Resolving the lineage relationship between malignant cells and vascular cells in glioblastomas

Glioblastoma multiforme (GBM), a highly malignant and heterogeneous brain tumor, contains various types of tumor and non-tumor cells. Whether GBM cells can trans-differentiate into non-neural cell types, including mural cells or endothelial cells (ECs), to support tumor growth and invasion remains controversial. Here we generated two genetic GBM models de novo in immunocompetent mouse brains, mimicking essential pathological and molecular features of human GBMs. Lineage-tracing and transplantation studies demonstrated that, although blood vessels in GBM brains underwent drastic remodeling, evidence of trans-differentiation of GBM cells into vascular cells was barely detected. Intriguingly, GBM cells could promiscuously express markers for mural cells during gliomagenesis. Furthermore, single-cell RNA sequencing showed that patterns of copy number variations (CNVs) of mural cells and ECs were distinct from those of GBM cells, indicating discrete origins of GBM cells and vascular components. Importantly, single-cell CNV analysis of human GBM specimens also suggested that GBM cells and vascular cells are likely separate lineages. Rather than expansion owing to trans-differentiation, vascular cell expanded by proliferation during tumorigenesis. Therefore, cross-lineage trans-differentiation of GBM cells is very unlikely to occur during gliomagenesis. Our findings advance understanding of cell lineage dynamics during gliomagenesis, and have implications for targeted treatment of GBMs.

Vascular Calcification in Patients with Chronic Kidney Disease / 대한내과학회지

Cardiovascular morbidity and mortality are very common in patients with chronic kidney disease, which may result in part from vascular calcification. Vascular calcification requires osteoblastic trans-differentiation of vascular smooth muscle cells through an active and highly regulated process that is morphologically and functionally similar to bone formation in a number of ways. Multiple studies have been published on this topic, but the precise mechanism of vascular calcification remains unclear. This review presents recent insights into the mechanism of vascular calcification, as well as therapies that modulate mineral metabolism.

Analysis on differentially expressed microRNAs for TGF-β1-induced trans-differentiation in MRC-5 cells / 中国职业医学

OBJECTIVE: To investigate the differentially expressed microRNAs(miRNAs) in human embryonic lung fibroblast MRC-5 cells stimulated by transforming growth factor-β1(TGF-β1) using microarray chip, and screen for key genes and signaling pathways of fibroblast trans-differentiation. METHODS: The miRNA expression gene chip dataset GSE43992 on TGF-β1 stimulated MRC-5 cells were downloaded from high-throughput Gene Expression Omnibus(GEO) database of National Center for Biotechnology Information of the United States. The R language Limma package was used to screen the differentially expressed miRNAs. Corresponding target genes were predicted by miRWalk database performed by Gene Ontology(GO) functional enrichment analysis and Kyoto Encyclopedia of Genes and Genomes(KEGG) signaling pathway enrichment analysis. The protein-protein interaction(PPI) network was constructed by the search tool for the Retrieval of Interacting Genes database. RESULTS: A total of five differentially expressed miRNAs were identified, including four up-regulated miRNAs and one down-regulated miRNA; and 42 corresponding differentially expressed target genes were predicted. GO analysis indicated that the target genes were significantly enriched in collagen catabolic process, extracellular matrix organization, membrane organization, collagen fibril organization, and cellular response to amino acid stimulus. The results of KEGG pathway analysis showed that the signaling pathways corresponding to miRNAs and target genes were mainly concentrated in 18 signaling pathways, that were mainly related to the age-ethnic signaling pathways and protein digestion and absorption miRNAs in tumors and diabetic complications. The core genes transfected into the myofibroblasts by the three fibroblasts screened by the PPI network were threonine kinase 1, estrogen receptor 1 and β-catenin. CONCLUSION: Five differentially expressed miRNAs, 42 target genes, 18 signaling pathways, and 3 core genes related to TGF-β1-induced MRC-5 cell trans-differentiation were screened. It can provide new reference for the treatment and research of many diseases including pneumoconiosis and pulmonary fibrosis.

Expansion and phenotypic changes of mouse bone marrow mesenchymal cells cultured with FGF-2 and facial nerve-conditioned medium / Expansión y cambios fenotípicos de células mesenquimales de médula ósea de ratón cultivadas con FGF-2 y medio condicionado por el nervio facial

Mesenchymal cells (MCs) exhibit great regenerative potential due to their intrinsic properties and ability to restore tissue function, either directly through transdifferentiation or indirectly through paracrine effects. This study aimed to evaluate morphometric and phenotypic changes in MCs grown with facial nerve-conditioned medium in the presence or absence of fibroblast growth factor 2 (FGF-2). For quantitative phenotypic analysis, the expression of GFAP, OX-42, MAP-2, β-tubulin III, NeuN, and NF-200 was analyzed by immunocytochemistry. Cells cultured with facial nerve-conditioned medium in the presence of FGF-2 expressed GFAP, OX-42, MAP-2, β-tubulin III, NeuN, and NF-200. On average, the area and perimeter of GFAP-positive cells were higher in the group cultured with facial nerve-conditioned medium compared to the group cultured with conditioned medium and FGF-2 (p=0.0001). This study demonstrated the plasticity of MCs for neuronal and glial lineages and opens up new research perspectives in cell therapy and trans.differentiation.

Las células mesenquimales (CM) exhiben un gran potencial regenerativo debido a sus propiedades intrínsecas y la capacidad de restaurar la función del tejido, ya sea directamente, a través de la transdiferenciación, o indirectamente, a través de efectos parácrinos. Este estudio tuvo como objetivo evaluar los cambios morfométricos y fenotípicos en CM cultivadas con medio condicionado por nervio facial en presencia o ausencia de factor de crecimiento de fibroblastos 2 (FGF-2). Para el análisis fenotípico cuantitativo, se analizó la expresión de GFAP, OX-42, MAP-2, β-tubulina III, NeuN y NF-200 mediante inmunocitoquímica. Las células cultivadas con medio condicionado por el nervio facial en presencia de FGF-2 expresaban GFAP, OX-42, MAP-2, β-tubulina III, NeuN y NF-200. En promedio, el área y el perímetro de las células positivas para GFAP fueron mayores en el grupo cultivado con medio condicionado por el nervio facial en comparación con el grupo cultivado con medio acondicionado y FGF-2 (p = 0,0001). Este estudio demostró la plasticidad de CM para linajes neuronales y gliales y abre nuevas perspectivas de investigación en terapia celular y transdiferenciación.

Concomitant follicular lymphoma and histiocytic sarcoma: A rare progression, trans-differentiation or co-occurrence.

Trans‑differentiation of follicular lymphoma (FL) into a histiocytic sarcoma (HS) is a rare event and usually occurs as a sequential event. We report a case where in the same node with two distinct areas one of low‑grade FL and another with HS was observed. This patient was a 58 years old with generalized lymphadenopathy and Ann Arbor Stage III disease. The cervical node biopsy on histological examination revealed two distinct areas, firstly a FL with nodular architecture and the other a smaller focus of sheets of pleomorphic histiocytic cells diffusely arranged at the edge of the section contiguous with FL with few cells in transiting phase. On immunohistochemistry the FL was positive for CD20, CD10, PU.1, PAX5 and Bcl2, while the large histiocytic cells were positive for CD163, CD68, LCA, and PU.1, weakly for PAX5 and negative for CD20, CD10, CD30, CD3, CD1a, Bcl2, S100, and Alk‑1. The therapeutic implications of this diagnosis and postulated theories on trans‑differentiation are discussed.

Trans-differentiation of iris pigmented epithelial cells of Euphlyctis cyanophlyctis tadpoles into lens in vitro.

Meshed pigmented iris epithelium along with neural retina of tadpoles of the frog Euphlyctis cyanophlyctis were found to undergo dedifferentiation and subsequently transdifferentiate into lens in culture medium. During lag period, depigmentation (dedifferentiation) occurred in many cells. When culture became confluent 3-4 weeks after seeding tiny lens like structures differentiated from foci of cultured pigmented iris epithelium cells. The percentage of lens formation was higher in vitamin A treated cases. The culture system appears to be a suitable for investigating the changes occurred during trans-differentiation of pigmented epithelial cells into lens.

Overexpression of PTEN Inhibits Renal Epithelial-mesenchymal Trans-differentiation Induced by TGF-β1 / 华中科技大学学报(医学版)

Objective To investigate the inhibitory effects of overexpression of PTEN on renal epithelial-mesenchymal trans-differentiation induced by TGF-β1,and the signaling transduction mechanism.Methods HKC cells were transfected with GFP-PTEN via lipofectAMINE2000.The efficiency of transfection was detected by fluorescence microscope.The expression of PTEN protein and mRNA in the translected cells was detected by Western blot and RT-PCR respectively.The experiment was divided into four groups:normal group,TGF-β1 stimulation group,GFP-PTEN+TGF-β1 group and empty vector+TGF-β1 group.The expression of E-cadherin,a-SMA,Akt and p-Akt was detected by Western blot.Results Most ceils transfected with GFP-PTEN expressed GFP.The expression of PTEN protein and mRNA was strongly increased when HKC cells were transfected with GFP-PTEN(all P<0.05).In both TGF-β1 stimulation group and empty vector+TGF-β1 group,the expression level of E-cadherin was lower(all P<0.05),while that of p-Akt and a-SMA was higher than in normal group(both P<0.05).The expression level of p-Akt and a-SMA in GFP-PTEN+TGF-β1 group was Iower(both P<0.05),while that of E-cadherin was higher than in TGF-β1 stimulation group and empty vector+TGF-β1 group(both P<0.05).The expression of Akt was similar in the four groups.Conclusion Overexpression of PTEN can inhibit renal epithelial-mesenehymal trans-differentiation induced by TGF-β1 through suppressing the activation of PI3K/Akt signal pathway.

Effects of Basic Fibroblast Growth Factor on Proliferation of Human Mesenchymal Stem cells / 대한해부학회지

Human mesenchymal stem cells (hMSCs) are multipotent stem cells that can differentiate into several mesenchymal lineage cells. In this study, we established conditions that allowed a long term expansion of hMSCs. To search for the optimum culture condition, growth rates of hMSCs were measured in the presence of several growth factors. Hepatic growth factor (HGF) and leukemia inhibitory factor (LIF) did not facilitate proliferation of hMSCs. In contrast, basic fibroblast growth factor (bFGF) effectively promoted growth of the cells in vitro by 3 fold. The growth stimulatory effect of bFGF was dependent on the concentration. The adipogenic potential was dramatically decreased in hMSCs isolated from an aged donor whereas osteogenic potential was minimally decreased. Addition of bFGF resumed the adipogenic and osteogenic differentiation potential. Thus, the cells that expanded in the presence of bFGF retained the potential to differentiate into adipogenic, chondrogenic, or osteogenic lineage cells. MSCs could be expanded for at least 8 passages with bFGF and the resulting cells retained the normal karyotype. The cells were positive for CD9, CD13, CD15, CD90, CD137, and CD140b; but negative for CD14, CD34, and CD45. Importantly, the cells were found to express a neural stem cell marker, nestin, and a neuronal marker, beta-tubulin III. The results suggest that bFGF promote proliferation while maintaining multi-lineage differentiation potency of hMSCs. Finally, we suggest that it is critical to identify novel markers other than nestin or beta-tubulin III to monitor acquisition of neuronal phenotypes by hMSCs.

Effects of uremic serum on the proliferation and trans-differentiation of human renal tubular epithelial cells / 中国病理生理杂志

AIM: To explore the effects of uremic serum on proliferation and trans-differentiation of human renal tubular epithelial cells. METHODS: Human renal tubular epithelial cell line (HK-2) was cultured in RPMI-1640 medium. The proliferation effects of uremic serum at different concentrations were evaluated by methylene blue assay (MTT method) and flow cytometry. The positive cells percentage of ?-smooth muscle actin(?-SMA)in different concentration uremic serum medium was also measured by flow cytometry in vitro. RESULTS: Absorbance 490 (A 490) was increased in 5%-20% uremic serum groups compared with that in normal controls with the use of MTT. Cells in G 1 phase were decreased, but proliferation index (PI) was increased in 10%-20% uremic serum groups compared with that in normal controls with the use of flow cytometry. No significant difference of cell proliferation index was found among uremic serum groups. The positive percentage of ?-SMA cells was increased significantly in uremic serum groups compared with that in normal controls, and increased in parallel with the increasing of uremic serum concentration. CONCLUSION: Uremic toxin may accelerate renal tubulointerstitial fibrosis through promoting renal tubular epithelial cell proliferation and trans-differentiation in patients with chronic renal failure.