Disruption of mitochondrial energy metabolism is a putative pathogenesis of Diamond-Blackfan anemia.

Energy metabolism in the context of erythropoiesis and related diseases remains largely unexplored. Here, we developed a primary cell model by differentiating hematopoietic stem progenitor cells toward the erythroid lineage and suppressing the mitochondrial oxidative phosphorylation (OXPHOS) pathway. OXPHOS suppression led to differentiation failure of erythroid progenitors and defects in ribosome biogenesis. Ran GTPase-activating protein 1 (RanGAP1) was identified as a target of mitochondrial OXPHOS for ribosomal defects during erythropoiesis. Overexpression of RanGAP1 largely alleviated erythroid defects resulting from OXPHOS suppression. Coenzyme Q10, an activator of OXPHOS, largely rescued erythroid defects and increased RanGAP1 expression. Patients with Diamond-Blackfan anemia (DBA) exhibited OXPHOS suppression and a concomitant suppression of ribosome biogenesis. RNA-seq analysis implied that the substantial mutation (approximately 10%) in OXPHOS genes accounts for OXPHOS suppression in these patients. Conclusively, OXPHOS disruption and the associated disruptive mitochondrial energy metabolism are linked to the pathogenesis of DBA.

Platform-independent approach for cancer detection from gene expression profiles of peripheral blood cells.

Peripheral blood gene expression intensity-based methods for distinguishing healthy individuals from cancer patients are limited by sensitivity to batch effects and data normalization and variability between expression profiling assays. To improve the robustness and precision of blood gene expression-based tumour detection, it is necessary to perform molecular diagnostic tests using a more stable approach. Taking breast cancer as an example, we propose a machine learning-based framework that distinguishes breast cancer patients from healthy subjects by pairwise rank transformation of gene expression intensity in each sample. We showed the diagnostic potential of the method by performing RNA-seq for 37 peripheral blood samples from breast cancer patients and by collecting RNA-seq data from healthy donors in Genotype-Tissue Expression project and microarray mRNA expression datasets in Gene Expression Omnibus. The framework was insensitive to experimental batch effects and data normalization, and it can be simultaneously applied to new sample prediction.

eRF3b-37 inhibits the TGF-ß1-induced activation of hepatic stellate cells by regulating cell proliferation, G0/G1 arrest, apoptosis and migration.

The therapeutic management of liver fibrosis remains an unresolved clinical problem. The activation of hepatic stellate cells (HSCs) serves a pivotal role in the formation of liver fibrosis. In our previous study, matrix­assisted laser desorption/ionization time­of­flight mass spectrometry (MALDI­TOF MS) was employed to identify potential serum markers for liver cirrhosis, such as eukaryotic peptide chain releasing factor 3b polypeptide (eRF3b­37), which was initially confirmed by our group to serve a protective role in liver tissues in a C­C motif chemokine ligand 4­induced liver cirrhosis mouse model. Therefore, eRF3b­37 was hypothesized to affect the activation state of HSCs, which was determined by the expression of pro­fibrogenic associated factors in HSCs. In the present study, peptide synthesis technology was employed to elucidate the role of eRF3b­37 in the expression of pro­fibrogenic factors induced by transforming growth factor­ß1 (TGF­ß1) in LX­2 cells that were treated with either control, TGF­ß1 and TGF­ß1+eRF3b­37. 3­(4,5­Dimethyl­2­thiazolyl)­2,5­diphenyltetrazolium bromide and flow cytometric assays, and fluorescent microscope examinations were performed to evaluate the effects of eRF3b­37 on proliferation viability, G0/G1 arrest, apoptosis and cell migration. The results of the present study indicated that eRF3b­37 inhibited the activation of HSCs. The increased mRNA and protein expression of the pro­fibrogenic factors collagen I, connective tissue growth factor and α­smooth muscle actin (SMA) stimulated by TGF­ß1 were reduced by eRF3b­37 via the following mechanisms: i) Inhibiting LX­2 cell proliferation, leading to G0/G1 cell cycle arrest and inhibition of DNA synthesis by downregulating the mRNA expressions of Cyclin D1 and cyclin dependent kinase­4, and upregulating the levels of P21; ii) increasing cell apoptosis by upregulating the mRNA level of B­cell lymphoma-2 (Bcl­2)­associated X protein (Bax) and Fas, and downregulating the expression of Bcl­2; and iii) reducing cell migration by downregulating the mRNA and protein expression of α­SMA. In addition, eRF3b­37 is thought to serve a role in HSCs by inhibiting TGF­ß signaling. Therefore, eRF3b­37 may be a novel therapeutic agent for targeting HSCs for hepatic fibrosis.