Chloroquine exerts neuroprotection following traumatic brain injury via suppression of inflammation and neuronal autophagic death.

The antimalarial drug, chloroquine (CQ), has been reported as an autophagy inhibitor in a variety of disorders, including Alzheimer's disease and brain ischemia. To the best of our knowledge, no studies to date have examined the potential for CQ to provide neuroprotection in animal models of traumatic brain injury (TBI). The aim of this study was to investigate the neuroprotective actions of CQ in TBI and to determine the mechanisms underlying this effect. Rats were immediately subjected to a diffuse cortical impact injury caused by a modified weight-drop device and divided randomly into three groups: sham-operated, CQ treatment and vehicle. The CQ treatment group was administered CQ (intraperitoneally, 3 mg/kg body weight) immediately following the induction of injury. The co-localization of neuron-specific nuclear protein (NeuN) and microtubule-associated protein 1 light chain 3 (LC3), was followed by immunofluorescent staining. The expression of LC3 and inflammatory cytokines was identified by western blot analysis. Wet-dry weight method was utilized to evaluate TBI-induced brain edema. Motor function was evaluated using the Neurological Severity Score (NSS) scale and the Morris water maze was employed to assess spatial learning ability. This study demonstrated that the administration of CQ attenuates TBI-induced cerebral edema, and the associated motor and cognitive functional deficits that occur post-injury. Following the induction of cerebral trauma, CQ treatment significantly suppressed neuronal autophagy and reduced expression levels of the inflammatory cytokines, interleukin-1ß (IL-1ß) and tumor necrosis factor-α (TNF-α), in the rat hippocampus. Our results have provided in vivo evidence that CQ may exert neuroprotective effects following TBI, in attenuating brain edema and improving neurological functioning, by reducing the damaging consequences of neuronal autophagy and cerebral inflammation.

Neuroprotective effects of brilliant blue G on the brain following traumatic brain injury in rats.

The P2X7 inhibitor, brilliant blue G (BBG), has been reported as a neuroprotective drug against a variety of disorders, including neuropathic pain and brain ischemia. Currently, no studies have examined the potential for BBG to provide neuroprotection in animal models of TBI. The aim of the present study was to investigate the neuroprotective effect of BBG on TBI and to determine the underlying mechanisms. The rats were subjected to a diffuse cortical impact injury caused by a modified weight-drop device, and then divided randomly into three groups: the sham-operated, BBG treatment and vehicle groups. In the BBG treatment group, 50 mg/kg brilliant blue G (BBG; 100% pure), a highly specific and clinically useful P2X7 antagonist, was administered via the tail vein 15 min prior to or up to 8 h following TBI. The co-localization of NeuN and protein kinase Cγ (PKCγ) was followed with immunofluorescent staining. The expression of P2X7, PKCγ and inflammatory cytokines was identified by western blot analysis. Wet-dry weight method was used to evaluate brain edema, and motor function outcome was examined using the neurological severity score. The present study demonstrated that the administration of BBG attenuated TBI-induced cerebral edema and the associated motor deficits. Following trauma, BBG treatment significantly reduced the levels of PKCγ and interleukin-1ß in the cortex. The results provide in vivo evidence that BBG exerted neuroprotective effects by attenuating brain edema and improving neurological functions via reducing PKCγ and interleukin-1ß levels following TBI.

Neuronic autophagy contributes to p-connexin 43 degradation in hippocampal astrocytes following traumatic brain injury in rats.

Connexins, gap junction proteins, have short half­lives of only a few hours; therefore, degradation of these proteins can rapidly modulate their function. Autophagy is a type of degradation pathway that has been implicated in several diseases and was reported to be induced following traumatic brain injury (TBI). The aim of the present study was to investigate the involvement of neuronic autophagy in proteolysis of phosphorylated connexin 43 (p­Cx43) in hippocampal astrocytes following TBI in rats. Western blot analysis and immunofluorescence showed a TBI­induced increase in levels of astrocytic p­Cx43 following treatment with 3­methyladenine, an inhibitor of autophagy, in the hippocampus. Internalized gap junctions were observed in the neuronic cytoplasm using transmission electron microscopy. These results demonstrated that neuronic autophagy may regulate cellular levels of p­Cx43 in hippocampal astrocytes following TBI. This therefore indicated that the persistence of p­Cx43 accumulation was due to insufficient degradation capacity of constitutive autophagy.

Astrocytic p-connexin 43 regulates neuronal autophagy in the hippocampus following traumatic brain injury in rats.

Gap junctions are conductive channels formed by membrane proteins termed connexins, which permit the intercellular exchange of metabolites, ions and small molecules. Previous data demonstrated that traumatic brain injury (TBI) activates autophagy and increases microtubule­associated protein 1 light chain 3 (LC3) immunostaining predominantly in neurons. Although previous studies have identified several extracellular factors that modulate LC3 expression, knowledge of the regulatory network controlling LC3 in health and disease remains incomplete. The aim of the present study was to assess whether gap junctions control the in vivo expression of LC3 in TBI. Using a modified weight­drop device, adult male Sprague­Dawley rats (weight, 350­375 g) were subjected to TBI. Phosphorylated gap junction protein levels and LC3­â…¡ levels were quantified using western blot analysis. The spatial distribution of immunoreactivity for phosphorylated connexin 43 (p­CX43) and LC3­â…¡ was analyzed by immunofluorescence. The results showed that p­CX43 expression in the hippocampus reached a maximum level 6 h following injury. In addition, the immunoreactivity of p­CX43 was localized in the astrocytes surrounding pyramidal neurons. The LC3­â…¡ protein content remained at high levels 24 h following injury. Double immunolabeling demonstrated that LC3­II dots colocalized with the hippocampus pyramidal neurons. Furthermore, inhibition of p­CX43 reduced TBI­induced autophagy, according to western blot analysis. As astrocytic gap junction coupling is affected in various forms of brain injury, the results suggest that point gap junctions/connexins are important regulators of autophagy in the hippocampal neurons following TBI.

Terson syndrome with no cerebral hemorrhage: A case report.

The present study reports the case of a 33-year-old male who presented with Terson syndrome with no cerebral hemorrhage secondary to traumatic brain injury (TBI). A computed tomography scan of the patient, who had sustained an impact injury to the right occipital region, showed no cerebral lesion. Ophthalmoscopy clearly demonstrated vitreous hemorrhage in both eye globes. Vitreous hemorrhage, which results from an abrupt increase in intracranial pressure (ICP), is associated with TBI. In this case, the visual disturbance was attributed to Terson syndrome secondary to TBI. Therefore, close ophthalmological and radiological evaluation is required in patients with TBI, in order to enable the diagnosis of Terson syndrome and an early vitrectomy.

Expression and significance of the Wip1 proto-oncogene in colorectal cancer.

AIM: To investigate the level of expression of proto-oncogene Wip1 and its physiological significance in colorectal cancer. METHODS: Immunohistochemistry, semi-quantitative RT-PCR, and Western blotting were used to analyze Wip1 mRNA and protein expression in 120 cases of colorectal cancer and normal tissues to study relationships with clinical symptoms and disease prognosis. RESULTS: The level of Wip1 protein expression was found to be significantly higher in colorectal cancer tissues (85% (102/120)) than in normal tissues (30% (36/120)) (P < 0.05). The relative amount of Wip1 protein in colorectal cancer tissue was also found to be significantly higher (P < 0.05) than in normal tissues (1.060±0.02 and 0.640±0.023, respectively). Semi-quantitative RT-PCR showed average Wip1 mRNA expression levels to be 1.113 ±0.018 and 0.658±0.036 for colorectal cancer tissue and adjacent normal tissue (P < 0.05). The level of Wip1 protein expression was not correlated with age, gender, or tumor site, but appeared linked with lymph node metastasis, Dukes stage, histological grade, and liver metastasis. Individuals with high and low levels of Wip1 expression showed statistically significant differences in the five-year overall survival and recurrence-free survival rates (P < 0.05). CONCLUSION: Wip1 mRNA and protein are highly expressed in colorectal cancers and may be associated with colorectal cancer development and progression.