The correlation between cytokine production by cerebral cortical glial cells and brain lateralization in mice

Interleukin-6 in Traumatic Brain Injury: A Janus-Faced Player in Damage and Repair

Traumatic brain injury (TBI) is a common and often devastating illness, with wide-ranging public health implications. In addition to the primary injury, victims of TBI are at risk for secondary neurological injury by numerous mechanisms. Current treatments are limited and do not target the profound immune response associated with injury. This immune response reflects a convergence of peripheral and central nervous system-resident immune cells whose interaction is mediated in part by a disruption in the blood-brain barrier (BBB). The diverse family of cytokines helps to govern this communication and among these, Interleukin (IL)-6 is a notable player in the immune response to acute neurological injury. It is also a well-established pharmacological target in a variety of other disease contexts. In TBI, elevated IL-6 levels are associated with worse outcomes, but the role of IL-6 in response to injury is double-edged. IL-6 promotes neurogenesis and wound healing in animal models of TBI, but it may also contribute to disruptions in the BBB and the progression of cerebral edema. Here, we review IL-6 biology in the context of TBI, with an eye to clarifying its controversial role and understanding its potential as a target for modulating the immune response in this disease.

Effect of ATM on inflammatory response and autophagy in renal tubular epithelial cells in LPS-induced septic AKI

The aim of the present study was to explore the role of ataxia-telangiectasia mutated (ATM) in lipopolysaccharide (LPS)-induced in vitro model of septic acute kidney injury (AKI) and the association between ATM, tubular epithelial inflammatory response and autophagy. The renal tubular epithelial cell HK-2 cell line was cultured and passaged, with HK-2 cell injury induced by LPS. The effects of LPS on HK-2 cell morphology, viability, ATM expression and inflammation were observed. Lentiviral vectors encoding ATM shRNA were constructed to knock down ATM expression in HK-2 cells. The efficiency of ATM knockdown in HK-2 cells was detected by western blot analysis and reverse transcription-quantitative PCR (RT-qPCR). HK-2 cells transfected with the ATM shRNA lentivirus were used for subsequent experiments. Following ATM knockdown, corresponding controls were set up, and the effects of ATM on inflammation and autophagy were detected in HK-2 cells using RT-qPCR, western blotting and ELISA. After LPS stimulation, the HK-2 cells were rounded into a slender or fusiform shape with poorly defined outlines. LPS treatment reduced cell viability in a partly dose-dependent manner. LPS increased the expression of tumor necrosis factor-α, interleukin (IL)-1β and IL-6, with the levels reaching its highest value at 10 µg/ml. IL-6 and IL-1β expression increased with increasing LPS concentration. These findings suggest that LPS reduced HK-2 cell viability whilst increasing the expression of inflammatory factors. Following transfection with ATM shRNA, expression levels of key autophagy indicators microtubule associated protein 1 light chain 3α I/II ratio and beclin-1 in the two ATM shRNA groups were also significantly reduced compared with the NC shRNA group. In summary, downregulation of ATM expression in HK-2 cells reduced LPS-induced inflammation and autophagy in sepsis-induced AKI in vitro, suggesting that LPS may induce autophagy in HK-2 cells through the ATM pathway leading to the upregulation of inflammatory factors.

Asymmetric production of nitric oxide in mouse primary cortical mixed glial cell cultures treated with lipopolysaccharide

Activated glial cells produce many toxic molecules, including cytokines and nitric oxide (NO). There is evidence that excess NO production plays a key role in neuronal cell death. Previous research has demonstrated that cortical glial cells from the left and right cortices of the brain secrete cytokines asymmetrically. However, no evidence to date exists about whether glial cell-produced NO is produced asymmetrically as well. The results of this study show that NO production and inducible NO synthase gene expression are both significantly higher in the right hemisphere-derived mixed glial cell compared with cultures derived from the left.

Lipopolysaccharide enhances asymmetrical production of cytokines and nitric oxide by left and right cerebral cortical microglial cells in BALB/C mice

Lipopolysaccharide (LPS)-induced inflammatory factors production by the cerebral cortical glial cells in two sides of the murine brain are different. To determine if microglial cells, a subset of glial cells, are involved in asymmetric production, interleukin-6 (IL-6), interleukin-1β (IL-1β) and nitric oxide (NO) responses to LPS by microglial cells in the right and left cerebral cortices were examined. Primary microglial cells were isolated from BALB/C neonatal mice, treated with LPS (10 µg ml(-1) ) for 24 h and examined for IL-6, IL-1β and NO production. At untreated state, the levels of IL-6, IL-1β and NO showed no statistical difference between left and right. However, after LPS treatment, the levels of IL-6, IL-1β and NO for the right microglial cells was statistically significant higher than the left (P < 0·05). Our results denote that enhanced production of IL-6, IL-1β and NO after LPS treatment in microglia is directly proportional to their basal-state levels, and right cortical microglia produce higher levels of IL-6, IL-1β and NO than left cortical microglia.