IDH1 mutation-associated long non-coding RNA expression profile changes in glioma.

Isocitrate dehydrogenase 1 (IDH1) mutation is an important prognostic marker in glioma. However, its downstream effect remains incompletely understood. Long non-coding RNAs (lncRNAs) are emerging as important regulators of tumorigenesis in a number of human malignancies, including glioma. Here, we investigated whether and how lncRNA expression profiles would differ between gliomas with or without IDH1 mutation. By using our previously reported lncRNA mining approach, we performed lncRNA profiling in three public glioma microarray datasets. The differential lncRNA expression analysis was then conducted between mutant-type and wild-type IDH1 glioma samples. Comparison analysis identified 14 and 9 lncRNA probe sets that showed significantly altered expressions in astrocytic and oligodendroglial tumors, respectively (fold change ≥ 1.5, false discovery rate ≤ 0.1). Moreover, the differential expressions of these lncRNAs could be confirmed in the independent testing sets. Functional exploration of the lncRNAs by analyzing the lncRNA-protein interactions revealed that these IDH1 mutation-associated lncRNAs were involved in multiple tumor-associated cellular processes, including metabolism, cell growth and apoptosis. Our data suggest the potential roles of lncRNA in gliomagenesis, and may help to understand the pathogenesis of gliomas associated with IDH1 mutation.

Comparison between self-assembling peptide nanofiber scaffold (SAPNS) and fibrin sealant in neurosurgical hemostasis.

RADA16-I is a synthetic type I self-assembling peptide nanofiber scaffold (SAPNS) which may serve as a novel biocompatible hemostatic agent. Its application in neurosurgical hemostasis, however, has not been explored. Although RADA16-I is nontoxic and nonimmunogenic, its intrinsic acidity may potentially provoke inflammation in the surgically injured brain. We conducted an animal study to compare RADA16-I with fibrin sealant, a commonly used agent, with the hypothesis that the former would be a comparable alternative. Using a standardized surgical brain injury model, 30 Sprague-Dawley rats were randomized into three treatment groups: RADA16-I, fibrin sealant or gelatin sponge (control). Animals were sacrificed on day 3 and 42. Astrocytic and microglial infiltrations within the cerebral parenchyma adjacent to the operative site were significantly lower in the RADA16-I and fibrin sealant groups than control. RADA16-I did not cause more cellular inflammatory response despite its acidity when compared with fibrin sealant. Immunohistochemical studies showed infiltration by astrocytes and microglia into the fibrin sealant and RADA16-I grafts, suggesting their potential uses as tissue scaffolds. RADA16-I is a promising candidate for further translational and clinical studies that focus on its applications as a safe and effective hemostat, proregenerative nanofiber scaffold as well as drug and cell carrier.

Dendrimer encapsulation enhances anti-inflammatory efficacy of silver nanoparticles.

BACKGROUND: Our previous studies revealed that silver nanoparticles (AgNPs) promoted wound healing in part through their anti-inflammatory actions. As recent reports also suggested anti-inflammatory effects of dendrimers, we therefore undertook this study using dendrimer as the delivery system for AgNP to explore any potential synergistic anti-inflammatory efficacy. METHODS: Lipopolysaccharide (LPS) was added to cultured RAW264.7 and J774.1 cells to mimic in vitro inflammation condition, followed by the addition of either silver dendrimer nanocomposite (Ag-DNC), AgNPs, or dendrimer. The levels of inflammatory markers TNF-alpha and interleukin-6 were assessed using ELISA assay. Furthermore, in vivo effects such of Ag-DNC, AgNPs, or dendrimer were studied in a burn wound model in mice. RESULTS: Our results confirmed that both naked dendrimer and AgNPs had anti-inflammatory properties. In in vitro study, Ag-DNC was shown to have the best anti-inflammatory efficacy than AgNPs or dendrimer alone. In-vivo experiments also indicated that animals in the Ag-DNC group had the fastest healing time with the least inflammation. CONCLUSION: Our study would suggest that dendrimer could provide additional anti-inflammatory benefits and might be an excellent delivery system for silver nanoparticles for future clinical application.

Systemic progesterone for modulating electrocautery-induced secondary brain injury.

Bipolar electrocautery is an effective and commonly used haemostatic technique but it may also cause iatrogenic brain trauma due to thermal injury and secondary inflammatory reactions. Progesterone has anti-inflammatory and neuroprotective actions in traumatic brain injury. However, its potential use in preventing iatrogenic brain trauma has not been explored. We conducted a pilot animal study to investigate the effect of systemic progesterone on brain cellular responses to electrocautery-induced injury. Adult male Sprague-Dawley rats received standardized bipolar electrocautery (40 W for 2 seconds) over the right cerebral cortex. The treatment group received progesterone intraperitoneally 2 hours prior to surgery; the control group received the drug vehicle only. Immunohistochemical studies showed that progesterone could significantly reduce astrocytic hypertrophy on postoperative day 1, 3 and 7, as well as macrophage infiltration on day 3. The number of astrocytes, however, was unaffected. Our findings suggest that progesterone should be further explored as a neuroprotective agent against electrocautery-induced or other forms of iatrogenic trauma during routine neurosurgical procedures. Future studies may focus on different dosing regimens, neuronal survival, functional outcome, and to compare progesterone with other agents such as dexamethasone.

Peptide nanofiber scaffold for brain tissue reconstruction.

Traumatic brain injury (TBI) and neurosurgical procedures commonly result in tissue loss within the cerebral parenchyma. Regeneration is limited by the anatomical tissue gaps and the hostile microenvironment created by the trauma. A search for novel biomaterials that are neuroprotective and conducive to healing and regeneration is needed. One approach is with the use of RADA16-I, a type I self-assembling peptide nanofiber scaffold. We review the current evidence on the use of RADA16-I and describe our experience with its use in rodent models of surgical brain injury. A cortical resection model is used to mimic the significant amount of tissue loss seen in TBI and clinical surgery. The use of RADA16-I as a carrier of transplantable neuroprogenitor cells and a potential topical hemostatic agent is described. RADA16-I can bridge tissue gaps and reduce surrounding reactive changes. Embedment of transplantable cells within the tissue scaffold is feasible. RADA16-I achieves hemostasis almost instantaneously and is associated with less tissue damage when compared with other conventional methods. There are, however, certain limitations with the application of RADA16-I mainly due to its intrinsically low pH and need for prebuffering. The use of peptide nanofiber scaffold is a promising approach for the reconstruction of the injured brain. New experimental models and research methods are required to fully explore its potential in minimizing secondary brain injuries and to promote neuronal regeneration.

[Rapid differentiation of human umbilical cord-derived mesenchymal stem cells into insulin-secreting cells under the sole induction of biological products].

In order to explore the feasibility of inducing the human umbilical cord-derived mesenchymal stem cells (hUC-MSCs) to differentiate into insulin-secreting cells with biological products alone, hUC-MSCs were separated and purified from the whole umbilical cord by the sequent digestion of collagenase II and trypsin followed by two-step centrifugation. hUC-MSCs were induced with IMDM culture medium containing epidermal growth factor (EGF), basic fibroblast growth factor (bFGF) and Ginkgo biloba extract (GBE). Before and after the induction, the morphological changes were observed under inverse microscope; the islet-related genes were detected by RT-PCR; islet-like clusters (ILCs) were identified by dithizone (DTZ) staining; PDX-1 and immunoreactive insulin (IRI) were examined by immunofluorescence method; the quantity and quality of IRI secretion were assayed by chemiluminescence immunoassay and Western blot respectively. The results showed that the purified hUC-MSCs presented long spindle-like shape and parallel or spiral arrangement which are typical morphological features of MSCs. After the induction, hUC-MSCs changed gradually into round or oval shape and gathered together to form ILCs; there were more than one hundred clusters on the growth surface of a flask of T25; ILCs were stained into positive mauve by DTZ and positive for PDX-1 and IRI; Western blot displayed that most of the IRI was proinsulin (PI). Therefore, hUC-MSCs can rapidly differentiate into insulin-secreting cells under the sole induction of EGF, bFGF, GBE and IMDM, but ILCs are not mature enough to produce sufficient true insulin.

[Proliferative capacity of mesenchymal stem cells from human fetal bone marrow and their ability to differentiate into the derivative cell types of three embryonic germ layers].

Strong proliferative capacity and the ability to differentiate into the derivative cell types of three embryonic germ layers are the two important characteristics of embryonic stem cells. To study whether the mesenchymal stem cells from human fetal bone marrow (hfBM-MSCs) possess these embryonic stem cell-like biological characteristics, hfBM-MSCs were isolated from bone barrows and further purified according to the different adherence of different kinds of cells to the wall of culture flask. The cell cycle of hfBM-MSCs and MSC-specific surface markers such as CD29, CD44, etc were identified using flow cytometry. The expressions of human telomerase reverse transcriptase (hTERT), the embryonic stem cell-specific antigens, such as Oct4 and SSEA-4 were detected with immunocytochemistry at the protein level and were also tested by RT-PCR at the mRNA level. Then, hfBM-MSCs were induced to differentiate toward neuron cells, adipose cells, and islet B cells under certain conditions. It was found that 92.3% passage-4 hfBM-MSCs and 96.1% passage-5 hfBM-MSCs were at G(0)/G(1) phase respectively. hfBM-MSCs expressed CD44, CD106 and adhesion molecule CD29, but not antigens of hematopoietic cells CD34 and CD45, and almost not antigens related to graft-versus-host disease (GVHD), such as HLA-DR, CD40 and CD80. hfBM-MSCs expressed the embryonic stem cell-specific antigens such as Oct4, SSEA-4, and also hTERT. Exposure of these cells to various inductive agents resulted in morphological changes towards neuron-like cells, adipose-like cells, and islet B-like cells and they were tested to be positive for related characteristic markers. These results suggest that there are plenty of MSCs in human fetal bone marrow, and hfBM-MSCs possess the embryonic stem cell-like biological characteristics, moreover, they have a lower immunogenic nature. Thus, hfBM-MSCs provide an ideal source for tissue engineering and cellular therapeutics.

[Effects of fimbria/fornix transection on rat's synaptic configuration of hippocampus CA3 area].

AIM: To observe the effect of fimbria-fornix (FF) transection on rat's hippocampal synaptic configuration. METHODS: Animal models were produced by transecting rat's bilateral fimbria-fornix (FF). Y-type maze test were carried out respectively before and after the models were built, and emphasis was laid on the quantitative analyses of the parameters of synapses in the hippocampal CA3 areas. RESULTS: The thickness of postsynaptic density material, the curvature of synaptic interface and the occurrence of perforated synapses decreased, while the width of synaptic cleft increased. CONCLUSION: Fimbria-fornix transection resulted in evident changes of the synaptic configuration in the hippocampal CA3 areas and we presume that the normal Ach level in the hippocampus plays a key role in maintaining the normal synaptic interface ultrastructure of the hippocampus CA3 area.