Fbxo7 promotes Cdk6 activity to inhibit PFKP and glycolysis in T cells.

Deregulated Fbxo7 expression is associated with many pathologies, including anaemia, male sterility, cancer, and Parkinson's disease, demonstrating its critical role in a variety of cell types. Although Fbxo7 is an F-box protein that recruits substrates for SCF-type E3 ubiquitin ligases, it also promotes the formation of cyclin D/Cdk6/p27 complexes in an E3-ligase independent fashion. We discovered PFKP, the major gatekeeper of glycolysis, in a screen for Fbxo7 substrates. PFKP has been previously shown to be a critical substrate of Cdk6 for the viability of T-ALL cells. We investigated the molecular relationships between Fbxo7, Cdk6 and PFKP, and the functional effect Fbxo7 has on T cell metabolism, viability, and activation. Fbxo7 promotes Cdk6-independent ubiquitination and Cdk6-dependent phosphorylation of PFKP. Importantly Fbxo7-deficient cells have reduced Cdk6 activity, and haematopoietic and lymphocytic cell lines show a significant dependency on Fbxo7. Compared to WT cells, CD4+ T cells with reduced Fbxo7 expression show increased glycolysis, despite lower cell viability and activation levels. Metabolomic studies of activated CD4+ T cells confirm increased glycolytic flux in Fbxo7-deficient cells, as well as altered nucleotide biosynthesis and arginine metabolism. We show Fbxo7 expression is glucose-responsive at the mRNA and protein level, and we propose Fbxo7 inhibits PFKP and glycolysis via its activation of Cdk6.

EhVps23: A Component of ESCRT-I That Participates in Vesicular Trafficking and Phagocytosis of Entamoeba histolytica

The endosomal sorting complex required for transport (ESCRT) is formed by ESCRT-0, ESCRT-I, ESCRT-II, ESCRT-III complexes, and accessory proteins. It conducts vesicular trafficking in eukaryotes through the formation of vesicles and membrane fission and fusion events. The trophozoites of Entamoeba histolytica, the protozoan responsible for human amoebiasis, presents an active membrane movement in basal state that increases during phagocytosis and tissue invasion. ESCRT-III complex has a pivotal role during these events, but ESCRT-0, ESCRT-I and ESCRT-II have been poorly studied. Here, we unveiled the E. histolytica ESCRT-I complex and its implication in vesicular trafficking and phagocytosis, as well as the molecular relationships with other phagocytosis-involved molecules. We found a gene encoding for a putative EhVps23 protein with the ubiquitin-binding and Vps23 core domains. In basal state, it was in the plasma membrane, cytoplasmic vesicles and multivesicular bodies, whereas during phagocytosis it was extensively ubiquitinated and detected in phagosomes and connected vesicles. Docking analysis, immunoprecipitation assays and microscopy studies evidenced its interaction with EhUbiquitin, EhADH, EhVps32 proteins, and the lysobisphosphatidic acid phospholipid. The knocking down of the Ehvps23 gene resulted in lower rates of phagocytosis. Our results disclosed the concert of finely regulated molecules and vesicular structures participating in vesicular trafficking-related events with a pivotal role of EhVps23.

Adipose tissue: colors, depots and functions

Obesity is a chronic disease characterized by excessive accumulation of adipose tissue. The prevalence of obesity and associated diseases has prompted researchers to expand the study of the biology of adipose tissue. New technologies have significantly expanded the understanding of adipogenesis mechanisms, various aspects of lipid and glucose metabolism, as well as the paracrine and endocrine functions of adipose tissue. Adipose tissue is a complex, heterogeneous endocrine organ. The existence of several shades of adipocytes demonstrates their morphological and functional heterogeneity. The main function of white adipose tissue is to store energy. Brown and white adipocytes perform a predominantly thermogenic function. Bone marrow (yellow) adipose tissue regulates the processes of bone remodeling and hematopoiesis. Pink adipocytes are formed during pregnancy and satisfy the energy needs of the offspring. The study of the biology of adipose tissue is crucial to understanding the pathophysiology of obesity and determining its molecular relationships with type 2 diabetes as well as cardiovascular and oncological diseases. The review presents current literature data on the origin, adipogenesis, and functional properties of adipose tissue depending on its cellular composition and localization. It outlines the nature of changes in adipose tissue in obesity and the clinical significance and therapeutic potential of various adipose tissue depots.

Long Non-Coding RNA SNHG12 Contributes to Cisplatin Resistance by Mediating WEE1 via miR-503-5p in Cervical Cancer

Background: Emerging evidences have indicated that the aberrant expression of long noncoding RNAs (lncRNAs) was responsible for drug resistance, which represents a major obstacle for chemotherapy failure. Our previous study has showed that small nuclear RNA host gene 12 (SNHG12) was increased and contributed to cell growth and invasion in cervical cancer. In the present study, we aimed to investigate the role of the lncRNA SNHG12 in cisplatin (DDP) resistance and elucidate its underlying mechanisms in cervical cancer.Methods: The expression and prognosis of SNHG12 in cervical cancer tissues were evaluated based on bioinformatics. MTT, colony formation assay and flow cytometer were performed to detect cell viability. Further, Molecular relationships among CTD-3252C9.4, IRF1 and IFI6 were investigated via luciferase reporter assay, western blot, and qRT-PCR. Finally, subcutaneous xenograft model was established to verify our findings.Results: In the present study, we evaluated the cell apoptosis and half maximal inhibitory concentration (IC50) of cervical cancer upon DDP treatment. Mechanically, we found that SNHG12 upregulated WEE1 expression to regulate cell and DDP resistance via sponging miR-503-5p. Moreover, SNHG12 silencing inhibited the growth of DDP-resistant cervical cancer tumors in vivo. Conclusions: Taken together, our findings suggested that a SNHG12/miR-503-5p/ WEE1 axis which modulated the chemoresistance of cervical cancer cell to DDP, and provided promising targets for dealing with the chemoresistance of cervical cancer.

As potential biomarkers, kinetic network features may be more predictive than molecule abundances

The identification of prognostic biomarkers fuels personalized medicine. Here we tested two underlying, but often overlooked assumptions: 1) measurements at the steady state are sufficient for predicting the response to drug action, and 2) specifically, measurements of molecule abundances are sufficient. It is not clear that these are justified, as 1) the response results from non-linear molecular relationships, and 2) the steady state is defined by both abundance and orthogonal flux information. An experimentally validated mathematical model of the cellular response to the anti-cancer agent TRAIL was our test case. We developed a mathematical representation in which abundances and fluxes (static and kinetic network features) are largely independent, and simulated heterogeneous drug responses. Machine learning revealed predictive power, but that kinetic, not static network features were most informative. Analytical treatment of the underlying network motif identified kinetic buffering as the relevant circuit design principle. Our work suggests that network topology considerations ought to guide biomarker discovery efforts.

Network-based pathogenicity prediction for variants of uncertain significance

While the number of genome sequences continues to increase, the functions of many detected gene variants remain to be identified. These variants of uncertain significance constitute a major barrier to precision medicine. Although many computational methods have been developed to predict the function of these variants, they all rely on individual gene features and do not consider complex molecular relationships. Here we develop PathoGN, a molecular network-based approach for predicting variant pathogenicity. PathoGN significantly outperforms existing methods using benchmark datasets. Moreover, PathoGN successfully predicts the pathogenicity of 3,994 variants of uncertain significance in the real-world database ClinVar and designates potential pathogenicity. This is the first computational method for the clinical interpretation of variants using biomolecular networks, and we anticipate our method to be broadly useful for the clinical interpretation of variants and for assigning biological function to unknown variants at the genomic scale.

The Cellular Choreography of Osteoblast Angiotropism in Bone Development and Homeostasis

Interaction between endothelial cells and osteoblasts is essential for bone development and homeostasis. This process is mediated in large part by osteoblast angiotropism, the migration of osteoblasts alongside blood vessels, which is crucial for the homing of osteoblasts to sites of bone formation during embryogenesis and in mature bones during remodeling and repair. Specialized bone endothelial cells that form “type H” capillaries have emerged as key interaction partners of osteoblasts, regulating osteoblast differentiation and maturation and ensuring their migration towards newly forming trabecular bone areas. Recent revolutions in high-resolution imaging methodologies for bone as well as single cell and RNA sequencing technologies have enabled the identification of some of the signaling pathways and molecular interactions that underpin this regulatory relationship. Similarly, the intercellular cross talk between endothelial cells and entombed osteocytes that is essential for bone formation, repair, and maintenance are beginning to be uncovered. This is a relatively new area of research that has, until recently, been hampered by a lack of appropriate analysis tools. Now that these tools are available, greater understanding of the molecular relationships between these key cell types is expected to facilitate identification of new drug targets for diseases of bone formation and remodeling.

Retinoschisis and Norrie disease: a missing link

Objective Retinoschisis and Norrie disease are X-linked recessive retinal disorders caused by mutations in RS1 and NDP genes respectively. Both are likely to be monogenic and no locus heterogeneity has been reported. However, there are reports showing overlapping features of Norrie disease and retinoschisis in a NDP knock-out mouse model and also the involvement of both the genes in retinoschisis patients. Yet, the exact molecular relationships between the two disorders have still not been understood. The study investigated the association between retinoschisin (RS1) and norrin (NDP) using in vitro and in silico approaches. Specific protein–protein interaction between RS1 and NDP was analyzed in human retina by co-immunoprecipitation assay and MALDI-TOF mass spectrometry. STRING database was used to explore the functional relationship. Result Co-immunoprecipitation demonstrated lack of a direct interaction between RS1 and NDP and was further substantiated by mass spectrometry. However, STRING revealed a potential indirect functional association between the two proteins. Progressively, our analyses indicate that FZD4 protein interactome via PLIN2 as well as the MAP kinase signaling pathway to be a likely link bridging the functional relationship between retinoschisis and Norrie disease.