scholarly journals 4163 Aging and Smoking Exacerbates Post-Stroke Complement Driven Neuroinflammation

2020 ◽  
Vol 4 (s1) ◽  
pp. 1-1
Author(s):  
Christine Couch

OBJECTIVES/GOALS: Following stroke, complement-dependent neuroinflammation exacerbates secondary injury and worsens acute and chronic outcomes. We have shown that an injury site-targeted complement inhibitor (B4Crry), that targets specifically to the ischemic brain, inhibits complement activation leading to improved outcomes. Stroke comorbidities have been shown to promote a pro-inflammatory environment in the brain and systemically, and to exacerbate inflammatory responses after injury. We investigated the impact of age and smoking on acute outcomes after stroke and assessed whether increased complement activation contributes to the worsening outcomes with these stroke comorbidities. METHODS/STUDY POPULATION: Mouse brain endothelial cells (bEnd3) were exposed to hypoxia followed by exposure to serum that was derived from either cigarette smoke (CS)-exposed mice or naïve mice, and IgM and C3d deposition assessed. Adult (12 weeks) and aged (1 year) mice were subjected to 1h transient middle cerebral artery occlusion. Animals were exposed to CS for 3-6 months (5hr/day, 5days/week) by burning 3R4F cigarettes using a smoking machine. Animals were treated with B4Crry or vehicle intravenously 2h post-MCAO. Survival analysis and neurological deficit scores were performed up to 7 days. Brains were extracted for histological and molecular analyses. RESULTS/ANTICIPATED RESULTS: Following hypoxia, bEnd3 cells exposed to serum from CS-exposed mice had higher C3d and IgM deposition compared to naïve serum. Older and CS-exposed mice had significantly worse neurological deficits and mortality compared to younger adults post-MCAO. B4Crry reduced mortality and motor deficits in young, old and old+CS mice with a higher effect size in comorbid animals. Age and/or CS exposure resulted in larger infarct volumes, and increased levels of C3d deposition and microglial activation compared to young adults, but aged/CS animals treated with B4Crry fared comparable to young adults. DISCUSSION/SIGNIFICANCE OF IMPACT: The pro-inflammatory effects of aging and smoking contribute to worse stroke outcomes, and these effects can be successfully mitigated by injury site-targeted complement inhibition.

2007 ◽  
Vol 28 (1) ◽  
pp. 53-63 ◽  
Author(s):  
Zhen Zheng ◽  
Jong Youl Kim ◽  
Hualong Ma ◽  
Jong Eun Lee ◽  
Midori A Yenari

The 70-kDa heat shock protein (Hsp70) is involved in protecting the brain from a variety of insults including stroke. Although the mechanism has been largely considered to be because of its chaperone functions, recent work indicates that Hsp70 also modulates inflammatory responses. To explore how and whether Hsp70 regulate immune responses in brain ischemia, mice overexpressing Hsp70 (Hsp Tg) were subjected to 2 h middle cerebral artery occlusion, followed by 24 h reperfusion. Parallel experiments were performed using a brain inflammation model. Hsp Tg microglia cocultured with astrocytes were used to evaluate the direct effects of Hsp70 on cytotoxicity of mcrigolia. Compared with wild-type (Wt) littermates, Hsp Tg mice showed decreased infarct size and improved neurological deficits. The number of activated microglia/macrophages were also reduced in ischemic brains of Hsp Tg mice. Similar observations were made in a model of brain inflammation that does not result in brain cell death. Overexpression of Hsp70 in microglia completely prevented microglia-induced cytotoxicity to astrocytes. Activation of the inflammatory transcription factor, nuclear factor-κB (NF-κB) was inhibited significantly in Hsp Tg mice and microglia. This was associated with decreased phosphorylation of NF-κB inhibitor protein, IκBα, and decreased expression of several NFκB-regulated genes. Co-immunoprecipitation studies revealed an interaction of Hsp70 with NF-κB and IκBα, but not with IkB kinase, IKKγ, suggesting that Hsp70 binds to the NF-κB:IκB complex preventing IκB phosphorylation by IKK. The findings of the present work establish an anti-inflammatory role for Hsp70 in the context of brain ischemia as a novel mechanism of protection.


2016 ◽  
Vol 397 (12) ◽  
pp. 1277-1286 ◽  
Author(s):  
Hyesook Yoon ◽  
Isobel A. Scarisbrick

Abstract Kallikrein-related peptidase 6 (Klk6) is elevated in the serum of multiple sclerosis (MS) patients and is hypothesized to participate in inflammatory and neuropathogenic aspects of the disease. To test this hypothesis, we investigated the impact of systemic administration of recombinant Klk6 on the development and progression of MOG35-55-induced experimental autoimmune encephalomyelitis (EAE). First, we determined that Klk6 expression is elevated in the spinal cord of mice with EAE at the peak of clinical disease and in immune cells upon priming with the disease-initiating peptide in vitro. Systemic administration of recombinant Klk6 to mice during the priming phase of disease resulted in an exacerbation of clinical symptoms, including earlier onset of disease and higher levels of spinal cord inflammation and pathology. Treatment of MOG35-55-primed immune cells with Klk6 in culture enhanced expression of pro-inflammatory cytokines, interferon-γ, tumor necrosis factor, and interleukin-17, while reducing anti-inflammatory cytokines interleukin-4 and interleukin-5. Together these findings provide evidence that elevations in systemic Klk6 can bias the immune system towards pro-inflammatory responses capable of exacerbating the development of neuroinflammation and paralytic neurological deficits. We suggest that Klk6 represents an important target for conditions in which pro-inflammatory responses play a critical role in disease development, including MS.


2019 ◽  
Vol 20 (20) ◽  
pp. 5184 ◽  
Author(s):  
Sarah Lunardi Baccetto ◽  
Christian Lehmann

Stroke is the second-leading cause of death globally and the leading cause of disability in adults. Medical complications after stroke, especially infections such as pneumonia, are the leading cause of death in stroke survivors. Systemic immunodepression is considered to contribute to increased susceptibility to infections after stroke. Different experimental models have contributed significantly to the current knowledge of stroke pathophysiology and its consequences. Each model causes different changes in the cerebral microcirculation and local inflammatory responses after ischemia. The vast majority of studies which focused on the peripheral immune response to stroke employed the middle cerebral artery occlusion method. We review various experimental stroke models with regard to microcirculatory changes and discuss the impact on local and peripheral immune response for studies of CNS-injury (central nervous system injury) induced immunodepression.


Crisis ◽  
2016 ◽  
Vol 37 (4) ◽  
pp. 265-270 ◽  
Author(s):  
Meshan Lehmann ◽  
Matthew R. Hilimire ◽  
Lawrence H. Yang ◽  
Bruce G. Link ◽  
Jordan E. DeVylder

Abstract. Background: Self-esteem is a major contributor to risk for repeated suicide attempts. Prior research has shown that awareness of stigma is associated with reduced self-esteem among people with mental illness. No prior studies have examined the association between self-esteem and stereotype awareness among individuals with past suicide attempts. Aims: To understand the relationship between stereotype awareness and self-esteem among young adults who have and have not attempted suicide. Method: Computerized surveys were administered to college students (N = 637). Linear regression analyses were used to test associations between self-esteem and stereotype awareness, attempt history, and their interaction. Results: There was a significant stereotype awareness by attempt interaction (β = –.74, p = .006) in the regression analysis. The interaction was explained by a stronger negative association between stereotype awareness and self-esteem among individuals with past suicide attempts (β = –.50, p = .013) compared with those without attempts (β = –.09, p = .037). Conclusion: Stigma is associated with lower self-esteem within this high-functioning sample of young adults with histories of suicide attempts. Alleviating the impact of stigma at the individual (clinical) or community (public health) levels may improve self-esteem among this high-risk population, which could potentially influence subsequent suicide risk.


2010 ◽  
Vol 15 (4) ◽  
pp. 304-311 ◽  
Author(s):  
Christopher J. Ferguson ◽  
Amanda M. Cruz ◽  
Daniel Martinez ◽  
Stephanie M. Rueda ◽  
Diana E. Ferguson

Despite several studies investigating the impact of sex and violence in television on consumer behavior and memory for products in commercials, results remain inconsistent and debated. The purpose of the current study was to examine the effects of television violence and sex on memory for commercials and willingness to buy products. Two hundred twelve young adults were assigned to watch either a sexual, violent, combined sexual and violent or neutral television show. Within each show were embedded 12 commercials, four violent, four sexual, and four neutral. Results indicated that violent or sexual content of the television show did not impair memory for commercials or willingness to buy products, and that sexual or violent content in the commercials themselves increased memory for those commercials. Implications for the current study are that violent or sexual shows may adequately function in attracting viewers’ attention, with sexual and violent content in the commercials themselves improving viewers memory for products. Use of violent or sexual content in commercials may thus be useful in advertising for brand recall.


2019 ◽  
Vol 131 (6) ◽  
pp. 1920-1925
Author(s):  
Daniel A. Tonetti ◽  
William J. Ares ◽  
David O. Okonkwo ◽  
Paul A. Gardner

OBJECTIVELarge interhemispheric subdural hematomas (iSDHs) causing falx syndrome are rare; therefore, a paucity of data exists regarding the outcomes of contemporary management of iSDH. There is a general consensus among neurosurgeons that large iSDHs with neurological deficits represent a particular treatment challenge with generally poor outcomes. Thus, radiological and clinical outcomes of surgical and nonsurgical management for iSDH bear further study, which is the aim of this report.METHODSA prospectively collected, single-institution trauma database was searched for patients with isolated traumatic iSDH causing falx syndrome in the period from January 2008 to January 2018. Information on demographic and radiological characteristics, serial neurological examinations, clinical and radiological outcomes, and posttreatment complications was collected and tallied. The authors subsequently dichotomized patients by management strategy to evaluate clinical outcome and 30-day survival.RESULTSTwenty-five patients (0.4% of those with intracranial injuries, 0.05% of those with trauma) with iSDH and falx syndrome represented the study cohort. The average age was 73.4 years, and most patients (23 [92%] of 25) were taking anticoagulants or antiplatelet medications. Six patients were managed nonoperatively, and 19 patients underwent craniotomy for iSDH evacuation; of the latter patients, 17 (89.5%) had improvement in or resolution of motor deficits postoperatively. There were no instances of venous infarction, reaccumulation, or infection after evacuation. In total, 9 (36%) of the 25 patients died within 30 days, including 6 (32%) of the 19 who had undergone craniotomy and 3 (50%) of the 6 who had been managed nonoperatively. Patients who died within 30 days were significantly more likely to experience in-hospital neurological deterioration prior to surgery (83% vs 15%, p = 0.0095) and to be comatose prior to surgery (100% vs 23%, p = 0.0031). The median modified Rankin Scale score of surgical patients who survived hospitalization (13 patients) was 1 at a mean follow-up of 22.1 months.CONCLUSIONSiSDHs associated with falx syndrome can be evacuated safely and effectively, and prompt surgical evacuation prior to neurological deterioration can improve outcomes. In this study, craniotomy for iSDH evacuation proved to be a low-risk strategy that was associated with generally good outcomes, though appropriately selected patients may fare well without evacuation.


2008 ◽  
Vol 1 (4) ◽  
pp. A353
Author(s):  
Shenandoah Robinson ◽  
Qing Li

Introduction Many infants born very preterm who suffer brain damage most likely experienced a combined insult from intrauterine infection and placental insufficiency. Damage is thought to be synergistic rather than additive but the mechanisms of combined injury remain elusive. A combination of lipopolysaccharide-induced inflammation and hypoxia-ischemia has been used in rats to model the dual insult that occurs in human infants prenatally. Erythropoietin, a pleiotrophic cytokine that is essential for central nervous system development, ameliorates brain injury after isolated hypoxic-ischemic or inflammatory insults through different intracellular signaling pathways. We hypothesized that exogenous neonatal EPO administration would lessen the damage of a combined prenatal insult in rats. Methods On embryonic Day 18 fetal rats experienced 60 minutes of transient uterine artery occlusion with or without intracervical LPS administration with sham controls receiving surgery but no occlusion and saline for LPS. Survival was recorded and histological biochemical and functional assays were performed. Means were compared with ANOVA with Tukey HSD post hoc analysis. Results After a combined insult of HI and 0.15-mg/kg LPS on E18 the survival of pups by postnatal Day 1 (P1) decreased from 77% with HI alone to 22% for LPS plus HI. When exogenous systemic EPO was administered P1–P3 survival to P9 improved markedly from 40% (2 of 5) for saline-treated insult pups to 100% (6 of 6) for EPO-treated. Initial histological analyses show EPO decreases the number of brain activated caspase 3 and activated microglia by P9. Additional analyses will be presented. Conclusion As at least 60% of placentas from infants born pre-term show evidence of chorioamnionitis, assessment of the impact of exogenous EPO on a model of a combination injury is essential prior to proceeding with a clinical trial. Initial results indicate neonatal exogenous EPO mitigates damage from the combined insult.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Nathaniel B. Bone ◽  
Eugene J. Becker ◽  
Maroof Husain ◽  
Shaoning Jiang ◽  
Anna A. Zmijewska ◽  
...  

AbstractMetabolic and bioenergetic plasticity of immune cells is essential for optimal responses to bacterial infections. AMPK and Parkin ubiquitin ligase are known to regulate mitochondrial quality control mitophagy that prevents unwanted inflammatory responses. However, it is not known if this evolutionarily conserved mechanism has been coopted by the host immune defense to eradicate bacterial pathogens and influence post-sepsis immunosuppression. Parkin, AMPK levels, and the effects of AMPK activators were investigated in human leukocytes from sepsis survivors as well as wild type and Park2−/− murine macrophages. In vivo, the impact of AMPK and Parkin was determined in mice subjected to polymicrobial intra-abdominal sepsis and secondary lung bacterial infections. Mice were treated with metformin during established immunosuppression. We showed that bacteria and mitochondria share mechanisms of autophagic killing/clearance triggered by sentinel events that involve depolarization of mitochondria and recruitment of Parkin in macrophages. Parkin-deficient mice/macrophages fail to form phagolysosomes and kill bacteria. This impairment of host defense is seen in the context of sepsis-induced immunosuppression with decreased levels of Parkin. AMPK activators, including metformin, stimulate Parkin-independent autophagy and bacterial killing in leukocytes from post-shock patients and in lungs of sepsis-immunosuppressed mice. Our results support a dual role of Parkin and AMPK in the clearance of dysfunctional mitochondria and killing of pathogenic bacteria, and explain the immunosuppressive phenotype associated Parkin and AMPK deficiency. AMPK activation appeared to be a crucial therapeutic target for the macrophage immunosuppressive phenotype and to reduce severity of secondary bacterial lung infections and respiratory failure.


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