PMID- 34776788 OWN - NLM STAT- MEDLINE DCOM- 20220331 LR - 20220531 IS - 1466-1861 (Electronic) IS - 0962-9351 (Print) IS - 0962-9351 (Linking) VI - 2021 DP - 2021 TI - Cooling and Sterile Inflammation in an Oxygen-Glucose-Deprivation/Reperfusion Injury Model in BV-2 Microglia. PG - 8906561 LID - 10.1155/2021/8906561 [doi] LID - 8906561 AB - OBJECTIVE: Cold-inducible RNA-binding protein (CIRBP) has been shown to be involved not only in cooling-induced cellular protection but also as a mediator of sterile inflammation, a critical mechanism of the innate immune response in ischemia/reperfusion (I/R) injury. The role of microglia and its activation in cerebral I/R injury warrants further investigation as both detrimental and regenerative properties have been described. Therefore, we investigated the effects of cooling, specifically viability, activation, and release of damage associated molecular patterns (DAMPs) on oxygen glucose deprivation/reperfusion- (OGD/R-) induced injury in murine BV-2 microglial cells. METHODS: Murine BV-2 microglial cells were exposed to 2 to 6 h OGD (0.2% O(2) in glucose- and serum-free medium) followed by up to 19 h of reperfusion, simulated by restoration of oxygen (21% O(2)) and nutrients. Cells were maintained at either normothermia (37 degrees C) or cooled to 33.5 degrees C, 1 h after experimental start. Cultured supernatants were harvested after exposure to OGD for analysis of DAMP secretions, including high-mobility group box 1 (HMGB1), heat shock protein 70 (HSP70), and CIRBP, and cytotoxicity was assessed by lactate dehydrogenase releases after exposure to OGD and reperfusion. Intracellular cold-shock proteins CIRBP and RNA-binding motif 3 (RBM3) as well as caspases 9, 8, and 3 were also analyzed via Western blot analysis. Furthermore, inducible nitric oxide synthase (iNOS), ionized calcium-binding adaptor molecule 1 (Iba1), tumor necrosis factor-alpha (TNF-alpha), interleukin-6 (IL-6), interleukin-1beta (IL-1beta), interleukin-1alpha (IL-1alpha), monocyte chemotactic protein 1 (MCP-1), transforming growth factor beta (TGFbeta), CIRBP, and RBM3 gene expressions were assessed via reverse transcription polymerase chain reaction, and TNF-alpha, IL-6, and IL-1beta releases into the cultured supernatants were assessed via enzyme-linked immunosorbent assays (ELISA). RESULTS: Prolonged exposure to OGD resulted in increased BV-2 necrotic cell death, which was attenuated by cooling. Cooling also significantly induced cold-shock proteins CIRBP and RBM3 gene expressions, with CIRBP expression more rapidly regulated than RBM3 and translatable to significantly increased protein expression. DAMPs including HMGB-1, HSP70, and CIRBP could be detected in cultured supernatants after 6 h of OGD with CIRBP release being significantly attenuated by cooling. Exposure to OGD suppressed cytokine gene expressions of IL-1beta, TNF-alpha, MCP-1, and TGFbeta independently of temperature management, whereas cooling led to a significant increase in IL-1alpha gene expression after 6 h of OGD. In the reperfusion phase, TNF-alpha and MCP-1 gene expressions were increased, and cooling was associated with significantly lower TGFbeta gene expression. Interestingly, cooled Normoxia groups had significant upregulations of microglial activation marker, Iba1, IL-1beta, and TNF-alpha gene expressions. CONCLUSION: BV-2 microglial cells undergo necrotic cell death resulting in DAMP release due to OGD/R-induced injury. Cooling conveyed neuroprotection in OGD/R-injury as observable in increased cell viability as well as induced gene expressions of cold shock proteins. As cooling alone resulted in both upregulation of microglial activation, expression of proinflammatory cytokines, and cold shock protein transcript and protein expression, temperature management might have ambiguous effects in sterile inflammation. However, cooling resulted in a significant decrease of extracellular CIRBP, which has recently been characterized as a novel DAMP and a potent initiator and mediator of inflammation. CI - Copyright (c) 2021 Jana Lucht et al. FAU - Lucht, Jana AU - Lucht J AUID- ORCID: 0000-0001-8687-8313 AD - German Heart Centre Berlin, Department of Congenital Heart Disease/Pediatric Cardiology, Berlin, Germany. AD - Berlin Institute of Health, Berlin, Germany. FAU - Rolfs, Nele AU - Rolfs N AUID- ORCID: 0000-0003-2552-5463 AD - German Heart Centre Berlin, Department of Congenital Heart Disease/Pediatric Cardiology, Berlin, Germany. FAU - Wowro, Sylvia J AU - Wowro SJ AUID- ORCID: 0000-0003-1728-9210 AD - Charite-Universitatsmedizin Berlin, Department of Congenital Heart Disease/Pediatric Cardiology, Berlin, Germany. FAU - Berger, Felix AU - Berger F AUID- ORCID: 0000-0001-7881-1557 AD - German Heart Centre Berlin, Department of Congenital Heart Disease/Pediatric Cardiology, Berlin, Germany. AD - Charite-Universitatsmedizin Berlin, Department of Congenital Heart Disease/Pediatric Cardiology, Berlin, Germany. FAU - Schmitt, Katharina R L AU - Schmitt KRL AUID- ORCID: 0000-0003-0860-1137 AD - German Heart Centre Berlin, Department of Congenital Heart Disease/Pediatric Cardiology, Berlin, Germany. AD - Charite-Universitatsmedizin Berlin, Department of Congenital Heart Disease/Pediatric Cardiology, Berlin, Germany. FAU - Tong, Giang AU - Tong G AUID- ORCID: 0000-0002-3470-9750 AD - German Heart Centre Berlin, Department of Congenital Heart Disease/Pediatric Cardiology, Berlin, Germany. LA - eng PT - Journal Article DEP - 20211105 PL - United States TA - Mediators Inflamm JT - Mediators of inflammation JID - 9209001 RN - 0 (Cirbp protein, mouse) RN - 0 (RNA-Binding Proteins) RN - 0 (Rbm3 protein, mouse) RN - IY9XDZ35W2 (Glucose) RN - S88TT14065 (Oxygen) SB - IM MH - Animals MH - *Cold Temperature MH - Glucose/metabolism MH - *Inflammation/metabolism MH - Mice MH - *Microglia/metabolism MH - Oxygen/metabolism MH - RNA-Binding Proteins/metabolism MH - *Reperfusion Injury PMC - PMC8589512 COIS- The authors declare that they have no conflicts of interest. EDAT- 2021/11/16 06:00 MHDA- 2022/04/01 06:00 PMCR- 2021/11/05 CRDT- 2021/11/15 06:54 PHST- 2021/09/02 00:00 [received] PHST- 2021/10/02 00:00 [accepted] PHST- 2021/11/15 06:54 [entrez] PHST- 2021/11/16 06:00 [pubmed] PHST- 2022/04/01 06:00 [medline] PHST- 2021/11/05 00:00 [pmc-release] AID - 10.1155/2021/8906561 [doi] PST - epublish SO - Mediators Inflamm. 2021 Nov 5;2021:8906561. doi: 10.1155/2021/8906561. eCollection 2021.