Mild hypothermia protects against oxygen glucose deprivation (OGD)-induced cell death in brain slices from adult mice

Most of neuroprotective strategies in stroke have failed to move from bench to bedside. One explanation might be the use of excessive uniform and smooth experimental models. Therefore, we have employed a more stringent in vitro model based on cultured brain slices from adult mice submitted to OGD. Using this acute model, we have confirmed that mild hypothermia protects against OGD-induced cell death when cooling the tissue during and after OGD, but not when hypothermia is induced only during reoxygenation.     

Static magnetic fields modulate X-ray-induced DNA damage in human glioblastoma primary cells

Although static magnetic fields (SMFs) are used extensively in the occupational and medical fields, few comprehensive studies have investigated their possible genotoxic effect and the findings are controversial. With the advent of magnetic resonance imaging-guided radiation therapy, the potential effects of SMFs on ionizing radiation (IR) have become increasingly important. In this study we focused on the genotoxic effect of 80 mT SMFs, both alone and in combination with (i.e. preceding or following) X-ray (XR) irradiation, on primary glioblastoma cells in culture. The cells were exposed to: (i) SMFs alone; (ii) XRs alone; (iii) XR, with SMFs applied during recovery; (iv) SMFs both before and after XR irradiation. XR-induced DNA damage was analyzed by Single Cell Gel Electrophoresis assay (comet assay) using statistical tools designed to assess the tail DNA (TD) and tail length (TL) as indicators of DNA fragmentation. Mitochondrial membrane potential, known to be affected by IR, was assessed using the JC-1 mitochondrial probe. Our results showed that exposure of cells to 5 Gy of XR irradiation alone led to extensive DNA damage, which was significantly reduced by post-irradiation exposure to SMFs. The XR-induced loss of mitochondrial membrane potential was to a large extent averted by exposure to SMFs. These data suggest that SMFs modulate DNA damage and/or damage repair, possibly through a mechanism that affects mitochondria.     

Chronic schizophrenia is associated with over-expression of the interleukin-2 receptor gamma gene

Altered immune response, including low-grade inflammatory processes, is involved in the pathogenesis of schizophrenia, a chronic psychiatric disorder with complex etiology. Distinct gene variants of a number of pro-inflammatory and chemotactic cytokines together with their receptors associate with this disorder. Interleukin-2 receptor gamma (IL-2RG) represents an important signaling component of many interleukin receptors and so far, no data on the functional state of this receptor in schizophrenia have been reported. The aim of this study was to investigate mRNA expression of the IL2RG gene (IL2RG) in schizophrenia patients in comparison with healthy subjects (controls). Total RNA was isolated from peripheral blood of 66 schizophrenia patients and 99 healthy subjects of Armenian population. The mRNA expression was determined by quantitative real-time polymerase chain reaction (RT-PCR) using PSMB2 as housekeeping gene. IL2RG mRNA expression was upregulated in peripheral blood of patients in comparison with controls (patients vs. controls, median [interquartile range]: 2.080 [3.428–1.046] vs. 0.324 [0.856–0.000], p<0.0001). In conclusion, our findings suggest that over-expression of the IL2RG gene may be implicated in altered immune response in schizophrenia and contribute to the pathomechanisms of this disorder.     

Characterization of a Factor H Mutation That Perturbs the Alternative Pathway of Complement in a Family with Membranoproliferative GN

Complement C3 activation is a characteristic finding in membranoproliferative GN (MPGN). This activation can be caused by immune complex deposition or an acquired or inherited defect in complement regulation. Deficiency of complement factor H has long been associated with MPGN. More recently, heterozygous genetic variants have been reported in sporadic cases of MPGN, although their functional significance has not been assessed. We describe a family with MPGN and acquired partial lipodystrophy. Although C3 nephritic factor was shown in family members with acquired partial lipodystrophy, it did not segregate with the renal phenotype. Genetic analysis revealed a novel heterozygous mutation in complement factor H (R83S) in addition to known risk polymorphisms carried by individuals with MPGN. Patients with MPGN had normal levels of factor H, and structural analysis of the mutant revealed only subtle alterations. However, functional analysis revealed profoundly reduced C3b binding, cofactor activity, and decay accelerating activity leading to loss of regulation of the alternative pathway. In summary, this family showed a confluence of common and rare functionally significant genetic risk factors causing disease. Data from our analysis of these factors highlight the role of the alternative pathway of complement in MPGN.     

Differential Ly6C Expression after Renal Ischemia-Reperfusion Identifies Unique Macrophage Populations

Macrophages are a heterogeneous cell type implicated in injury, repair, and fibrosis after AKI, but the macrophage population associated with each phase is unclear. In this study, we used a renal bilateral ischemia-reperfusion injury mouse model to identify unique monocyte/macrophage populations by differential expression of Ly6C in CD11b⁺ cells and to define the function of these cells in the pathophysiology of disease on the basis of microarray gene signatures and reduction strategies. Macrophage populations were isolated from kidney homogenates by fluorescence-activated cell sorting for whole genome microarray analysis. The CD11b⁺/Ly6C^high population associated with the onset of renal injury and increase in proinflammatory cytokines, whereas the CD11b⁺/Ly6C^intermediate population peaked during kidney repair. The CD11b⁺/Ly6C^low population emerged with developing renal fibrosis. Principal component and hierarchical cluster analyses identified gene signatures unique to each population. The CD11b⁺/Ly6C^intermediate population had a distinct phenotype of wound healing, confirmed by results of studies inhibiting the macrophage colony-stimulating factor 1 receptor,whereas the CD11b⁺/Ly6C^low population had a profibrotic phenotype. All populations, including the CD11b⁺/Ly6C^high population, carried differential inflammatory signatures. The expression of M2-specific markers was detected in both the CD11b⁺/Ly6C^intermediate and CD11b⁺/Ly6C^low populations, suggesting these in vivo populations do not fit into the traditional classifications defined by in vitro systems. Results of this study in a renal ischemia-reperfusion injury model allow phenotype and function to be assigned to CD11b⁺/Ly6C⁺ monocyte/macrophage populations in the pathophysiology of disease after AKI.