Cancer stem cells are critical for cancer initiation, development, and treatment resistance. Our understanding of these processes, and how they relate to glioblastoma heterogeneity, is limited. To ...overcome these limitations, we performed single-cell RNA sequencing on 53586 adult glioblastoma cells and 22637 normal human fetal brain cells, and compared the lineage hierarchy of the developing human brain to the transcriptome of cancer cells. We find a conserved neural tri-lineage cancer hierarchy centered around glial progenitor-like cells. We also find that this progenitor population contains the majority of the cancer's cycling cells, and, using RNA velocity, is often the originator of the other cell types. Finally, we show that this hierarchal map can be used to identify therapeutic targets specific to progenitor cancer stem cells. Our analyses show that normal brain development reconciles glioblastoma development, suggests a possible origin for glioblastoma hierarchy, and helps to identify cancer stem cell-specific targets.
Caveolae/Raft-Dependent Endocytosis Nabi, Ivan R.; Le, Phuong U.
The Journal of cell biology,
05/2003, Letnik:
161, Številka:
4
Journal Article
Recenzirano
Odprti dostop
Although caveolae are well-characterized subdomains of glycolipid rafts, their distinctive morphology and association with caveolins has led to their internalization being considered different from ...that of rafts. In this review, we propose that caveolae and rafts are internalized via a common pathway, caveolae/raft-dependent endocytosis, defined by its clathrin independence, dynamin dependence, and sensitivity to cholesterol depletion. The regulatory role of caveolin-1 and ligand sorting in this complex endocytic pathway are specifically addressed.
Glioblastoma stem cells (GSCs) are invasive, treatment-resistant brain cancer cells that express downregulated in renal cell carcinoma (DRR), also called FAM107A, a genetic driver of GSC invasion. We ...developed antibody-antisense oligonucleotide (AON) conjugates to target and reduce DRR/FAM107A expression. Specifically, we used antibodies against antigens expressed on the GSCs, such as CD44 and EphA2, conjugated to chemically modified AONs against DRR/FAM107A, which were designed as chimeras of DNA and 2′-deoxy-2′-fluoro-beta-D-arabinonucleic acid (FANA) for increased nuclease stability and mRNA affinity. We demonstrate that these therapeutic conjugates successfully internalize, accumulate, and reduce DRR/FAM107A expression in patient-derived GSCs. This is the first example of an antibody-antisense strategy against cancer stem cells.
Based on the potential involvement of Toll-like receptor (TLR) signalling in the pathogenesis of neonatal lupus (NL), it was hypothesised that fetal exposure to hydroxychloroquine (HCQ), a TLR ...inhibitor, might reduce the risk of anti-SSA/Ro/SSB/La antibody-associated cardiac manifestations of NL (cardiac-NL).
Cardiac-NL children (N=50) and controls (N=151) were drawn from the following overlapping pregnancy studies: Research Registry for NL; PR Interval and Dexamethasone Evaluation in Cardiac-NL; and Predictors of Pregnancy Outcomes: Biomarkers in Antiphospholipid Syndrome and Systemic Lupus Erythematosus (SLE). Pregnancies met the following inclusion criteria: documentation of maternal anti-SSA/Ro/SSB/La antibodies at pregnancy, confirmation of medication use and child's outcome, a diagnosis of SLE before pregnancy and birth by 31 December 2007.
Seven (14%) of the cardiac-NL children were exposed to HCQ compared with 56 (37%) of the controls (p=0.002; OR 0.28; 95% CI 0.12 to 0.63). Cases and controls were similar with respect to demographic and antibody status. Multivariable analysis adjusting for birth year, maternal race/ethnicity, antibody status, non-fluorinated steroid use and prior cardiac-NL risk yielded an OR associated with HCQ use of 0.46 (95% CI 0.18 to 1.18; p=0.10).
This case-control study suggests that, in mothers with SLE with anti-SSA/Ro/SSB/La antibodies, exposure to HCQ during pregnancy may decrease the risk of fetal development of cardiac-NL. Prospective studies are needed for confirmation.
The existence of neural stem cells (NSCs) in adult human brain neurogenic regions remains unresolved. To address this, we created a cell atlas of the adult human subventricular zone (SVZ) derived ...from fresh neurosurgical samples using single-cell transcriptomics. We discovered 2 adult radial glia (RG)-like populations, aRG1 and aRG2. aRG1 shared features with fetal early RG (eRG) and aRG2 were transcriptomically similar to fetal outer RG (oRG). We also captured early neuronal and oligodendrocytic NSC states. We found that the biological programs driven by their transcriptomes support their roles as early lineage NSCs. Finally, we show that these NSCs have the potential to transition between states and along lineage trajectories. These data reveal that multipotent NSCs reside in the adult human SVZ.
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•We created a single-cell atlas of the adult human SVZ derived from fresh samples•We discovered 2 adult radial glia cell types similar to fetal outer radial glia•We also captured early neuronal and oligodendrocytic neural stem cell states•We show NSCs can transition between states and along lineage trajectories
Molecular biology; Cell biology; Omics; Transcriptomics
Internalization of autocrine motility factor (AMF) into the endoplasmic reticulum is sensitive to the cholesterol-extracting reagent methyl-beta-cyclodextrin, inhibited by the dynamin-1 K44A mutant ...and negatively regulated by caveolin-1. Thus, AMF internalization requires a caveolae-mediated endocytic pathway. Similarly, we show here that endocytosis of cholera toxin (CTX) in NIH-3T3 fibroblasts is inhibited by adenoviral expression of the dynamin-1 K44A mutant but only partially by expression of the clathrin hub. Treatment with methyl-beta-cyclodextrin and overexpression of caveolin-1, but not the clathrin hub, selectively diminishes CTX endocytosis to the Golgi apparatus but not to endosomes. CTX is therefore targeted via a caveolin-1-regulated caveolae-mediated pathway to the Golgi. Disruption of Golgi-, caveosome- or endosome-mediated trafficking with brefeldin A, nocodazole or a 20 degrees C temperature block, respectively, inhibit CTX endocytosis to the Golgi but do not affect AMF delivery to the endoplasmic reticulum. Following an incubation of only five minutes in the presence of the clathrin hub, AMF and CTX are not cointernalized, and AMF is delivered to the AMF-R-positive smooth ER. The internalization of both ligands is nevertheless sensitive to the tyrosine kinase inhibitor genistein, confirming that they are both internalized via caveolae/raft pathways. Two distinct caveolae-mediated endocytic pathways therefore exist, including a novel direct pathway to the ER from the plasma membrane.
Caveolae are flask-shaped invaginations at the plasma membrane that constitute a subclass of detergent-resistant membrane domains enriched in cholesterol and sphingolipids and that express caveolin, ...a caveolar coat protein. Autocrine motility factor receptor (AMF-R) is stably localized to caveolae, and the cholesterol extracting reagent, methyl-β-cyclodextrin, inhibits its internalization to the endoplasmic reticulum implicating caveolae in this distinct receptor-mediated endocytic pathway. Curiously, the rate of methyl-β-cyclodextrin-sensitive endocytosis of AMF-R to the endoplasmic reticulum is increased in ras- andabl-transformed NIH-3T3 cells that express significantly reduced levels of caveolin and few caveolae. Overexpression of the dynamin K44A dominant negative mutant via an adenovirus expression system induces caveolar invaginations sensitive to methyl-β-cyclodextrin extraction in the transformed cells without increasing caveolin expression. Dynamin K44A expression further inhibits AMF-R-mediated endocytosis to the endoplasmic reticulum in untransformed and transformed NIH-3T3 cells. Adenoviral expression of caveolin-1 also induces caveolae in the transformed NIH-3T3 cells and reduces AMF-R-mediated endocytosis to the endoplasmic reticulum to levels observed in untransformed NIH-3T3 cells. Cholesterol-rich detergent-resistant membrane domains or glycolipid rafts therefore invaginate independently of caveolin-1 expression to form endocytosis-competent caveolar vesicles via rapid dynamin-dependent detachment from the plasma membrane. Caveolin-1 stabilizes the plasma membrane association of caveolae and thereby acts as a negative regulator of the caveolae-mediated endocytosis of AMF-R to the endoplasmic reticulum.
Pelvic Pain: An Overview Le, Phuong U; Fitzgerald, Colleen M
Physical medicine and rehabilitation clinics of North America,
08/2017, Letnik:
28, Številka:
3
Journal Article
Recenzirano
Although the cause of chronic pelvic pain (CPP) is multifactorial, a substantial number of cases have musculoskeletal and neuromuscular causes. Multiple stakeholders, including physicians with ...varying degrees of pain training ranging from primary care physicians, obstetricians, gynecologists, urologists, neurologists, gastroenterologists, psychologists, physical therapists, and physiatrists, are involved in the care of these patients. Physiatrists play a pivotal role in the treatment of patients with CPP because their training focuses on improving quality of life through a holistic approach to patient management and on the musculoskeletal and neuromuscular systems.
Cholera toxin is associated with caveolae and raft domains in various cell types and previous studies have shown that cholera toxin can be internalized by caveolae/raft-dependent endocytosis as well ...as by other pathways. We undertook the study of cholera toxin endocytosis in CaCo-2 and HeLa cells. CaCo-2 cells do not express detectable levels of caveolin and, relative to HeLa cells, also present significantly reduced expression of ganglioside GM1, the cholera toxin receptor, that remains Triton X-100 insoluble. Amongst the HeLa cell population, caveolin expression is constant, however, GM1 expression is highly variable. Cholera toxin is internalized to the Golgi apparatus via a caveolae/raft-dependent pathway sensitive to methyl-beta-cyclodextrin and genistein in high-GM1-expressing HeLa cells but not in low-GM1 HeLa cells or in CaCo-2 cells. Limited cholera toxin endocytosis to endosomes sensitive to neither methyl-beta-cyclodextrin nor genistein is also observed in all cells and corresponds to a non-caveolae/raft endocytic pathway. Increasing cell-associated GM1 by adding GM1 to the cell media of both HeLa and CaCo-2 cells selectively enhances the methyl-beta-cyclodextrin-, genistein-sensitive delivery of cholera toxin to the Golgi apparatus but not to endosomes. GM1 expression levels are therefore a selective determinant of caveolae/raft-dependent endocytosis of cholera toxin to the Golgi apparatus and variable expression of GM1 between cells can impact on the endocytosis and choice of pathway followed by cholera toxin.
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