Local and systemic metabolic alterations in brain, plasma, and liver of rats in response to aging and ischemic stroke, as detected by nuclear magnetic resonance (NMR) spectroscopy

Metabolic dysfunction impacts stroke incidence and outcome. However, the intricate association between altered metabolic program due to aging, and focal ischemia in brain, circulation, and peripheral organs is not completely elucidated. Here we identified locally and systemically altered metabolites in brain, liver, and plasma as a result of normal aging, ischemic-stroke, and extended time of reperfusion injury. Comprehensive quantitative metabolic profiling was carried out using nuclear magnetic resonance spectroscopy. Aging, but healthy rats showed significant metabolic alterations in the brain, but only a few metabolic changes in the liver and plasma as compared to younger rats. But, ischemic stroke altered metabolites significantly in liver and plasma of older rats during early acute phase. Major metabolic changes were also seen in the brains of younger rats following ischemic stroke during early acute phase of injury. We further report that metabolic changes occur sequentially in a tissue specific manner during extended reperfusion time of late repair phase. First metabolic alterations occurred in brain due to local injury. Next, changes in circulating metabolites in plasma occurred during acute-repair phase transition time. Lastly, the delayed systemic effect was seen in the peripheral organ, liver that exhibited significant and persistent changes in selected metabolites during later reperfusion time. The metabolic pathways involved in energy/glucose, and amino acid metabolism, inflammation, and oxidative stress were mainly altered as a result of aging and ischemia/reperfusion. Biomarker analysis revealed citrate, lysine, and tyrosine as potential age-independent blood metabolic biomarkers of ischemia/reperfusion. Overall, our study elucidates the complex network of metabolic events as a function of normal aging and acute stroke. We further provide evidence for a clear transition from local to systemic metabolic dysfunction due to ischemic injury in a time dependent manner, which may altogether greatly impact the post-stroke outcome

A mutation in transmembrane protein 135 impairs lipid metabolism in mouse eyecups

Aging is a significant factor in the development of age-related diseases but how aging disrupts cellular homeostasis to cause age-related retinal disease is unknown. Here, we further our studies on transmembrane protein 135 (Tmem135), a gene involved in retinal aging, by examining the transcriptomic profiles of wild-type, heterozygous and homozygous Tmem135 mutant posterior eyecup samples through RNA sequencing (RNA-Seq). We found significant gene expression changes in both heterozygous and homozygous Tmem135 mutant mouse eyecups that correlate with visual function deficits. Further analysis revealed that expression of many genes involved in lipid metabolism are changed due to the Tmem135 mutation. Consistent with these changes, we found increased lipid accumulation in mutant Tmem135 eyecup samples. Since mutant Tmem135 mice have similar ocular pathologies as human age-related macular degeneration (AMD) eyes, we compared our homozygous Tmem135 mutant eyecup RNA-Seq dataset with transcriptomic datasets of human AMD donor eyes. We found similar changes in genes involved in lipid metabolism between the homozygous Tmem135 mutant eyecups and AMD donor eyes. Our study suggests that the Tmem135 mutation affects lipid metabolism as similarly observed in human AMD eyes, thus Tmem135 mutant mice can serve as a good model for the role of dysregulated lipid metabolism in AMD

CMV, EBV, JCV and BKV infection and outcome following kidney transplantation in children initiated on a corticosteroid-minimisation immunosuppressive regimen

Background Modern immunosuppressive regimens in paediatric kidney transplant recipients have contributed to improved long-term allograft survival, but at the expense of an increased incidence of viral infections. Here, we describe, for the first time, the incidence, risk factors and clinical outcome of CMV, EBV, BKV and JCV viraemia in a cohort of paediatric allograft recipients treated with a corticosteroid-minimisation immunosuppressive regimen (CMR). Methods: We retrospectively analysed 98 children treated with a CMR (basiliximab induction, corticosteroids until day 4, long-term tacrolimus and mycophenolate mofetil), who received a kidney transplant in our centre between 2009 and 2019. Results: Over the first 4 years post-transplant, the incidences of viraemia were as follows: CMV, 25.5%; EBV, 52.0%; JCV, 16.3%; BKV, 26.5%. Younger children at time of transplant were more likely to develop EBV and BKV viraemia. EBV viraemia was also associated with a regimen involving corticosteroids, but lacking MMF. Recipient CMV serology predicted the development of EBV, BKV and CMV viraemia. Fifty-six percent of CMV viraemia episodes in high-risk patients occurred whilst the graft recipients were still receiving anti-viral prophylaxis or within 3 months of cessation. There was no difference in graft function at latest follow-up between those with and without viraemia. Conclusions: Judicious monitoring of viraemia, coupled with timely clinical intervention, can result in similar long-term outcomes for graft recipients compared to controls. The high incidence of CMV viraemia observed within a short period of cessation of anti-viral prophylaxis supports an extension of the length of prophylactic treatment in high-risk allograft recipients

Transforming traditional teaching laboratories for effective remote delivery—A review

Teaching laboratories form an essential component of any engineering education. They enable students to participate in various stages of experiential learning including conceptualization and experimentation followed by reflection, analysis and interpretation of data. However, operating teaching laboratories with social distancing measures poses significant logistical and safety challenges, and alternative modes of delivery may be a realistic way forward in adapting engineering curricula to the post COVID-19 world. Best practices from spaces such as distance learning and virtual / remote laboratories can be leveraged to facilitate educators’ responses. This review is aimed at identifying evidence-based approaches for transforming hands-on labs into virtual or remote operation to achieve desired learning outcomes without compromising on soft skills and student self-efficacy. A critical review of the recent literature on delivering STEMM education laboratories in either a virtual or remote setting or a combination of both is presented here. Commonly emerging approaches are identified and strategies to implement remote or mixed-mode (a combination of remote and traditional lab components) delivery are highlighted. The value of these approaches to the educator is assessed based on claimed learning outcomes, availability of resources, technology, scheduling, and cost factors

Dynamic regulation of hypoxia-inducible factor-1α activity is essential for normal B cell development

B lymphocyte development and selection are central to adaptive immunity and self-tolerance. These processes require B cell receptor (BCR) signaling and occur in bone marrow, an environment with variable hypoxia, but whether hypoxia-inducible factor (HIF) is involved is unknown. We show that HIF activity is high in human and murine bone marrow pro-B and pre-B cells and decreases at the immature B cell stage. This stage-specific HIF suppression is required for normal B cell development because genetic activation of HIF-1α in murine B cells led to reduced repertoire diversity, decreased BCR editing and developmental arrest of immature B cells, resulting in reduced peripheral B cell numbers. HIF-1α activation lowered surface BCR, CD19 and B cell–activating factor receptor and increased expression of proapoptotic BIM. BIM deletion rescued the developmental block. Administration of a HIF activator in clinical use markedly reduced bone marrow and transitional B cells, which has therapeutic implications. Together, our work demonstrates that dynamic regulation of HIF-1α is essential for normal B cell development

Dynamic regulation of hypoxia-inducible factor-1 alpha activity is essential for normal B cell development

B lymphocyte development and selection are central to adaptive immunity and self-tolerance. These processes require B cell receptor (BCR) signaling and occur in bone marrow, an environment with variable hypoxia, but whether hypoxia-inducible factor (HIF) is involved is unknown. We show that HIF activity is high in human and murine bone marrow pro-B and pre-B cells and decreases at the immature B cell stage. This stage-specific HIF suppression is required for normal B cell development because genetic activation of HIF-1α in murine B cells led to reduced repertoire diversity, decreased BCR editing and developmental arrest of immature B cells, resulting in reduced peripheral B cell numbers. HIF-1α activation lowered surface BCR, CD19 and B cell–activating factor receptor and increased expression of proapoptotic BIM. BIM deletion rescued the developmental block. Administration of a HIF activator in clinical use markedly reduced bone marrow and transitional B cells, which has therapeutic implications. Together, our work demonstrates that dynamic regulation of HIF-1α is essential for normal B cell development

A review on metabolomics data analysis for cancer applications

Cancer cells undergo metabolic changes that contribute to tumorigenesis, which can be determined using metabolomics data produced by techniques such as nuclear magnetic resonance and mass spectroscopy, and analyzed through statistical and machine learning methods. Since these data represent well the metabolic phenotype of these cells, they are very relevant in cancer research, to better understand tumour cells metabolism and help in efforts of biomarker and drug target discovery. This mini-review focuses on data analysis methods that are commonly used to extract knowledge from cancer metabolomics data, such as univariate analysis and supervised and unsupervised multivariate data analysis, including clustering and machine learning.This work is co-funded by the North Portugal Regional Operational Programme, under the “Portugal 2020”, through the European Regional Development Fund (ERDF), within project SISBI- RefaNORTE-01-0247-FEDER-003381. This study was also supported by the Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UID/BIO/04469/2013 unit and COMPETE 2020 (POCI-01-0145-FEDER-006684) and BioTecNorte operation (NORTE-01-0145-FEDER-000004) funded by European Regional Development Fund under the scope of Norte2020 - Programa Operacional Regional do Norte.info:eu-repo/semantics/publishedVersio

The Poly (ADP-Ribose) Polymerase Inhibitor Veliparib and Radiation Cause Significant Cell Line Dependent Metabolic Changes in Breast Cancer Cells

Breast tumors are characterized into subtypes based on their surface marker expression, which affects their prognosis and treatment. Poly (ADP-ribose) polymerase (PARP) inhibitors have shown promising results in clinical trials, both as single agents and in combination with other chemotherapeutics, in several subtypes of breast cancer patients. Here, we used NMR-based metabolomics to probe cell line-specific effects of the PARP inhibitor Veliparib and radiation on metabolism in three breast cancer cell lines. Our data reveal several cell line-independent metabolic changes upon PARP inhibition. Pathway enrichment and topology analysis identified that nitrogen metabolism, glycine, serine and threonine metabolism, aminoacyl-tRNA biosynthesis and taurine and hypotaurine metabolism were enriched after PARP inhibition in all three breast cancer cell lines. Many metabolic changes due to radiation and PARP inhibition were cell line-dependent, highlighting the need to understand how these treatments affect cancer cell response via changes in metabolism. Finally, both PARP inhibition and radiation induced a similar metabolic responses in BRCA-mutant HCC1937 cells, but not in MCF7 and MDAMB231 cells, suggesting that radiation and PARP inhibition share similar interactions with metabolic pathways in BRCA mutant cells. Our study emphasizes the importance of differences in metabolic responses to cancer treatments in different subtypes of cancers