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

Abstract

Abstract. 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-1β (IL-1β) 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 FK866 against traumatic brain injury: Involvement of p38/ERK pathway

“…Morris water maze test was conducted as previously described 18 . Briefly, the rat was trained to find the platform before TBI or sham operation.…”

Pharmacological modulation of autophagy: therapeutic potential and persisting obstacles

“…Of note, melatonin has been suggested to inhibit autophagy in other settings 73 . Moreover, post-injury chloroquine administration limited neuronal damage and improved neurological recovery in rats that were subjected to controlled cortical impact 104 , as did 3-MA and BafA1 administered as a prophylactic intervention in a mouse weight-drop model 105 . Thus, autophagy activators may be beneficial for patients experiencing SCI or SAH, even if administered in a therapeutic (as opposed to prophylactic) setting.…”

Hsp70 inducer, 17-allylamino-demethoxygeldanamycin, provides neuroprotection via anti-inflammatory effects in a rat model of traumatic brain injury

“…Coronal sections (10 µm) were obtained from the anterior area of the left hemisphere. Immunofluorescence was performed as described previously (15). Briefly, brain tissue samples were fixed in 4% paraformaldehyde (Bio-Rad Laboratories, Inc.) for 24 h, then transferred to a 30% sucrose solution containing 0.1 mol/l phosphate-buffered saline (PBS; pH 7.4).…”

“…Western blot analysis was performed as previously described (15). Briefly, rats were anesthetized and underwent intracardiac perfusion with 0.1 mol/l PBS (pH 7.4).…”

“…Motor function was evaluated as described previously (15). Neurologic Severity Score (NSS) was evaluated at 1, 3, 5 and 7 days (15).…”