| 1. |
- Chaudhari, Aditi, et al.
(författare)
-
Hepatic deletion of p110α and p85α results in insulin resistance despite sustained IRS1-associated phosphatidylinositol kinase activity
- 2017
-
Ingår i: F1000 Research. - : Faculty of 1000 Ltd.. - 2046-1402 .- 1759-796X. ; 6
-
Tidskriftsartikel (refereegranskat)abstract
- Background: Class IA phosphatidylinositol-4,5-bisphosphate 3-kinase (PI3K) is an integral mediator of insulin signaling. The p110 catalytic and p85 regulatory subunits of PI3K are the products of separate genes, and while they come together to make the active heterodimer, they have opposing roles in insulin signaling and action. Deletion of hepatic p110α results in an impaired insulin signal and severe insulin resistance, whereas deletion of hepatic p85α results in improved insulin sensitivity due to sustained levels of phosphatidylinositol (3,4,5)-trisphosphate. Here, we created mice with combined hepatic deletion of p110α and p85α (L-DKO) to study the impact on insulin signaling and whole body glucose homeostasis.Methods: Six-week old male flox control and L-DKO mice were studied over a period of 18 weeks, during which weight and glucose levels were monitored, and glucose tolerance tests, insulin tolerance test and pyruvate tolerance test were performed. Fasting insulin, insulin signaling mediators, PI3K activity and insulin receptor substrate (IRS)1-associated phosphatidylinositol kinase activity were examined at 10 weeks. Liver, muscle and white adipose tissue weight was recorded at 10 weeks and 25 weeks.Results: The L-DKO mice showed a blunted insulin signal downstream of PI3K, developed markedly impaired glucose tolerance, hyperinsulinemia and had decreased liver and adipose tissue weights. Surprisingly, however, these mice displayed normal hepatic glucose production, normal insulin tolerance, and intact IRS1-associated phosphatidylinositol kinase activity without compensatory upregulated signaling of other classes of PI3K.Conclusions: The data demonstrate an unexpectedly overall mild metabolic phenotype of the L-DKO mice, suggesting that lipid kinases other than PI3Ks might partially compensate for the loss of p110α/p85α by signaling through other nodes than Akt/Protein Kinase B.
|
|
| 2. |
- Deland, Lily, et al.
(författare)
-
Novel TPR::ROS1 Fusion Gene Activates MAPK, PI3K and JAK/STAT Signaling in an Infant-type Pediatric Glioma.
- 2022
-
Ingår i: Cancer genomics & proteomics. - : Anticancer Research USA Inc.. - 1790-6245 .- 1109-6535. ; 19:6, s. 711-726
-
Tidskriftsartikel (refereegranskat)abstract
- Although fusion genes involving the proto-oncogene receptor tyrosine kinase ROS1 are rare in pediatric glioma, targeted therapies with small inhibitors are increasingly being approved for histology-agnostic fusion-positive solid tumors.Here, we present a 16-month-old boy, with a brain tumor in the third ventricle. The patient underwent complete resection but relapsed two years after diagnosis and underwent a second operation. The tumor was initially classified as a low-grade glioma (WHO grade 2); however, methylation profiling suggested the newly WHO-recognized type: infant-type hemispheric glioma. To further refine the molecular background, and search for druggable targets, whole genome (WGS) and whole transcriptome (RNA-Seq) sequencing was performed.Concomitant WGS and RNA-Seq analysis revealed several segmental gains and losses resulting in complex structural rearrangements and fusion genes. Among the top-candidates was a novel TPR::ROS1 fusion, for which only the 3' end of ROS1 was expressed in tumor tissue, indicating that wild type ROS1 is not normally expressed in the tissue of origin. Functional analysis by Western blot on protein lysates from transiently transfected HEK293 cells showed the TPR::ROS1 fusion gene to activate the MAPK-, PI3K- and JAK/STAT- pathways through increased phosphorylation of ERK, AKT, STAT and S6. The downstream pathway activation was also confirmed by immunohistochemistry on tumor tissue slides from the patient.We have mapped the activated oncogenic pathways of a novel ROS1-fusion gene and broadened the knowledge of the newly recognized infant-type glioma subtype. The finding facilitates suitable targeted therapies for the patient in case of relapse.
|
|
| 3. |
- Gustafson, Deborah R.
(författare)
-
Adipose Tissue Complexities in Dyslipidemias
- 2019
-
Ingår i: Dyslipidemia. - London : IntechOpen. - 9781839680045 - 9781839680038 - 9781839680052 ; , s. 1-22
-
Bokkapitel (refereegranskat)abstract
- Adipose tissue is the largest organ in the human body and, in excess, contributes to dyslipidemias and the dysregulation of other vascular and metabolic processes. Adipose tissue is heterogeneous, comprised of several cell types based on morphology, cellular age, and endocrine and paracrine function. Adipose tissue depots are also regional, primarily due to sex differences and genetic variation. Adipose tissue is also characterized as subcutaneous vs. visceral. In addition, fatty deposits exist outside of adipose tissue, such as those surrounding the heart, or as infiltration of skeletal muscle. This review focuses on adipose tissue and its contribution to dyslipidemias. Dyslipidemias are defined as circulating blood lipid levels that are too high or altered. Lipids include both traditional and nontraditional species. Leaving aside traditional definitions, adipose tissue contributes to dyslipidemias in a myriad of ways. To address a small portion of this topic, we reviewed (a) adipose tissue location and cell types, (b) body composition, (c) endocrine adipose, (d) the fat-brain axis, and (e) genetic susceptibility. The influence of these complex aspects of adipose tissue on dyslipidemias and human health, illustrating that, once again, that adipose tissue is a quintessential, multifunctional tissue of the human body, will be summarized.
|
|
| 4. |
- Chaudhari, Aditi, et al.
(författare)
-
p110α hot spot mutations E545K and H1047R exert metabolic reprogramming independently of p110α kinase activity
- 2015
-
Ingår i: Molecular and Cellular Biology. - : American Society for Microbiology. - 0270-7306 .- 1098-5549. ; 35:19, s. 3258-3273
-
Tidskriftsartikel (refereegranskat)abstract
- The phosphatidylinositol-4,5-bisphosphate 3-kinase (PI3K) catalytic subunit p110α is the most frequently mutated kinase in human cancer, and the hot spot mutations E542K, E545K, and H1047R are the most common mutations in p110α. Very little is known about the metabolic consequences of the hot spot mutations of p110α in vivo. In this study, we used adenoviral gene transfer in mice to investigate the effects of the E545K and H1047R mutations on hepatic and whole-body glucose metabolism. We show that hepatic expression of these hot spot mutations results in rapid hepatic steatosis, paradoxically accompanied by increased glucose tolerance, and marked glycogen accumulation. In contrast, wild-type p110α expression does not lead to hepatic accumulation of lipids or glycogen despite similar degrees of upregulated glycolysis and expression of lipogenic genes. The reprogrammed metabolism of the E545K and H1047R p110α mutants was surprisingly not dependent on altered p110α lipid kinase activity.
|
|
| 5. |
- Fransson, Susanne, 1975, et al.
(författare)
-
High level of p37δ-mRNA relative to p110δ-mRNA in neuroblastoma tumors correlates with poor patient survival
- 2013
-
Ingår i: Medical Oncology. - : Springer Science+Business Media B.V.. - 1357-0560 .- 1559-131X. ; 30:4
-
Tidskriftsartikel (refereegranskat)abstract
- Alterations in the PI3K/Akt pathway, a pathway that promotes proliferation and oncogenic transformation, are common in various cancers. In neuroblastoma, activation of Akt is correlated with aggressive disease although mutations in genes of this pathway are rare. Previous findings include a few mutations in PIK3CD, the gene encoding PI3K catalytic subunit delta, p110delta. We recently reported that an alternatively spliced form of p110delta, called p37delta, had cell proliferative properties and was over-expressed in ovarian and colorectal tumors. Here, we investigated p37delta in neuroblastoma primary tumors of different stages using qPCR (TaqMan) for gene expression analysis (46 samples) and Western blot for protein analysis (22 samples). Elevated levels of both p37delta-mRNA and p110delta-mRNA were detected in metastasizing neuroblastoma tumors compared to normal adrenal gland (P<0.05), and higher expression of p37delta-mRNA relative to p110delta-mRNA in neuroblastoma non-survivor patients compared to survivors (P<0.01). p37delta-Protein levels but not p110delta levels correlated with increased pAKT(T308) and pERK levels. The p37delta-mRNA levels did not correlate with the protein levels, indicating major regulation at the translational/protein level. Deregulation of signaling pathways is a hallmark of cancer development. Here, we show that p37delta, a kinase-dead isoform of the PI3K catalytic subunit p110delta, is over-expressed in neuroblastoma tumors, and that it correlates with the activation of both PI3K/Akt- and RAS-signaling pathways.
|
|
| 6. |
- Jurcevic, Sanja, 1971-, et al.
(författare)
-
Bioinformatics analysis of miRNAs in the neuroblastoma 11q-deleted region reveals a role of miR-548l in both 11q-deleted and MYCN amplified tumour cells
- 2022
-
Ingår i: Scientific Reports. - : Springer Nature. - 2045-2322. ; 12:1
-
Tidskriftsartikel (refereegranskat)abstract
- Neuroblastoma is a childhood tumour that is responsible for approximately 15% of all childhood cancer deaths. Neuroblastoma tumours with amplification of the oncogene MYCN are aggressive, however, another aggressive subgroup without MYCN amplification also exists; rather, they have a deleted region at chromosome arm 11q. Twenty-six miRNAs are located within the breakpoint region of chromosome 11q and have been checked for a possible involvement in development of neuroblastoma due to the genomic alteration. Target genes of these miRNAs are involved in pathways associated with cancer, including proliferation, apoptosis and DNA repair. We could show that miR-548l found within the 11q region is downregulated in neuroblastoma cell lines with 11q deletion or MYCN amplification. In addition, we showed that the restoration of miR-548l level in a neuroblastoma cell line led to a decreased proliferation of these cells as well as a decrease in the percentage of cells in the S phase. We also found that miR-548l overexpression suppressed cell viability and promoted apoptosis, while miR-548l knockdown promoted cell viability and inhibited apoptosis in neuroblastoma cells. Our results indicate that 11q-deleted neuroblastoma and MYCN amplified neuroblastoma coalesce by downregulating miR-548l.
|
|
| 7. |
- Sundell, Timothy, et al.
(författare)
-
Single-cell RNA sequencing analyses : interference by the genes that encode the B-cell and T-cell receptors
- 2023
-
Ingår i: Briefings in Functional Genomics & Proteomics. - : Oxford University Press. - 2041-2649 .- 2041-2657. ; 22:3, s. 263-273
-
Tidskriftsartikel (refereegranskat)abstract
- B and T cells are integral parts of the immune system and are implicated in many diseases, e.g. autoimmunity. Towards understanding the biology of B and T cells and subsets thereof, their transcriptomes can be analyzed using single-cell RNA sequencing. In some studies, the V(D)J transcripts encoding the variable regions of the B- and T-cell antigen receptors have been removed before the analyses. However, a systematic analysis of the effects of including versus excluding these genes is currently lacking. We have investigated the effects of these transcripts on unsupervised clustering and down-stream analyses of single-cell RNA sequencing data from B and T cells. We found that exclusion of the B-/T-cell receptor genes prior to unsupervised clustering resulted in clusters that represented biologically meaningful subsets, such as subsets of memory B and memory T cells. Furthermore, pseudo-time and trajectory inference analyses of early B-lineage cells resulted in a developmental pathway from progenitor to immature B cells. In contrast, when the B-/T-cell receptor genes were not removed, with the PCs used for clustering consisting of up to 70% V-genes, this resulted in some clusters being defined exclusively by V-gene segments. These did not represent biologically meaningful subsets; for instance in the early B-lineage cells, these clusters contained cells representing all developmental stages. Thus, in studies of B and T cells, to derive biologically meaningful results, it is imperative to remove the gene sequences that encode B- and T-cell receptors.
|
|
| 8. |
- Kokosar, Milana, et al.
(författare)
-
A Single Bout of Electroacupuncture Remodels Epigenetic and Transcriptional Changes in Adipose Tissue in Polycystic Ovary Syndrome
- 2018
-
Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 8:1
-
Tidskriftsartikel (refereegranskat)abstract
- A single bout of electroacupuncture results in muscle contractions and increased whole body glucose uptake in women with polycystic ovary syndrome (PCOS). Women with PCOS have transcriptional and epigenetic alterations in the adipose tissue and we hypothesized that electroacupuncture induces epigenetic and transcriptional changes to restore metabolic alterations. Twenty-one women with PCOS received a single bout of electroacupuncture, which increased the whole body glucose uptake. In subcutaneous adipose tissue biopsies, we identified treatment-induced expression changes of 2369 genes (Q < 0.05) and DNA methylation changes of 7055 individual genes (Q = 0.11). The largest increase in expression was observed for FOSB (2405%), and the largest decrease for LOC100128899 (54%). The most enriched pathways included Acute phase response signaling and LXR/RXR activation. The DNA methylation changes ranged from 1-16%, and 407 methylation sites correlated with gene expression. Among genes known to be differentially expressed in PCOS, electroacupuncture reversed the expression of 80 genes, including PPAR gamma and ADIPOR2. Changes in the expression of Nr4 alpha 2 and Junb are reversed by adrenergic blockers in rats demonstrating that changes in gene expression, in part, is due to activation of the sympathetic nervous system. In conclusion, low-frequency electroacupuncture with muscle contractions remodels epigenetic and transcriptional changes that elicit metabolic improvement.
|
|
| 9. |
- Rosenhahn, Erik, et al.
(författare)
-
Bi-allelic loss-of-function variants in PPFIBP1 cause a neurodevelopmental disorder with microcephaly, epilepsy, and periventricular calcifications
- 2022
-
Ingår i: American Journal of Human Genetics. - : Cell Press. - 0002-9297 .- 1537-6605. ; 109:8, s. 1421-1435
-
Tidskriftsartikel (refereegranskat)abstract
- PPFIBP1 encodes for the liprin-β1 protein, which has been shown to play a role in neuronal outgrowth and synapse formation in Drosophila melanogaster. By exome and genome sequencing, we detected nine ultra-rare homozygous loss-of-function variants in 16 individuals from 12 unrelated families. The individuals presented with moderate to profound developmental delay, often refractory early-onset epilepsy, and progressive microcephaly. Further common clinical findings included muscular hyper- and hypotonia, spasticity, failure to thrive and short stature, feeding difficulties, impaired vision, and congenital heart defects. Neuroimaging revealed abnormalities of brain morphology with leukoencephalopathy, ventriculomegaly, cortical abnormalities, and intracranial periventricular calcifications as major features. In a fetus with intracranial calcifications, we identified a rare homozygous missense variant that by structural analysis was predicted to disturb the topology of the SAM domain region that is essential for protein-protein interaction. For further insight into the effects of PPFIBP1 loss of function, we performed automated behavioral phenotyping of a Caenorhabditis elegans PPFIBP1/hlb-1 knockout model, which revealed defects in spontaneous and light-induced behavior and confirmed resistance to the acetylcholinesterase inhibitor aldicarb, suggesting a defect in the neuronal presynaptic zone. In conclusion, we establish bi-allelic loss-of-function variants in PPFIBP1 as a cause of an autosomal recessive severe neurodevelopmental disorder with early-onset epilepsy, microcephaly, and periventricular calcifications.
|
|
| 10. |
- Ghosheh, Nidal, 1975-, et al.
(författare)
-
Human Pluripotent Stem Cell-Derived Hepatocytes Show Higher Transcriptional Correlation with Adult Liver Tissue than with Fetal Liver Tissue
- 2020
-
Ingår i: ACS Omega. - : American Chemical Society (ACS). - 2470-1343. ; 5:10, s. 4816-4827
-
Tidskriftsartikel (refereegranskat)abstract
- Human pluripotent stem cell-derived hepatocytes (hPSC-HEP) display many properties of mature hepatocytes, including expression of important genes of the drug metabolizing machinery, glycogen storage, and production of multiple serum proteins. To this date, hPSC-HEP do not, however, fully recapitulate the complete functionality of in vivo mature hepatocytes. In this study, we applied versatile bioinformatic algorithms, including functional annotation and pathway enrichment analyses, transcription factor binding-site enrichment, and similarity and correlation analyses, to datasets collected from different stages during hPSC-HEP differentiation and compared these to developmental stages and tissues from fetal and adult human liver. Our results demonstrate a high level of similarity between the in vitro differentiation of hPSC-HEP and in vivo hepatogenesis. Importantly, the transcriptional correlation of hPSC-HEP with adult liver (AL) tissues was higher than with fetal liver (FL) tissues (0.83 and 0.70, respectively). Functional data revealed mature features of hPSC-HEP including cytochrome P450 enzymes activities and albumin secretion. Moreover, hPSC-HEP showed expression of many genes involved in drug absorption, distribution, metabolism, and excretion. Despite the high similarities observed, we identified differences of specific pathways and regulatory players by analyzing the gene expression between hPSC-HEP and AL. These findings will aid future intervention and improvement of in vitro hepatocyte differentiation protocol in order to generate hepatocytes displaying the complete functionality of mature hepatocytes. Finally, on the transcriptional level, our results show stronger correlation and higher similarity of hPSC-HEP to AL than to FL. In addition, potential targets for further functional improvement of hPSC-HEP were also identified.
|
|
