play the most crucial roles in determining MCC outcomes. Methods: We investigated transcriptomes generated by RNA sequencing of formalin-fixed paraffin-embedded tissue samples of 102 MCC patients and identified the genes that were upregulated among survivors and in patients who died from MCC. We subsequently cross-referenced these genes with online databases to investigate the functions and pathways they represent. We further investigated differential gene expression based on viral status in patients who died from MCC. Results: We found several novel genes associated with MCC-specific survival. Genes upregulated in patients who died from MCC were most notably associated with angiogenesis and the PI3K-Akt and MAPK pathways; their expression predominantly had no association with viral status in patients who died from MCC. Genes upregulated among survivors were largely associated with antigen presentation and immune response. Conclusion: This outcome-based discrepancy in gene expression suggests that these pathways and processes likely play crucial roles in determining MCC outcomes.
  • Jäppinen, Sanni (Helsingfors universitet, 2013)
    Filamentous cyanobacteria taxa Nostocales and Stigonematales cells can differentiate into heterocysts nitrogen fixing cells when nitrogen is limiting the growth and into resting cells akinetes when nutrients decrease or the growth conditions become unfavorable for growth. Akinetes overwinter in the water sediments during the unfavorable growth time. When the growing condition improves akinetes germinate and can start a new cyanobacterial bloom. Akinete differentiation remains unclear. It is known from the literature that only a few akinete specific genes exist. First described akinete specific gene was avak. The morphological changes of akinete differentiation are known but the changes at molecular genetics level in regulation and differentiation remains unclear. The aim of this study was to design a method for akinete differentiation-related genes, avak, hepA and hap, for an Anabaena 1TU33s10 strain and to monitor the gene expression changes in a seven-week growth experiment. Primers for the differentiation related genes were designed based on the known whole genome sequence of the Anabaena 1TU3310 strain. In this study it was managed to design a quantitative reverse transcriptase polymerase chain reaction, qRT-PCR method, based on the genes involved in the akinete differentiation process. It was observed that gene expression changed when akinetes began to differentiate into the filaments. In the growth experiment II avaK-gene expression was increased 2-fold between the 14. and 30. days, and hap-gene showed 1.5 fold growth between 14. and 30. days. The number of akinetes was also increasing at the same time. In the growth experiment I heap-gene showed 1-8 fold growth between the days 21. and 27. –30. days when the number of heterocysts were also increasing. The number of akinetes was relatively low compared to number of vegetative cells which also explains the small expression fold-differences in the cultures during the experiment time when compared to expression fold-differences described in the literature. Designed method can thus also detect minor changes in gene expression. The designed and built qRT-PCR method can be used in the future for monitoring gene expression changes also for new akinete specific genes, and the method can be further optimized for screening natural water samples.
  • Holster, Savanne; Hooiveld, Guido J.; Repsilber, Dirk; de Vos, Willem M.; Brummer, Robert J.; König, Julia (2019)
    Faecal microbiota transfer (FMT) consists of the introduction of new microbial communities into the intestine of a patient, with the aim of restoring a disturbed gut microbiota. Even though it is used as a potential treatment for various diseases, it is unknown how the host mucosa responds to FMT. This study aims to investigate the colonic mucosa gene expression response to allogenic (from a donor) or autologous (own) FMT in patients with irritable bowel syndrome (IBS). In a recently conducted randomised, double-blinded, controlled clinical study, 17 IBS patients were treated with FMT by colonoscopy. RNA was isolated from colonic biopsies collected by sigmoidoscopy at baseline, as well as two weeks and eight weeks after FMT. In patients treated with allogenic FMT, predominantly immune response-related gene sets were induced, with the strongest response two weeks after the FMT. In patients treated with autologous FMT, predominantly metabolism-related gene sets were affected. Furthermore, several microbiota genera showed correlations with immune-related gene sets, with different correlations found after allogenic compared to autologous FMT. This study shows that the microbe-host response is influenced by FMT on the mucosal gene expression level, and that there are clear differences in response to allogenic compared to autologous FMT.
  • Miettinen, Juho; Kumari, Romika; Traustadottir, Gunnhildur Asta; Huppunen, Maiju-Emilia Anniina; Sergeev, Philipp; Majumder, Muntasir M.; Schepsky, Alexander; Gudjonsson, Thorarinn; Lievonen, Juha; Bazou, Despina; Dowling, Paul; O'Gorman, Peter; Slipicevic, Ana; Anttila, Pekka; Silvennoinen, Raija; Nupponen, Nina N.; Lehmann, Fredrik; Heckman, Caroline (2021)
    Multiple myeloma (MM) is characterized by extensive immunoglobulin production leading to an excessive load on protein homeostasis in tumor cells. Aminopeptidases contribute to proteolysis by catalyzing the hydrolysis of amino acids from proteins or peptides and function downstream of the ubiquitin–proteasome pathway. Notably, aminopeptidases can be utilized in the delivery of antibody and peptide-conjugated drugs, such as melflufen, currently in clinical trials. We analyzed the expression of 39 aminopeptidase genes in MM samples from 122 patients treated at Finnish cancer centers and 892 patients from the CoMMpass database. Based on ranked abundance, LAP3, ERAP2, METAP2, TTP2, and DPP7 were highly expressed in MM. ERAP2, XPNPEP1, DPP3, RNPEP, and CTSV were differentially expressed between relapsed/refractory and newly diagnosed MM samples (p < 0.05). Sensitivity to melflufen was detected ex vivo in 11/15 MM patient samples, and high sensitivity was observed, especially in relapsed/refractory samples. Survival analysis revealed that high expression of XPNPEP1, RNPEP, DPP3, and BLMH (p < 0.05) was associated with shorter overall survival. Hydrolysis analysis demonstrated that melflufen is a substrate for aminopeptidases LAP3, LTA4H, RNPEP, and ANPEP. The sensitivity of MM cell lines to melflufen was reduced by aminopeptidase inhibitors. These results indicate critical roles of aminopeptidases in disease progression and the activity of melflufen in MM.
  • Salmela, Heli; Stark, Taina; Stucki, Dimitri; Fuchs, Siiri; Freitak, Dalial; Dey, Alivia; Kent, Clement F.; Zayed, Amro; Dhaygude, Kishor; Hokkanen, Heikki; Sundstrom, Liselotte (2016)
    Protection against inflammation and oxidative stress is key in slowing down aging processes. The honey bee (Apis mellifera) shows flexible aging patterns linked to the social role of individual bees. One molecular factor associated with honey bee aging regulation is vitellogenin, a lipoglycophosphoprotein with anti-inflammatory and antioxidant properties. Recently, we identified three genes in Hymenopteran genomes arisen from ancient insect vitellogenin duplications, named vg-like-A, -B, and -C. The function of these vitellogenin homologs is unclear. We hypothesize that some of them might share gene-and protein-level similarities and a longevity-supporting role with vitellogenin. Here, we show how the structure and modifications of the vg-like genes and proteins have diverged from vitellogenin. Furthermore, all three vg-like genes show signs of positive selection, but the spatial location of the selected protein sites differ from those found in vitellogenin. We show that all these genes are expressed in both long-lived winter worker bees and in summer nurse bees with intermediate life expectancy, yet only vg-like-A shows elevated expression in winter bees as found in vitellogenin. Finally, we show that vg-like-A responds more strongly than vitellogenin to inflammatory and oxidative conditions in summer nurse bees, and that also vg-like-B responds to oxidative stress. We associate vg-like-A and, to lesser extent, vg-like-B to the antiaging roles of vitellogenin, but that vg-like-C probably is involved in some other function. Our analysis indicates that an ancient duplication event facilitated the adaptive and functional divergence of vitellogenin and its paralogs in the honey bee.
  • Jia, S.; Zhou, J.; Wee, Y.; Mikkola, M. L.; Schneider, P.; D'Souza, R. N. (2017)
    To date, surgical interventions are the only means by which craniofacial anomalies can be corrected so that function, esthetics, and the sense of well-being are restored in affected individuals. Unfortunately, for patients with cleft palate-one of the most common of congenital birth defects-treatment following surgery is prolonged over a lifetime and often involves multidisciplinary regimens. Hence, there is a need to understand the molecular pathways that control palatogenesis and to translate such information for the development of noninvasive therapies that can either prevent or correct cleft palates in humans. Here, we use the well-characterized model of the Pax9(-/-) mouse, which displays a consistent phenotype of a secondary cleft palate, to test a novel therapeutic. Specifically, we demonstrate that the controlled intravenous delivery of a novel mouse monoclonal antibody replacement therapy, which acts as an agonist for the ectodysplasin (Eda) pathway, can resolve cleft palate defects in Pax9(-/-) embryos in utero. Such pharmacological interventions did not reverse the arrest in tooth, thymus, and parathyroid gland development, suggesting that the relationship of Pax9 to the Eda/Edar pathway is both unique and essential for palatogenesis. Expression analyses and unbiased gene expression profiling studies offer a molecular explanation for the resolution of palatal defects, showing that Eda and Edar-related genes are expressed in normal palatal tissues and that the Eda/Edar signaling pathway is downstream of Pax9 in palatogenesis. Taken together, our data uncover a unique relationship between Pax9 and the Eda/Edar signaling pathway that can be further exploited for the development of noninvasive, safe, and effective therapies for the treatment of cleft palate conditions and other single-gene disorders affecting the craniofacial complex.
  • Nykänen, Sonja (Helsingin yliopisto, 2019)
    Colorectal cancer (CRC) kills more than half a million people a year worldwide. Usually the disease develops over several years via multiple steps which involve both genetic and epigenetic alterations. CRC is often diagnosed at late stage, when the cancer has already metastasized, and the prognosis is relatively poor. Several studies suggest that the first changes towards colorectal cancer occur and can be detected in histologically normal tissue before the appearance of any detectable lesion. The precancerous cells harbouring those changes may form a field of tissue, which is predisposed to malignant transformation. The study of pre-cancerous tissue might reveal the earliest changes in CRC development, which can be used as biomarkers for early detection and prevention of CRC. The aim of this thesis was to revise and investigate whether the aberrant expression of the six chromosomal segregation genes, Bub1, Mis18a, Pms2, Rad9a, Tpx2, and Mlh1, would signal carcinogenesis in mouse colon mucosa. Altogether fourteen mice, of which six had a proximal colon carcinoma, were selected for the study. The expression analysis was performed to histologically normal colon mucosa collected from the proximal and distal colon of each mice in order to investigate whether the possible pre-cancerous changes are found exclusively in the close proximity to the carcinoma. The expression was quantified with reverse transcription quantitative polymerase chain reaction (RTqPCR). No statistically significant gene expression differences were found between the carcinoma and control mice, indicating that the studied mice did not display cancer-preceding expression changes of the six studied genes in the carcinoma adjacent histologically normal colon mucosa. The results differed from the previously reported results, where the expressions of the six genes were found to be downregulated in the carcinoma adjacent mucosa. Here, the sample size was presumably not large enough to reveal statistically significant clustering of the expression patterns. However, Bub1 seemed to have a downregulated trend in the carcinoma adjacent mucosa, which supports the previously suggested role of Bub1 alterations in CRC initiation.
  • Piran, Mehran; Karbalaei, Reza; Piran, Mehrdad; Aldahdooh, Jehad; Mirzaie, Mehdi; Ansari-Pour, Naser; Tang, Jing; Jafari, Mohieddin (2020)
    Studying relationships among gene products by expression profile analysis is a common approach in systems biology. Many studies have generalized the outcomes to the different levels of central dogma information flow and assumed a correlation of transcript and protein expression levels. However, the relation between the various types of interaction (i.e., activation and inhibition) of gene products to their expression profiles has not been widely studied. In fact, looking for any perturbation according to differentially expressed genes is the common approach, while analyzing the effects of altered expression on the activity of signaling pathways is often ignored. In this study, we examine whether significant changes in gene expression necessarily lead to dysregulated signaling pathways. Using four commonly used and comprehensive databases, we extracted all relevant gene expression data and all relationships among directly linked gene pairs. We aimed to evaluate the ratio of coherency or sign consistency between the expression level as well as the causal relationships among the gene pairs. Through a comparison with random unconnected gene pairs, we illustrate that the signaling network is incoherent, and inconsistent with the recorded expression profile. Finally, we demonstrate that, to infer perturbed signaling pathways, we need to consider the type of relationships in addition to gene-product expression data, especially at the transcript level. We assert that identifying enriched biological processes via differentially expressed genes is limited when attempting to infer dysregulated pathways.
  • Pirttikoski, Anna (Helsingin yliopisto, 2022)
    Ovarian cancer is the most lethal gynecological cancer and high-grade serous ovarian cancer (HGSOC) is the most common type of it. HGSOC is often diagnosed in advanced stages and most patients will relapse after optimal first-line treatment. One reason for the lack of successful treatment in HGSOC is high tumor heterogeneity including differences across the tumors in distinct patients, and even within each tumor. This heterogeneity is the result of genetic and non genetic factors. Phenotypical variabilty exists also within cancer cells that have the same genetic background. This is due to the fact that a cell can exist in more than one stable state where its genome is in a specific configuration and it expresses certain genes. Diverse cell states and transitions between them initially offer a path for tumor development, and later enable essential tumor behavior, such as metastasis and survival in variable environmental pressures, such as those posed by anti-cancer therapies. Generally, phenotypic heterogeneity is acquired from the cell of origin for a tumor. This thesis studies cell states in HGSOC cancer cells and their normal counterparts, fallopian tube epithelial cells. Exploration of cell states is based on gene expression data of individual cells. Gene expression data was analyzed with state-of-the-art tools and computational methods. Gene modules representing cell states were constructed using genes found in differential gene expression analysis of cancer cells, normal cells and tumor microenvironment. Differentially expressed gene (DEG) groups of cancer, normal FTE and shared epithelial genes were grouped separately into gene modules based on gene-gene associations and community detection. Potential dynamical relationships between cell states were addressed by pseudo-temporal ordering using RNA velocity modeling approach. We are able to capture biologically meaningful cell states which are relevant in the development of HGSOC with chosen research strategy. Found cell states represent processes such as epithelial-mesenchymal transition, inflammation and stress response which are known to have a role in cancer development. The transition patterns showed consistent tendencies across the samples, and the trajectories for normal samples presented more directionality than those of cancer specimens. The results indicate existence of shared epithelial states which stay in fixed positions in the developmental trajectory of normal and cancer cells. For example, both epithelial stem cells and stem-like cancer cells seem to utilize oxidative phosphorylation (OXPHOS) for their metabolic needs. On the other hand, cell states that are more terminal showed higher activities of tumor necrosis factor alpha and Wnt/beta-catenin pathways that were both mutually exclusive with OXPHOS. Overall, this thesis presents a novel approach to study cell states the characterization of which is essential in understanding tumorigenesis and cancer cell plasticity.
  • Kianersi, Farzad; Amin Azarm, Davood; Pour-Aboughadareh, Alireza; Poczai, Peter (2022)
    The medicinal herb, lemon balm (Melissa officinalis L.), which is high in rosmarinic acid (RA), has well-known therapeutic value. The goals of this study were to investigate the effects of methyl jasmonate (MeJA) on RA content, total phenolic content (TPC), and total flavonoid content (TFC), as well as changes in expression of their biosynthesis-related key genes (MoPAL, Mo4CL, and MoRAS) in Iranian lemon balm ecotypes, as first reported. Our results revealed that MeJA doses significantly increase the RA content, TPC, and TFC in both ecotypes compared with the control samples. Additionally, the higher expression levels of MoPAL, Mo4CL, and MoRAS following treatment were linked to RA accumulation in all treatments for both Iranian lemon balm ecotypes. After 24 h of exposure to 150 mu M MeJA concentration, HPLC analysis showed that MeJA significantly increased RA content in Esfahan and Ilam ecotypes, which was about 4.18- and 7.43-fold higher than untreated plants. Our findings suggested that MeJA has a considerable influence on RA, TPC, and TFC accumulation in MeJA-treated Iranian M. officinalis, which might be the result of gene activation from the phenylpropanoid pathway. As a result of our findings, we now have a better understanding of the molecular processes behind RA production in lemon balm plants.
  • Jalanka, Jonna; Cheng, Jing; Hiippala, Kaisa; Ritari, Jarmo; Salojärvi, Jarkko; Ruuska, Tarja; Kalliomaki, Marko; Satokari, Reetta (2020)
    Inflammatory bowel diseases (IBD), ulcerative colitis (UC) and Crohn's disease (CD), are chronic debilitating disorders of unknown etiology. Over 200 genetic risk loci are associated with IBD, highlighting a key role for immunological and epithelial barrier functions. Environmental factors account for the growing incidence of IBD, and microbiota are considered as an important contributor. Microbiota dysbiosis can lead to a loss of tolerogenic immune effects and initiate or exacerbate inflammation. We aimed to study colonic mucosal microbiota and the expression of selected host genes in pediatric UC. We used high-throughput 16S rDNA sequencing to profile microbiota in colonic biopsies of pediatric UC patients (n= 26) and non-IBD controls (n= 27). The expression of 13 genes, including five for antimicrobial peptides, in parallel biopsies was assessed with qRT-PCR. The composition of microbiota between UC and non-IBD differed significantly (PCoA,p= 0.001). UC children had a decrease in Bacteroidetes and an increase in several family-level taxa including Peptostreptococcaceae and Enterobacteriaceae, which correlated negatively with the expression of antimicrobial peptides REG3G and DEFB1, respectively. Enterobacteriaceae correlated positively with the expression siderophore binding protein LCN2 and Betaproteobacteria negatively with DEFB4A expression. The results indicate that reciprocal interaction of epithelial microbiota and defense mechanisms play a role in UC.
  • Kondelin, J.; Salokas, K.; Saarinen, L.; Ovaska, K.; Rauanheimo, H.; Plaketti, R.-M.; Hamberg, J.; Liu, X.; Yadav, L.; Gylfe, A.E.; Cajuso, T.; Hänninen, U.A.; Palin, K.; Ristolainen, H.; Katainen, R.; Kaasinen, E.; Tanskanen, T.; Aavikko, M.; Taipale, M.; Taipale, J.; Renkonen-Sinisalo, L.; Lepistö, A.; Koskensalo, S.; Böhm, J.; Mecklin, J.-P.; Ongen, H.; Dermitzakis, E.T.; Kilpivaara, O.; Vahteristo, P.; Turunen, M.; Hautaniemi, S.; Tuupanen, S.; Karhu, A.; Välimäki, N.; Varjosalo, M.; Pitkänen, E.; Aaltonen, L.A. (2018)
    Microsatellite instability (MSI) leads to accumulation of an excessive number of mutations in the genome, mostly small insertions and deletions. MSI colorectal cancers (CRCs), however, also contain more point mutations than microsatellite-stable (MSS) tumors, yet they have not been as comprehensively studied. To identify candidate driver genes affected by point mutations in MSI CRC, we ranked genes based on mutation significance while correcting for replication timing and gene expression utilizing an algorithm, MutSigCV. Somatic point mutation data from the exome kit-targeted area from 24 exome-sequenced sporadic MSI CRCs and respective normals, and 12 whole-genome-sequenced sporadic MSI CRCs and respective normals were utilized. The top 73 genes were validated in 93 additional MSI CRCs. The MutSigCV ranking identified several well-established MSI CRC driver genes and provided additional evidence for previously proposed CRC candidate genes as well as shortlisted genes that have to our knowledge not been linked to CRC before. Two genes, SMARCB1 and STK38L, were also functionally scrutinized, providing evidence of a tumorigenic role, for SMARCB1 mutations in particular. © 2018 The Authors. Published under the terms of the CC BY 4.0 license
  • Liang, Yipeng; Gerwin, Jan; Meyer, Axel; Kratochwil, Claudius F. (2020)
    The East African adaptive radiations of cichlid fishes are renowned for their diversity in coloration. Yet, the developmental basis of pigment pattern formation remains largely unknown. One of the most common melanic patterns in cichlid fishes are vertical bar patterns. Here we describe the ontogeny of this conspicuous pattern in the Lake Kyoga species Haplochromis latifasciatus. Beginning with the larval stages we tracked the formation of this stereotypic color pattern and discovered that its macroscopic appearance is largely explained by an increase in melanophore density and accumulation of melanin during the first 3 weeks post-fertilization. The embryonal analysis is complemented with cytological quantifications of pigment cells in adult scales and the dermis beneath the scales. In adults, melanic bars are characterized by a two to threefold higher density of melanophores than in the intervening yellow interbars. We found no strong support for differences in other pigment cell types such as xanthophores. Quantitative PCRs for twelve known pigmentation genes showed that expression of melanin synthesis genes tyr and tyrp1a is increased five to sixfold in melanic bars, while xanthophore and iridophore marker genes are not differentially expressed. In summary, we provide novel insights on how vertical bars, one of the most widespread vertebrate color patterns, are formed through dynamic control of melanophore density, melanin synthesis and melanosome dispersal.
  • Qin, Nanbing; Bayat, Ali-Reza; Trevisi, Erminio; Minuti, Andrea; Kairenius, Piia; Viitala, Sirja; Mutikainen, Mervi; Leskinen, Heidi; Elo, Kari Tapani; Kokkonen, Tuomo Juhani; Vilkki, Johanna (2018)
    To investigate the metabolic (.11, ! in the adipose tissue (AT) of dairy cows under milk fat depression (MFD), 30 cows were randomly allocated to a control diet, a conjugated linoleic acid (CLA)-supplemented diet, or a high-starch diet supplemented with a mixture of sunflower and fish oil (2:1; as HSO diet) from 1 to 112 d in milk. Performance of animals, milk yield, milk composition, energy balance, and blood metabolites were measured during lactation. Quantitative PCR analyses were conducted on the AT samples collected at wk 3 and 15 of lactation. The CLA and HSO diets considerably depressed milk fat yield and milk fat content at both wk 3 and 15 in the absence of significant changes in milk protein and lactose contents. In addition, the HSO diet lowered milk yield at wk 15 and decreased dry matter intake of cows from wk 3 to 15. Compared with the control, both CLA and HSO groups showed reduced body weight loss, improved energy balance, and decreased plasma concentrations of nonesterified fatty acids and beta-hydroxybutyrate at early lactation. The gene expression analyses reflected suppressed lipolysis in AT of the CLA and HSO groups compared with the control at wk 3, as suggested by the downregulation of hormone-sensitive lipase and fatty acid binding protein 4 and the upregulation of perilipin 2. In addition, the HSO diet promoted lipogenesis in AT at wk 15 through the upregulation of 1-acylglycerol-3-phosphate O-acyltransferase 2, mitochondria' glycerol-3-phosphate acyltransferase, perilipin 2, and peroxisome proliferator-activated receptor gamma. The CLA diet likely regulated insulin sensitivity in AT as it upregulated the transcription of various genes involved in insulin signaling, inflammatory responses, and ceramide metabolism, including protein kinase B2, nuclear factor kappa B1, toll-like receptor 4, caveolin 1, serine palmitoyltransferase long chain base subunit 1, and N-acylsphingosine amidohydrolase 1. In contrast, the HSO diet resulted in little or no change in the pathways relevant to insulin sensitivity. In conclusion, the CLA and HSO diets induced a shift in energy partitioning toward AT instead of mammary gland during lactation through the regulation of different pathways.
  • Salgado, Ana L.; Suchan, Tomasz; Pellissier, Loic; Rasmann, Sergio; Ducrest, Anne-Lyse; Alvarez, Nadir (2016)
    Elevation gradients impose large differences in abiotic and biotic conditions over short distances, in turn, likely driving differences in gene expression more than would genetic variation per se, as natural selection and drift are less likely to fix alleles at such a narrow spatial scale. As elevation increases, the pressure exerted on plants by herbivores and on arthropod herbivores by predators decreases, and organisms spanning the elevation gradient are thus expected to show lower levels of defence at high elevation. The alternative hypothesis, based on the optimal defence theory, is that defence allocation should be higher in low-resource habitats such as those at high elevation, due to higher costs associated with tissue replacement. In this study, we analyse variation with elevation in (i) defence compound content in the plant Lotus corniculatus and (ii) gene expression associated with defence against predators in the specific phytophagous moth, Zygaena filipendulae. Both species produce cyanogenic glycosides (CNglcs) such as lotaustralin and linamarin as defence mechanisms, with the moth, in addition, being able to sequester CNglcs from its host plant. Specifically, we tested the assumption that the defence-associated phenotype in plants and the gene expression in the insect herbivore should covary between low-and high-elevation environments. We found that L. corniculatus accumulated more CNglcs at high elevation, a result in agreement with the optimal defence theory. By contrast, we found that the levels of expression in the defence genes of Z. filipendulae larvae were not related to the CNglc content of their host plant. Overall, expression levels were not correlated with elevation either, with the exception of the UGT33A1 gene, which showed a marginally significant trend towards higher expression at high elevation when using a simple statistical framework. These results suggest that the defence phenotype of plants against herbivores, and subsequent herbivore sequestration machineries and de novo production, are based on a complex network of interactions.
  • Wu, Chen; Twort, Victoria G; Newcomb, Richard D; Buckley, Thomas R (2021)
    Some animal groups, such as stick insects (Phasmatodea), have repeatedly evolved alternative reproductive strategies, including parthenogenesis. Genomic studies have found modification of the genes underlying meiosis exists in some of these animals. Here we examine the evolution of copy number, evolutionary rate, and gene expression in candidate meiotic genes of the New Zealand geographic parthenogenetic stick insect Clitarchus hookeri. We characterized 101 genes from a de novo transcriptome assembly from female and male gonads that have homology with meiotic genes from other arthropods. For each gene we determined copy number, the pattern of gene duplication relative to other arthropod orthologs, and the potential for meiosis-specific expression. There are five genes duplicated in C hookers; including one also duplicated in the stick insect Timema cristinae, that are not or are uncommonly duplicated in other arthropods. These included two sister chromatid cohesion associated genes (SA2 and SCC2), a recombination gene (HOPI), an RNA-silencing gene (AGO2) and a cell-cycle regulation gene (WEE1). Interestingly, WEE1 and SA2 are also duplicated in the cyclical parthenogenetic aphid Acyrthosiphon pisum and Daphnia duplex, respectively, indicating possible roles in the evolution of reproductive mode. Three of these genes (SA2, SCC2, and WEE1) have one copy displaying gonad-specific expression. All genes, with the exception of WEE1, have significantly different nonsynonymous/synonymous ratios between the gene duplicates, indicative of a shift in evolutionary constraints following duplication. These results suggest that stick insects may have evolved genes with novel functions in gamete production by gene duplication.
  • Jernström, Sandra; Hongisto, Vesa; Leivonen, Suvi-Katri; Due, Eldri Undlien; Tadele, Dagim Shiferaw; Edgren, Henrik; Kallioniemi, Olli; Perälä, Merja; Mlandsmo, Gunhild Mari; Sahlberg, Kristine Kleivi (2017)
    Background: Approximately 15%-20% of all diagnosed breast cancers are characterized by amplified and overexpressed HER2 (= ErbB2). These breast cancers are aggressive and have a poor prognosis. Although improvements in treatment have been achieved after the introduction of trastuzumab and lapatinib, many patients do not benefit from these drugs. Therefore, in-depth understanding of the mechanisms behind the treatment responses is essential to find alternative therapeutic strategies. Materials and methods: Thirteen HER2 positive breast cancer cell lines were screened with 22 commercially available compounds, mainly targeting proteins in the ErbB2-signaling pathway, and molecular mechanisms related to treatment sensitivity were sought. Cell viability was measured, and treatment responses between the cell lines were compared. To search for response predictors and genomic and transcriptomic profiling, PIK3CA mutations and PTEN status were explored and molecular features associated with drug sensitivity sought. Results: The cell lines were divided into three groups according to the growth-retarding effect induced by trastuzumab and lapatinib. Interestingly, two cell lines insensitive to trastuzumab (KPL4 and SUM190PT) showed sensitivity to an Akt1/2 kinase inhibitor. These cell lines had mutation in PIK3CA and loss of PTEN, suggesting an activated and druggable Akt-signaling pathway. Expression levels of five genes (CDC42, MAPK8, PLCG1, PTK6, and PAK6) were suggested as predictors for the Akt1/2 kinase-inhibitor response. Conclusion: Targeting the Akt-signaling pathway shows promise in cell lines that do not respond to trastuzumab. In addition, our results indicate that several molecular features determine the growth-retarding effects induced by the drugs, suggesting that parameters other than HER2 amplification/expression should be included as markers for therapy decisions.
  • Koopen, Annefleur; Witjes, Julia; Wortelboer, Koen; Majait, Soumia; Prodan, Andrei; Levin, Evgeni; Herrema, Hilde; Winkelmeijer, Maaike; Aalvink, Steven; Bergman, Jacques J. G. H. M.; Havik, Stephan; Hartmann, Bolette; Levels, Han; Bergh, Per-Olof; van Son, Jamie; Balvers, Manon; Bastos, Diogo Mendes; Stroes, Erik; Groen, Albert K.; Henricsson, Marcus; Kemper, Ellis Marleen; Holst, Jens; Strauch, Christopher M.; Hazen, Stanley L.; Backhed, Fredrik; De Vos, Willem M.; Nieuwdorp, Max; Rampanelli, Elena (2022)
    Objective Although gut dysbiosis is increasingly recognised as a pathophysiological component of metabolic syndrome (MetS), the role and mode of action of specific gut microbes in metabolic health remain elusive. Previously, we identified the commensal butyrogenic Anaerobutyricum soehngenii to be associated with improved insulin sensitivity in subjects with MetS. In this proof-of-concept study, we investigated the potential therapeutic effects of A. soehngenii L2-7 on systemic metabolic responses and duodenal transcriptome profiles in individuals with MetS. Design In this randomised double-blind placebo-controlled cross-over study, 12 male subjects with MetS received duodenal infusions of A. soehngenii/ placebo and underwent duodenal biopsies, mixed meal tests (6 hours postinfusion) and 24-hour continuous glucose monitoring. Results A. soehngenii treatment provoked a markedly increased postprandial excursion of the insulinotropic hormone glucagon-like peptide 1 (GLP-1) and an elevation of plasma secondary bile acids, which were positively associated with GLP-1 levels. Moreover, A. soehngenii treatment robustly shaped the duodenal expression of 73 genes, with the highest fold induction in the expression of regenerating islet-protein 1B (REG1B)-encoding gene. Strikingly, duodenal REG1B expression positively correlated with GLP-1 levels and negatively correlated with peripheral glucose variability, which was significantly diminished in the 24 hours following A. soehngenii intake. Mechanistically, Reg1B expression is induced upon sensing butyrate or bacterial peptidoglycan. Importantly, A. soehngenii duodenal administration was safe and well tolerated. Conclusions A single dose of A. soehngenii improves peripheral glycaemic control within 24 hours; it specifically stimulates intestinal GLP-1 production and REG1B expression. Further studies are needed to delineate the specific pathways involved in REG1B induction and function in insulin sensitivity.