Impact of Xenon on CLIC4 and Bcl-2 Expression in Lipopolysaccharide and Hypoxia-Ischemia-Induced Periventricular White Matter Damage

Abstract

Background: Premature birth is a significant health care burden. Xenon (Xe) is a general anesthetic with neuroprotective effects. Objectives: Here, we investigate the neuroprotective role of Xe in a lipopolysaccharide (LPS)- and hypoxia-ischemia (HI)-induced white matter damage (WMD) model. Methods: Three-day-old Sprague-Dawley rats were randomly divided into a sham group (group A, n = 24), an LPS + HI group (group B, n = 24), and an LPS + HI + Xe group (group C, n = 72). The onset of Xe inhalation started at 0, 2, and 5 h in subgroups C1, C2, and C3, respectively. Next, we performed TUNEL and hematoxylin and eosin (HE) staining; and examined the expression of CLIC4 and Bcl-2 in brain tissues. Results: HE staining revealed distorted cytoarchitecture, tangled nerve fibers, and pyknosis in group B, while Xe treatment improved these histological alterations in the group C pups. Following LPS and HI insult, the number of apoptotic cells significantly increased in group B at 48 and 72 h (p < 0.05), and Xe significantly alleviated apoptosis (p < 0.001) at 24, 48, and 72 h, respectively. Similarly, CLIC4 mRNA expression was significantly increased in group B (p < 0.05), and Xe produced a marked reduction in CLIC4 mRNA expression in group C subgroups (p < 0.05). Western blotting demonstrated enhanced Bcl-2 expression in group C when compared to group B (p < 0.05). Conclusions: These results demonstrate that LPS and HI successfully induced WMD, and Xe decreased neuronal apoptosis via Bcl-2- and CLIC4-mediated pathways. Moreover, the therapeutic time window of Xe extended for up to 5 h. These findings suggest that Xe can be used as a protective treatment for WMD in premature infants.

The neuroprotective effects of xenon on neonatal rats with white matter damage by regulating expression of microRNA-210 and HIF-1α

“…[14,15,39] Xenon has well documented neuroprotective properties that were reported in models of premature brain injury, [7,10,11,39]as shown in our previous papers. [19]In this study, we investigated the acute neuroprotective outcomes of xenon in an in vivo model of premature brain injury. In accordance with previous reports, we opted to use a 3-hour xenon treatment interval.…”

“…First, we examined the efficiency of LPS and HI in inducing WMD in P3 rat pups as we have done previously [19]. In Group A ,HE staining of brain tissue demonstrated a normal white matter structure and morphology,regular cell arrangement with intact,centrally-positioned nuclei and a clear entoblast at 0, 24, 48 and 72 hours ( Fig.1 A-…”

“…As we have done previously [19] ,Pups were either administered lipopolysaccharide (LPS, 0.05 mg/kg, Escherichia coli 0111:B4; Sigma, USA) or normal saline (NS, Sham group) via intraperitoneal (i.p) injection. To avoid LPS-induced body temperature changes, pups were housed with their mothers after LPS or NS injection in an incubator for 3 hours to maintain their body temperature at 33 to 34°C before HI.…”

“…Brains were excised as described previously. [19] Briefly, pups were anesthetized with chloral hydrate and fixed on an operating panel. Next, the heart was exposed and a 10 ml syringe with 4% paraformaldehyde was inserted from the left ventricle to the aorta.…”

The neuroprotective effects of xenon on neonatal rats with white matter damage by regulating expression of microRNA-210 and HIF-1α

“…[14,15,40] Xenon has well documented neuroprotective properties that were reported in models of premature brain injury, [7,10,11,40]as shown in our previous papers. [41]In this study, we investigated the acute neuroprotective outcomes of xenon in an in vivo model of premature brain injury. In accordance with previous reports, we opted to use a 3-hour xenon treatment interval.…”