AAV-mediated transfer of RhoA shRNA and CNTF promotes retinal ganglion cell survival and axon regeneration.

The aim of the present study was to determine whether adeno-associated viral vector (AAV) mediated transfer of ciliary neurotrophic factor (CNTF) and RhoA shRNA has additive effects on promoting the survival and axon regeneration of retinal ganglion cells (RGCs) after optic nerve crush (ONC). Silencing effects of AAV-RhoA shRNA were confirmed by examining neurite outgrowth in PC12 cells, and by quantifying RhoA expression levels with western blotting. Young adult Fischer rats received an intravitreal injection of (i) saline, (ii) AAV green fluorescent protein (GFP), (iii) AAV-CNTF, (iv) AAV-RhoA shRNA, or (v) a combination of both AAV-CNTF and AAV-RhoA shRNA.

Nogo-p4 Suppresses TrkA Signaling Induced by Low Concentrations of Nerve Growth Factor Through NgR1 in Differentiated PC12 Cells.

Background: Regeneration of injured axons in adult mammalian central nervous system (CNS) is not spontaneous. Nogo is a major inhibitory molecule contributing to axon regeneration failure. The molecular mechanisms of Nogo inhibition of axon regeneration are not completely understood.

p300 expression is induced by oxygen deficiency and protects neuron cells from damage.

Low oxygen level or oxygen deficiency (hypoxia) is a major factor causing neuronal damage in many diseases. Inducing cell adaptation to hypoxia is an effective method for neuroprotection that can be achieved by either inhibiting the death effectors or enhancing the survival factors. Transcription coactivator p300 is necessary for hypoxia-induced transcriptional activation and plays an important role in neuron survival.

Marked effect of RhoA-specific shRNA-producing plasmids on neurite growth in PC12 cells.

In order to promote neurite outgrowth, we constructed a plasmid producing RhoA-specific small hairpin RNA (shRNA) to block RhoA expression and tested its actions in PC12 cells. Our results show that the shRNA-mediated RNA interference (RNAi) successfully suppressed RhoA expression. As a consequence of RhoA knockdown, F-actin levels were significantly reduced and processes were markedly induced.

Chemotactic effect of ciliary neurotrophic factor on macrophages in retinal ganglion cell survival and axonal regeneration.

Purpose: To examine whether ciliary neurotrophic factor (CNTF) has a chemotactic effect on macrophages and whether macrophages are involved in CNTF-induced retinal ganglion cell (RGC) survival and axonal regeneration after optic nerve (ON) injury.

Methods: Adult Fischer 344 rats received an autologous peripheral nerve graft onto transected ON for injured axons to grow. CNTF was applied intravitreally.

PI3K/akt, JAK/STAT and MEK/ERK pathway inhibition protects retinal ganglion cells via different mechanisms after optic nerve injury.

Recently we unexpectedly found that PI3K/akt, JAK/STAT and MEK/ERK pathway inhibitors enhanced retinal ganglion cell (RGC) survival after optic nerve (ON) axotomy in adult rat, a phenomenon contradictory to conventional belief that these pathways are pro-survival. In this study we showed that: (i) the RGC protection was pathway inhibition-dependent; (ii) inhibition of PI3K/akt and JAK/STAT, but not MEK/ERK, activated macrophages in the eye, (iii) macrophage removal from the eye using clodronate liposomes significantly impeded PI3K/akt and JAK/STAT inhibition-induced RGC survival and axon regeneration whereas it only slightly affected MEK/ERK inhibition-dependent protection; (iv) in the absence of recruited macrophages in the eye, inhibition of PI3K/akt or JAK/STAT did not influence RGC survival; and (v) strong PI3K/akt, JAK/STAT and MEK/ERK pathway activities were located in RGCs but not macrophages after ON injury. In retinal explants, in which supply of blood-derived macrophages is absent, MEK/ERK inhibition promoted RGC survival whereas PI3K/akt or JAK/STAT inhibition had no effect on RGC viability.

[Hypoxia promotes apoptosis of germ cells in rat testes].

Objective: To explore the effects of hypobaric hypoxia on the apoptosis of germ cells in male rats.

Methods: Adult male Wistar rats were randomly divided into four groups: a control group raised at sea level; a 5 d, a 15 d and a 30 d hypoxic group raised in a hypobaric chamber simulating 5000 m altitude for 5 days, 15 days and 30 days respectively. Flow cytometry and TUNEL were used to evaluate the apoptosis of germ cells in the testis.

[Isolation and identification of differentially expressed proteins in hippocampus of mice during hypobaric hypoxic delayed preconditioning].

Aim: To explore the differentially expressed proteins between hypobaric hypoxic delayed preconditioning (HHDP) and normal mouse hippocampus.

Methods: After the animal model of HHDP was constructed, hippocampal proteins were obtained by a series of abstraction with lysis solution containing high concentration urea. As soon as isoelectric focusing and SDS-PAGE was performed.

[Effect of hypoxia on expression of iNOS mRNA in cultured rat astrocytes].

Aim: To explore the effects of hypoxia on expression of inducible nitric oxide synthase (iNOS) mRNA in cultured rat astrocytes.

Methods: Cultured rat astrocytes were randomly divided into 4 groups: glutamate group (G), hypoxic group (H), hypoxia + glutamate group (H + G) and the control (C). Cells of control group were exposed to normoxic (95% air, 5% CO2) condition, and cells of G and H + G were incubated with 100 micromol/L L-glutamate, cells of H and H + G exposed to hypoxic conditions (5% CO2, 95% N2) at 37 degrees C.