Long-term protective effects of AAV9-mesencephalic astrocyte-derived neurotrophic factor gene transfer in parkinsonian rats.

Intrastriatal injection of mesencephalic astrocyte-derived neurotrophic factor (MANF) protein has been shown to provide neuroprotective and neurorestorative effects in a 6-hydroxydopamine (6-OHDA) - lesioned rat model of Parkinson's disease. Here, we used an adeno-associated virus serotype 9 (AAV9) vector to deliver the human MANF (hMANF) gene into the rat striatum 10days after a 6-OHDA lesion to examine long-term effects of hMANF on nigral dopaminergic neurons and mechanisms underlying MANF neuroprotection. Intrastriatal injection of AAV9-hMANF vectors led to a robust and widespread expression of the hMANF gene in the injected striatum up to 24weeks.

Construction and functional activity of a recombinant vector expressing rat glutamic acid decarboxylase 65.

Objective: Glutamic acid decarboxylase 2 (GAD65) is a gamma-aminobutyric acid (GABA) synthetase. This study aimed to construct a recombinant lentivirus-rGAD65 (rLV-rGAD65) vector containing the cDNA of rat GAD65 (rGAD65) and assess its functional activity in vitro and in vivo.

Methods: cDNA of rGAD65 was amplified by RT-PCR and subcloned into the LV vector, forming the rLV-GFP-rGAD65 plasmid.

Combination of hyaluronic acid hydrogel scaffold and PLGA microspheres for supporting survival of neural stem cells.

Purpose: To develop a biomaterial composite for promoting proliferation and migration of neural stem cells (NSCs), as well as angiogenesis on the materials, to rescue central nervous system (CNS) injuries.

Methods: A delivery system was constructed based on cross-linked hyaluronic acid (HA) hydrogels, containing embedded BDNF and VEGF-loaded poly(lactic-co-glycolic acid) (PLGA) microspheres for controlled delivery and support for NSCs in the CNS. The surface morphologies were evaluated by SEM and AFM, mechanical property was investigated by rheological tests, and release kinetics were performed by ELISA.

Hyaluronic acid hydrogel modified with nogo-66 receptor antibody and poly-L-lysine to promote axon regrowth after spinal cord injury.

The biomaterials used for central nervous system injury require not only interacting with specific cell adhesion but also specific growth factor receptors to promote nerve regeneration. In this study, hyaluronic acid (HA)-based hydrogels modified with poly-L-lysine (PLL) and nogo-66 receptor antibody (antiNgR) (HA-PLL/antiNgR) were administered to rats after lateral hemisection of the spinal cord. Anti-neurofilament positive axons were found to extend into the HA-PLL/antiNgR hydrogel at 8 weeks after implantation, which shows significant difference compared with HA-PLL or blank control group.

[Bone marrow stem cell-derived astrocytes are involved in glia limitans formation in rats after brain injury].

Objective: To investigate the involvement of bone marrow stem cell-derived astrocytes (BMDSCs) in the formation of glia limitans after brain injury.

Methods: In a female SD rat model of brain injury, green fluorescence protein (GFP)-labeled BMDSCs from male SD rats were transplanted via the caudal vein 24 h after the injury. The rats were sacrificed at 2, 4 and 8 weeks after the transplantation, and immunohistochemistry for glial fibrillary acidic protein (GFAP) was performed to observe the astrocytes.

Preparation and characterization of fibroin/hyaluronic acid composite scaffold.

Hyaluronic acid (HA) was added into fibroin solution to prepare fibroin-based porous composite scaffolds. HA exhibited important effects on pore formation and hydrophilicity of fibroin-based scaffold. The aqueous-fibroin/HA scaffolds had highly homogeneous and interconnected pores with porosity of above 90% and controllable pore size ranging from 123 to 253 microm.

An experimental test of stroke recovery by implanting a hyaluronic acid hydrogel carrying a Nogo receptor antibody in a rat model.

The objective of the study was to determine the effects of a hyaluronic-acid-based (HA-based) hydrogel implant, carrying a polyclonal antibody to the Nogo-66 receptor (NgR), on adult rats that underwent middle cerebral artery occlusion (MCAO). Behavioral tests of a forelimb-reaching task suggested that the disabled function of the impaired forelimb in this stroke model was ameliorated by the implant to a certain extent. These behavioral findings were correlated with immunohistochemical results of investigating the distribution of NgR antibody, neurofilaments (NF) and neuron-specific class III beta-tubulin (TuJ1) in the brain sections.

Layer-by-layer assembly of polyelectrolyte films improving cytocompatibility to neural cells.

The using of layer-by-layer assembly polyelectrolyte (PE) films has been suggested as a new versatile technique for surface modification aimed at tissue engineering and cell-based chips. In this study, we investigated the surface morphology of the hyaluronic acid (HA)-based PE films deposited on the amino-functionalized glass slides using atomic force microscopy. These thin films (bilayer number <9) were measured to have nanoscale roughness ranging from 10 to 100 nm.

Proliferation of neural precursors in the subventricular zone after chemical lesions of the nigrostriatal pathway in rat brain.

The proliferative activity of neural precursors from the subventricular zone (SVZ) was investigated after a unilateral lesion was formed in the nigrostriatal pathway in adult rats. The lesion was formed by unilateral injection of 6-hydroxydopamine (6-OHDA) into the nigrostriatal pathway, and then bromodeoxyuridine (BrdU) was injected (ip) for 4 days or 2 weeks 10 days after the lesion was formed. The rats were killed, and the brain sections were immunohistochemically stained to detect the expression of BrdU, polysialylated neural-cell-adhesion molecule (PSA-NCAM), glial fibrillary acidic protein (GFAP) and tyrosine hydroxylase (TH) in the SVZ and the striatum (STR).

The assays of activities and function of TH, AADC, and GCH1 and their potential use in ex vivo gene therapy of PD.

In the past decades, there have been numerous studies in the gene therapy for Parkinson's disease (PD), especially in delivering genes of enzymes for dopamine (DA) synthesis. Gene therapy in PD appears to be at the brink of the clinical study phase. However, there are many questions that need to be solved before this approach can be contemplated clinically, especially the question about the control of DA production because too much DA could cause toxicity.

[Gene therapy of tyrosine hydroxylase, aromatic L-amino acid decarboxylase, and GTP cyclohydrolase genes in rat model of Parkinson's disease].

Objective: To detect the expression and function of enzyme genes involved in biosynthetic pathway for dopamine in vitro and assess their effect in rat model of Parkinson's disease.

Methods: Cos7 cells were transfected with separate adeno-associated virus (AAV) expressing tyrosine hydroxylase (TH) gene, aromatic L-amino acid decarboxylase (AADC) gene and GTP cyclohydrolase I (GCH-I) gene. The expression and function of the three genes were detected by methods of immunohistochemistry, in situ hybridization and high performance liquid chromatograph and electrochemical detection (HPLC-ECD).

[Differentiation of bone marrow-derived stem cells in injured rat brain tissue].

Objective: To investigate the differentiation of bone marrow-derived stem cells (BMDSCs) migrated from blood circulation and resided in the injured brain tissue.

Methods: Brain injury model was established by iridectomy in the right cerebral cortex of female SD rats. Twenty-four hours after brain injury, the female rats received the implantation of green fluorescence protein (GFP)-labeled BMDSCs from male SD rats and were sacrificed at 2, 4 and 8 weeks after the implantation.

[A study on the relationship between polymorphism of human NAD(P)H: quinone oxidoreductase and Parkinson's disease in Chinese].

Objective: To detect the putative association between the polymorphism of human NAD(P)H: quinone oxidoreductase (NQO1) gene and Parkinson's disease(PD).

Methods: Polymerase chain reaction-denaturing high performance liquid chromatography (PCR-DHPLC) was used to detect the polymorphism of monoamine NQO1 gene cDNA 609 site(C-->T). The frequencies of alleles and genotypes in different PD groups were compared with those of the control group.

[Expression and assessment of double genes of tyrosine hydroxylase gene and aromatic L-amino acid decarboxylase gene in vitro].

The characteristic pathological changes of Parkinson s disease (PD) include a severe loss of dopamine neurons in the substantia nigra and a severe decrease in dopamine in the striatum. Since the expression of tyrosine hydroxylase (TH) and aromatic L-amino acid decarboxylase (AADC) in the biosynthetic pathway for dopamine are low, a promising approach to the gene therapy of PD is to augment the gene expression of the enzymes in the biosynthetic pathway for dopamine. In the present study, human TH and AADC genes were reconstructed into retrovirous vectors pLHCX and pLNCX(2) respectively.

[Identification of bone marrow stromal cells and expression of tyrosine hydroxylase gene in them].

The study is to establish the method of isolation and identification of bone marrow stromal cells and to investigate the ability of bone marrow stromal cells to accept and express TH gene. Cells were isolated by a density gradient (lymphocytes separation) and identified by BrdU labeling and fluorescence-activated cell sorting (FACS) technology using CD11b, CD45 and CD90 antibodies. TH and lacZ gene were transfected to rBMSCs with an adeno-associated virus vector.

[Relationship between the Fnu4HI site polymorphism of monoamine oxidase A gene and Parkinson's disease].

Objective: To study the association between the polymorphism of human monoamine oxidase type A (MAO-A) gene and Parkinson's disease(PD).

Methods: Fnu4HI restriction fragment length polymorphism(RFLP) and PCR-RFLP were used to detect the mutation of MAO-A gene. The frequencies of alleles and genotypes at the MAO-A Fnu4HI locus on the X chromosome in different PD group were compared with those of the control group.