scholarly journals Intradialytic Cerebral Hypoperfusion as Mechanism for Cognitive Impairment in Patients on Hemodialysis

2019 ◽  
Vol 30 (11) ◽  
pp. 2052-2058 ◽  
Author(s):  
Dawn F. Wolfgram
Keyword(s):  
Cognitive Impairment ◽  
Cerebral Perfusion ◽  
Ischemic Injury ◽  
Hemodialysis Patients ◽  
Cognitive Outcomes ◽  
Cerebral Injury ◽  
Cerebral Hypoperfusion ◽  
Increased Risk ◽  
Cerebral Ischemic Injury ◽  
Cerebral Ischemic

The high frequency of cognitive impairment in individuals on hemodialysis is well characterized. In-center hemodialysis patients are disproportionately affected by cognitive impairment compared with other dialysis populations, identifying hemodialysis itself as a possible factor. The pathophysiology of cognitive impairment has multiple components, but vascular-mediated cerebral injury appears to contribute based on studies demonstrating increased cerebral ischemic lesions and atrophy in brain imaging of patients on hemodialysis. Patients on hemodialysis may be at increased risk for cerebral ischemic injury disease due to vasculopathy associated with ESKD and from their comorbid diseases, such as hypertension and diabetes. This review focuses on the intradialytic cerebral hypoperfusion that can occur during routine hemodialysis due to the circulatory stress of hemodialysis. This includes a review of current methods used to monitor intradialytic cerebral perfusion and the structural and functional cognitive outcomes that have been associated with changes in intradialytic cerebral perfusion. Monitoring of intradialytic cerebral perfusion may become clinically relevant as nephrologists try to avoid the cognitive complications seen with hemodialysis. Identifying the appropriate methods to assess risk for cerebral ischemic injury and the relationship of intradialytic cerebral hypoperfusion to cognitive outcomes will help inform the decision to use intradialytic cerebral perfusion monitoring in the clinical setting as part of a strategy to prevent cognitive decline.

scholarly journals PGE2 signaling via the neuronal EP2 receptor increases injury in a model of cerebral ischemia

2019 ◽  
Vol 116 (20) ◽  
pp. 10019-10024 ◽  
Author(s):  
Qingkun Liu ◽  
Xibin Liang ◽  
Qian Wang ◽  
Edward N. Wilson ◽  
Rachel Lam ◽  
...  
Keyword(s):  
Ischemic Injury ◽  
Myeloid Cell ◽  
Cell Types ◽  
Receptor Expression ◽  
Cerebral Injury ◽  
Stroke Severity ◽  
Cell Trafficking ◽  
Cerebral Ischemic Injury ◽  
Cerebral Ischemic ◽  
Ep2 Receptor

The inflammatory prostaglandin E2 (PGE2) EP2 receptor is a master suppressor of beneficial microglial function, and myeloid EP2 signaling ablation reduces pathology in models of inflammatory neurodegeneration. Here, we investigated the role of PGE2 EP2 signaling in a model of stroke in which the initial cerebral ischemic event is followed by an extended poststroke inflammatory response. Myeloid lineage cell-specific EP2 knockdown in Cd11bCre;EP2lox/lox mice attenuated brain infiltration of Cd11b+CD45hi macrophages and CD45+Ly6Ghi neutrophils, indicating that inflammatory EP2 signaling participates in the poststroke immune response. Inducible global deletion of the EP2 receptor in adult ROSA26-CreERT2 (ROSACreER);EP2lox/lox mice also reduced brain myeloid cell trafficking but additionally reduced stroke severity, suggesting that nonimmune EP2 receptor-expressing cell types contribute to cerebral injury. EP2 receptor expression was highly induced in neurons in the ischemic hemisphere, and postnatal deletion of the neuronal EP2 receptor in Thy1Cre;EP2lox/lox mice reduced cerebral ischemic injury. These findings diverge from previous studies of congenitally null EP2 receptor mice where a global deletion increases cerebral ischemic injury. Moreover, ROSACreER;EP2lox/lox mice, unlike EP2−/− mice, exhibited normal learning and memory, suggesting a confounding effect from congenital EP2 receptor deletion. Taken together with a precedent that inhibition of EP2 signaling is protective in inflammatory neurodegeneration, these data lend support to translational approaches targeting the EP2 receptor to reduce inflammation and neuronal injury that occur after stroke.

scholarly journals Oxidative Stress, Inflammation, and Autophagy: Potential Targets of Mesenchymal Stem Cells-Based Therapies in Ischemic Stroke

2021 ◽  
Vol 15 ◽  
Author(s):  
Jialin He ◽  
Jianyang Liu ◽  
Yan Huang ◽  
Xiangqi Tang ◽  
Han Xiao ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Stem Cells ◽  
Blood Flow ◽  
Mesenchymal Stem Cells ◽  
Ischemic Stroke ◽  
Ischemic Injury ◽  
Cerebral Injury ◽  
Inflammatory Activity ◽  
Cerebral Ischemic Injury ◽  
Cerebral Ischemic

Ischemic stroke is a leading cause of death worldwide; currently available treatment approaches for ischemic stroke are to restore blood flow, which reduce disability but are time limited. The interruption of blood flow in ischemic stroke contributes to intricate pathophysiological processes. Oxidative stress and inflammatory activity are two early events in the cascade of cerebral ischemic injury. These two factors are reciprocal causation and directly trigger the development of autophagy. Appropriate autophagy activity contributes to brain recovery by reducing oxidative stress and inflammatory activity, while autophagy dysfunction aggravates cerebral injury. Abundant evidence demonstrates the beneficial impact of mesenchymal stem cells (MSCs) and secretome on cerebral ischemic injury. MSCs reduce oxidative stress through suppressing reactive oxygen species (ROS) and reactive nitrogen species (RNS) generation and transferring healthy mitochondria to damaged cells. Meanwhile, MSCs exert anti-inflammation properties by the production of cytokines and extracellular vesicles, inhibiting proinflammatory cytokines and inflammatory cells activation, suppressing pyroptosis, and alleviating blood–brain barrier leakage. Additionally, MSCs regulation of autophagy imbalances gives rise to neuroprotection against cerebral ischemic injury. Altogether, MSCs have been a promising candidate for the treatment of ischemic stroke due to their pleiotropic effect.

scholarly journals Effects of Etanercept against Transient Cerebral Ischemia in Diabetic Rats

2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Naohiro Iwata ◽  
Hiroko Takayama ◽  
Meiyan Xuan ◽  
Shinya Kamiuchi ◽  
Hirokazu Matsuzaki ◽  
...  
Keyword(s):  
Cerebral Ischemia ◽  
Ischemic Injury ◽  
Repeated Administration ◽  
Diabetic Rats ◽  
Transient Cerebral Ischemia ◽  
Cerebral Injury ◽  
Cerebral Damage ◽  
Diabetic State ◽  
Cerebral Ischemic Injury ◽  
Cerebral Ischemic

Diabetes mellitus is known to exacerbate acute cerebral ischemic injury. Previous studies have demonstrated that infarction volumes caused by transient cerebral ischemia were greater in diabetic rats than in nondiabetic rats. Tumor necrosis factor-α(TNF-α) is a proinflammatory protein produced in the brain in response to cerebral ischemia that promotes apoptosis. Etanercept (ETN), a recombinant TNF receptor (p75)-Fc fusion protein, competitively inhibits TNF-α. Therefore, we evaluated the neuroprotective effects of chronic or acute treatment with ETN on cerebral injury caused by middle cerebral artery occlusion/reperfusion (MCAO/Re) in rats with streptozotocin-induced diabetes. Furthermore, we evaluated the effects of ETN against the apoptosis and myeloperoxidase activity. Single administration of ETN before MCAO significantly suppressed exacerbation of cerebral damage in nondiabetic rats, as assessed by infarct volume. In contrast, the diabetic state markedly aggravated MCAO/Re-induced cerebral damage despite ETN treatment within 24 h before MCAO. However, the damage was improved by repeated administration of ETN at 900 μg/kg/daily in rats in an induced diabetic state. These results suggested that repeated administration of ETN can prevent exacerbation of cerebral ischemic injury in the diabetic state and is mainly attributed to anti-inflammatory effects.

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