Chronic diazepam administration increases the expression of Lcn2 in the CNS

Abstract

Benzodiazepines (BZDs), which bind with high affinity to gamma‐aminobutyric acid type A receptors (GABAA‐Rs) and potentiate the effects of GABA, are widely prescribed for anxiety, insomnia, epileptic discharge, and as anticonvulsants. The long‐term use of BZDs is limited due to adverse effects such as tolerance, dependence, withdrawal effects, and impairments in cognition and learning. Additionally, clinical reports have shown that chronic BZD treatment increases the risk of Alzheimer's disease. Unusual GABAA‐R subunit expression and GABAA‐R phosphorylation are induced by chronic BZD use. However, the gene expression and signaling pathways related to these effects are not completely understood. In this study, we performed a microarray analysis to investigate the mechanisms underlying the effect of chronic BZD administration on gene expression. Diazepam (DZP, a BZD) was chronically administered, and whole transcripts in the brain were analyzed. We found that the mRNA expression levels were significantly affected by chronic DZP administration and that lipocalin 2 (Lcn2) mRNA was the most upregulated gene in the cerebral cortex, hippocampus, and amygdala. Lcn2 is known as an iron homeostasis‐associated protein. Immunostained signals of Lcn2 were detected in neuron, astrocyte, microglia, and Lcn2 protein expression levels were consistently upregulated. This upregulation was observed without proinflammatory genes upregulation, and was attenuated by chronic treatment of deferoxamine mesylate (DFO), iron chelator. Our results suggest that chronic DZP administration regulates transcription and upregulates Lcn2 expression levels without an inflammatory response in the mouse brain. Furthermore, the DZP‐induced upregulation of Lcn2 expression was influenced by ambient iron.

Low dose γ radiation enhances antidepressant effect of resveratrol: Behavioral and neurochemical studies

“…Studies have also revealed cellular changes after diazepam treatment. 14,55 On the other hand, low dose gamma radiation or resveratrol treatments prior to diazepam treated mice showed a noticeable enhancement in the overall histo-architecture of brain areas, which may be accredited to their neuroprotective role in reducing the levels of free radicals and regulating the activities of antioxidant enzymes thereby preventing cellular damage. 14 Besides, brain sections of LDR and resveratrol treatment group showed the same histological picture of control normal group and improvement than diazepam group.…”

Neutrophil extracellular traps (NETs) contribute to pathological changes of ocular graft-vs.-host disease (oGVHD) dry eye: Implications for novel biomarkers and therapeutic strategies

“…Immunofluorescent staining: The OSW and MCA samples were permeabilized with 0.025% Triton X-100 (Fisher Scientific, #BP151-100), and blocked with freshly prepared 10% Donkey serum with 1% Bovine Serum Albumin (Gemini Bio-Products, #700-100P) for 2 hours. After blocking, the following primary antibodies were applied, and left overnight at 4˚C: mouse monoclonal anti-human neutrophil elastase (NE) (1:100, Dako, Clone NP57, #M0752); 56,57 rabbit polyclonal to histone H3 (1:100, citrulline R2+R8+R17, 1:100, Abcam, #ab5103); 58,59 rabbit polyclonal Keratin-14 (1:1000, BioLegend, #905301, Covance #PRB-155P); 60,61 rabbit polyclonal anti-human Myeloperoxidase (MPO) (1:100, Abcam, #ab45977); 62,63 rabbit monoclonal anti-human CD3 (1:100, Abcam, #ab16669); 64,65 rabbit polyclonal anti-Oncostatin M (LifeSpan Biosciences, #LS-C104796); rabbit polyclonal NGAL (1:100, Abcam, #ab63929); 66,67 and rabbit polyclonal LIGHT/TNFSF14 (1:100, LifeSpan Biosciences, #LS-C118682). Isotype controls were used as negative controls.…”

Lipocalin‐2: Its perspectives in brain pathology and possible roles in cognition

“…Under physiological conditions in a murine model, the expression of LCN2 mRNA and LCN2 protein in the brain appears to be very low to absent . However, only a few studies have reported LCN2 protein expression in the hippocampus, cortex and amygdala of normal mice and the hippocampus of normal adult rats …”

“…LCN2 had no effect on cognitive function in basal condition 30 very low to absent. 6,8,11,[24][25][26] However, only a few studies have reported LCN2 protein expression in the hippocampus, 27,28 cortex and amygdala 28 of normal mice and the hippocampus of normal adult rats. 10 Several studies have shown no significant difference between the cognitive function of wild-type mice and LCN2 null mice (Table 1).…”

“…22 Although previous studies have shown that LCN2 is undetectable in the brain under physiological conditions, 6,8,11,[24][25][26] other studies showed that LCN2 is expressed only in specific brain regions. 10,27,28 In addition, the up-regulation of brain LCN2 expression has been found to occur in response to injury and inflammation 7 and it has been suggested that LCN2 could modulate cognitive function in Alzheimer's disease (AD). 29 Despite this, from the available evidence to date, any association between LCN2 and cognitive function remains unclear.…”