Ghrelin alleviates traumatic brain injury-induced acute lung injury through pyroptosis/NF-κB pathway.

Acute lung injury (ALI) is one of the severe complications in patients with traumatic brain injury (TBI), contributing to the high mortality. Ghrelin has protective effects against various inflammatory diseases, but the effects of Ghrelin on TBI-induced ALI and its mechanisms remain unknown. In this study, Ghrelin administration was performed on the mice with TBI, then histological change in cortex and lung tissues, lung vascular permeability and macrophage number in bronchoalveolar lavage fluid (BALF) were examined, respectively. Simultaneously, the alterations of proinflammatory factors and pyroptosis-related proteins in lung tissues were detected. As a result, TBI-induced ALI was ameliorated after Ghrelin treatment, which was demonstrated by improved histology, reduced lung vascular permeability, and peripheral macrophage number. Furthermore, Ghrelin decreased the mRNA levels of proinflammatory factors (IL-1ß, IL-6, TNF-α and IL-18), the protein levels of pyroptosis-related proteins (NLRP3, Caspase1-P20, HMGB1 and Gasdermin D), and the phosphorylation levels of NF-κB in lung tissues. These results showed that Ghrelin attenuating TBI-induced ALI might be via ameliorating inflammasome-induced pyroptosis by blocking NF-κB signal, which are important for the prevention and treatment of TBI-induced ALI.

[Phenotype of SHG-44 glioma stem cell spheres and pathological characteristics of their xenograft tumors].

OBJECTIVE: To study the phenotype and tumorigenicity of SHG-44 glioma stem cell spheres and the pathological characteristics of their xenograft tumors. METHODS: SHG-44 glioma cells were cultured under neural stem cell medium and glioma stem cell spheres were collected. Immunocytochemistry was used to dectet the expression of CD133, nestin, A2B5, vimentin, VEGFR-2 and IDH R132H. Cell spheres were induced using serum-containing medium, and the expression of CD133, nestin, vimentin, GFAP, ß-III tubulin and GalC in the cell spheres were detected. The expression of CD133, nestin, VEGFR-2, GFAP, S-100 and CD34 in the intracranial xenograft tumor tissues was detected using immunohistochemistry. The pathological characteristics of orthotopic xenograft tumors generated from the SHG-44 glioma cells and SHG-44 glioma stem cell spheres were compared. RESULTS: SHG-44 glioma stem cell spheres were collected successfully after cultured under neural stem cell medium. The ratio of CD133(+) cells in the passage 10 SHG-44 glioma stem cell spheres was (71.63 ± 5.92)%, significantly higher than that in the SHG-44 glioma cells [(1.95 ± 1.45)%]. Immunocytochemistry showed that in the SHG-44 glioma cell spheres, the ratio of nestin(+) cells was (84.06 ± 7.58)%, vimentin(+) cells (29.11 ± 3.44)%, VEGFR 2(+) cells (64.44 ± 3.69)%, and A2B5(+) cells (14.08 ± 2.19)%. A subpopulation of cells with mutation of IDH R132H was detected harboring in the SHG-44 glioma cell spheres. After induction of differentiation with serum-containing medium, the ratio of CD133(+) cells was (1.89 ± 1.27)%, nestin(+) cells (6.67 ± 2.75)%, vimentin(+) cells (93.75 ± 2.95)%, GFAP (+) cells (91.33 ± 4.75)%, ß-III tubulin(+) cells (82.36 ± 4.02)%, and GalC(+) cells (8.92 ± 3.19)%. Immunohistochemistry showed positive expression of GFAP, S-100, VEGFR-2, and negative of CD133 and nestin in the orthotopic xenograft tumors. A very small amount of human-specific CD34 cells formed a tubular structure. Compared with the SHG-44 glioma cell-formed xenograft tumor, the SHG-44 glioma stem cell-formed xenograft tumor exhibited a higher local invasiveness. CONCLUSIONS: SHG-44 glioma cell spheres are successfully collected after cultured under neural stem cell medium. They belong to the CD133(+)A2B5(-) GSC subpopulation, highly expressing VEGFR-2, possess the ability of both self-renewal and multi-directional differentiation, and may participate in the formation of vasculogenic mimicry.

UHRF2 mRNA expression is low in malignant glioma but silencing inhibits the growth of U251 glioma cells in vitro.

UHRF2 is a member of the ubiquitin plant homeo domain RING finger family, which has been proven to be frequently up-regulated in colorectal cancer cells and play a role as an oncogene in breast cancer cells. However, the role of UHRF2 in glioma cells remains unclear. In this study, we performed real-time quantitative PCR on 32 pathologically confirmed glioma samples (grade I, 4 cases; grade II, 11 cases; grade III, 10 cases; and grade IV, 7 cases; according to the 2007 WHO classification system) and four glioma cell lines (A172, U251, U373, and U87). The expression of UHRF2 mRNA was significantly lower in the grade III and grade IV groups compared with the noncancerous brain tissue group, whereas its expression was high in A172, U251, and U373 glioma cell lines. An in vitro assay was performed to investigate the functions of UHRF2. Using a lentivirus-based RNA interference (RNAi) approach, we down-regulated UHRF2 expression in the U251 glioma cell line. This down- regulation led to the inhibition of cell proliferation, an increase in cell apoptosis, and a change of cell cycle distribution, in which S stage cells decreased and G2/M stage cells increased. Our results suggest that UHRF2 may be closely related to tumorigenesis and the development of gliomas.

A novel gene RNF138 expressed in human gliomas and its function in the glioma cell line U251.

BACKGROUND: The gliomas represent the most common primary malignant brain tumors; however, little is known about the molecular pathogenesis of these tumors. Recent research reveals that the oncogenesis and development of gliomas have a close relation to the overexpression of several oncogenes and the inactivation of tumor suppressor genes. Whether the RING finger protein, RNF138, a newly discovered protein, plays a role in glioma oncogenesis is unknown. The present study investigates the expression levels of RNF138 mRNA in glioma samples and noncancerous brain samples and its function in the human glioma cell line U251. METHODS: RT-PCR was used to ascertain the expression of RNF138 mRNA in the glioma cell lines U251, SHG44, U87, A172, and U373. The RNF138 mRNA expression levels of 35 pathological confirmed glioma samples (Grade I - 4 cases, Grade II - 13 cases, Grade III - 11 cases, and Grade IV - 7 cases) and five noncancerous brain tissue samples were analyzed by real-time quantitative PCR. By RNA interference (RNAi) with the lentivirus vector system, the expression of RNF138 was inhibited in the human astrocytomas-glioblastoma multiforme cell line U251. The effects of RNF138-knockdown on cell proliferation were assessed by Cellomics, and cell cycle and cell apoptosis were assessed by FACS. RESULTS: The RNF138 mRNA is expressed in the five glioma cell lines, and its expression level is significantly higher in glioma tissue than in noncancerous brain tissue. By down-regulation of RNF138 expression, U251 cell proliferation was inhibited and cell apoptosis increased. At the same time, S stage cells lessened and G2 stage cells increased. CONCLUSION: The RNF138 gene is highly expressed in glioma tissue and glioma cell lines. It plays an important role in glioma cell proliferation, apoptosis, and cell cycle.