An in vitro and in vivo study of the role of long non-coding RNA-HOST2 in the proliferation, migration, and invasion of human glioma cells.

Gliomas are the most commonly occurring primary malignant brain tumors in the central nervous system of adults. They are rarely curable and the prognosis for high grade gliomas is generally poor. Recently, long non-coding RNA (lncRNA) human ovarian cancer-specific transcript 2 (HOST2) has been reported to be expressed at high levels in human ovarian cancer, involving tumorigenesis. However, little is still known about whether and how HOST2 regulates glioma development and progression. Therefore, this study aims to investigate the role of HOST2 in human glioma cells. Reverse transcription quantitative real-time polymerase chain reaction (RT-qPCR) was used to determine the expression of lncRNA HOST2, let-7b, and PBX3 in human glioma cells. Cultured human glioma cells were treated with siRNA (si)-lncRNA HOST2, let-7b mimic, si-lncRNA HOST2 + let-7b inhibitor, and si-PBX3. Parameters including cell viability, colony formation, cell migration, and cell invasion were detected by cell counting kit-8 assay, colony formation assay, scratch test, and Transwell assay respectively to determine the effects of down-regulated HOST2 on glioma cells. Tumor formation in nude mice was evaluated by subcutaneous tumor formation experiment. Results showed that HOST2 and PBX3 were highly expressed in glioma tissue whereas let-7b was expressed at much lower levels. In response to treatment with si-lncRNA HOST2, si-PBX3, and let-7b mimic, glioma cell lines exhibited decreased cell viability, suppressed cell migration, invasion, and reduced colony formation of glioma cells. This was accompanied by an attenuated tumor formation with smaller volume and weight in nude mice, suggesting that down-regulated HOST2 could inhibit the tumorigenicity of glioma cells. Lastly, we found that lncRNA HOST2 was highly expressed in glioma tissues and its down-regulation could inhibit the growth and invasion of glioma cells. © 2018 IUBMB Life, 71(1):93-104, 2019.

Bcl-2 in suppressing neuronal apoptosis after spinal cord injury.

BACKGROUND: Apoptosis plays an important role in central neural diseases and trauma. B-cell lymphoma/Leukemia-2 (Bcl-2) can inhibit apoptosis in a wide variety of cells including neurons. In this experiment, by studying Bcl-2 over-expression transgenic (TG) mice subjected to spinal cord injury (SCI), we investigated whether Bcl-2 could reduce posttraumatic neuronal apoptosis, reduce the range of damage, and improve the behavioral functional recovery after contusive SCI. METHODS: Nine Bcl-2 TG mice and nine control mice were subjected to SCI of moderate severity at T10, with the use of weight dropping (WD) method (impact force 2.5×3.0 g/cm). At times up to 1 day, 7 days and 14 days after SCI, functional deficits were evaluated with Basso, Beattie, and Bresnahan (BBB) scales, and apoptosis of neurons was investigated by using the TUNEL method. Another three control mice only underwent lamina opening, but were not subjected to SCI, to provide blank comparison. RESULTS: The mean functional scores for the control mice (5.05 ±0.35) were lower than those for the Bcl-2 TG mice (5.45 ±0.15), although the unpaired T-test revealed no significant difference (P=0.67). On the other hand, the number of TUNEL positive neurons and integrated option density (IOD) scores for the Bcl-2 TG mice were both significantly lower than those for the control mice (P<0.05). CONCLUSIONS: This experiment suggests that overexpression of Bcl-2 may suppress neuronal apoptosis after SCI. Bcl-2 may be an important factor within the central nervous system that can relieve the damage after trauma.

Effect of therapeutic mild hypothermia on the genomics of the hippocampus after moderate traumatic brain injury in rats.

BACKGROUND: Traumatic brain injury (TBI), a major cause of morbidity and mortality, is a serious public health concern. OBJECTIVE: To evaluate the effect of mild hypothermia on gene expression in the hippocampus and to try to elucidate molecular mechanisms of hypothermic neuroprotection after TBI. METHODS: Rats were subjected to mild hypothermia (group 1: n = 3, 33 degrees C, 3H) or normothermia (group 2: n = 3; 37 degrees C, 3H) after TBI. Six genome arrays were applied to detect the gene expression profiles of ipsilateral hippocampus. Functional clustering and gene ontology analysis were then carried out. Another 20 rats were randomly assigned to 4 groups (n = 5 per group): group 3, sham-normothermia; group 4, sham-hypothermia; group 5, TBI-normothermia; and group 6, TBI-hypothermia. Real-time fluorescent quantitative reverse-transcription polymerase chain reaction was used to detect specific selected genes. RESULTS: We found that 133 transcripts in the hypothermia group were statistically different from those in the normothermia group, including 57 transcripts that were upregulated and 76 that were downregulated after TBI (P < .01). Most of these genes were involved in various pathophysiological processes, and some were critical to cell survival. Analysis showed that 9 gene ontology categories were significantly affected by hypothermia, including the most affected categories: synapse organization and biogenesis (upregulated) and regulation of inflammatory response (downregulated). The mRNA expression of Ank3, Cmbp, Nrxn3, Tgm2, and Fcgr3 was regulated by hypothermia, TBI, or a combination of TBI and hypothermia compared with the sham-normothermia group. Their mRNA expression was significantly regulated by hypothermia in TBI groups. CONCLUSION: Posttraumatic mild hypothermia has a significant effect on the gene expression profiles of the hippocampus, especially those genes belonging to the 9 gene ontology categories. Differential expression of those genes may be involved in the most fundamental molecular mechanisms of cerebral protection by mild hypothermia after TBI.

[A study on expression of hsp70 mRNA in the early stage of diffuse brain injury in rats].

OBJECTIVE: To evaluate the changes of hsp70 mRNA in neuron and glia of rat suffering early diffuse brain injury. METHODS: SD rats were used in the replication of the animal pattern of diffuse brain injury. In situ hybridization technique and image analysis technique were applied in detecting the hsp70 mRNA in the rat's cerebral cortex, thalamus and brain stem. RESULTS: The signal intensity of hsp70 mRNA could be detected in 5 minutes after brain injury; subsequently, it attained to the summit at 6 hours and declined at 12 hours after brain injury. CONCLUSION: The above data suggest that hsp70 mRNA is useful for the diagnosis of early diffuse brain injury and for distinguishing the postmortem injury from antemortem injury.

[Mitochondrial apoptotic signaling pathway in neurons following brain injury induced by hypoxia].

Impairment of neuronal mitochondria following hypoxia of brain not only result in nerve cell's energy-deprivation and dysfunction, mitochondria also play key roles in apoptosis of neurons. A central step being the release of cytochrome c (cyt c) across the outer mitochondrial membrane into the cytoplasm through opening of the mitochondrial permeability transition pore. Releasing of cytochrome c induce to downstream consequences of specific caspase activation. The antiapoptotic and proapoptotic members of the Bcl-2 family regulate mitochondrial activities relevant to apoptotic signaling by influencing the realaseing of cyt c.

[Cardiac troponin T and I: application in myocardial injury and forensic medicine].

The Cardiac Troponin T and I are highly cardiac specific biochemical markers of myocardial injury. They are very sensitive markers to detect all kinds of myocardial injury, and are able to distinguish myocardial injury and skeletal injury. Furthermore, They are independent predictor of future cardiac events. Such markers are now widely used in the clinic practice. It is prospective to use them in Forensic Medical Science.