Rotavirus hospitalization in early childhood: fine motor skills and cognition at six years old-Population-based cohort study.

Rotavirus is linked to severe childhood gastroenteritis and neurological complications, but its impact on neurodevelopment remains uncertain. We examined data from 1,420,941 Korean children born between 2009 and 2011, using the Korean National Health Insurance System. At age 6, we assessed neurodevelopmental outcomes using the validated Korean Developmental Test, covering six major domains. Utilizing propensity score-based Inverse Probability Weighting to ensure covariates including considering covariates including sex, birth weight, changes in body weight from birth to 4-6 months of age, head circumference at 4-6 months of age, residence at birth, economic status, infant feeding types, and birth year. The main analysis that encompassed 5,451 children with rotavirus hospitalization and 310,874 unexposed individuals reveled heightened odds of suspected delays in fine motor skills and cognition among exposed children. Our results suggest an association between rotavirus-related hospitalization in infancy and suspected delays in fine motor function and cognition in 6-year-olds.

Selective TLR4 Antagonism Prevents and Reverses Morphine-Induced Persistent Postoperative Cognitive Dysfunction, Dysregulation of Synaptic Elements, and Impaired BDNF Signaling in Aged Male Rats.

Perioperative neurocognitive disorders (PNDs) are characterized by confusion, difficulty with executive function, and episodic memory impairment in the hours to months following a surgical procedure. Postoperative cognitive dysfunction (POCD) represents such impairments that last beyond 30 d postsurgery and is associated with increased risk of comorbidities, progression to dementia, and higher mortality. While it is clear that neuroinflammation plays a key role in PND development, what factors underlie shorter self-resolving versus persistent PNDs remains unclear. We have previously shown that postoperative morphine treatment extends POCD from 4 d (without morphine) to at least 8 weeks (with morphine) in aged male rats, and that this effect is likely dependent on the proinflammatory capabilities of morphine via activation of toll-like receptor 4 (TLR4). Here, we extend these findings to show that TLR4 blockade, using the selective TLR4 antagonist lipopolysaccharide from the bacterium Rhodobacter sphaeroides (LPS-RS Ultrapure), ameliorates morphine-induced POCD in aged male rats. Using either a single central preoperative treatment or a 1 week postoperative central treatment regimen, we demonstrate that TLR4 antagonism (1) prevents and reverses the long-term memory impairment associated with surgery and morphine treatment, (2) ameliorates morphine-induced dysregulation of the postsynaptic proteins postsynaptic density 95 and synaptopodin, (3) mitigates reductions in mature BDNF, and (4) prevents decreased activation of the BDNF receptor TrkB (tropomyosin-related kinase B), all at 4 weeks postsurgery. We also reveal that LPS-RS Ultrapure likely exerts its beneficial effects by preventing endogenous danger signal HMGB1 (high-mobility group box 1) from activating TLR4, rather than by blocking continuous activation by morphine or its metabolites. These findings suggest TLR4 as a promising therapeutic target to prevent or treat PNDs.SIGNIFICANCE STATEMENT With humans living longer than ever, it is crucial that we identify mechanisms that contribute to aging-related vulnerability to cognitive impairment. Here, we show that the innate immune receptor toll-like receptor 4 (TLR4) is a key mediator of cognitive dysfunction in aged rodents following surgery and postoperative morphine treatment. Inhibition of TLR4 both prevented and reversed surgery plus morphine-associated memory impairment, dysregulation of synaptic elements, and reduced BDNF signaling. Together, these findings implicate TLR4 in the development of postoperative cognitive dysfunction, providing mechanistic insight and novel therapeutic targets for the treatment of cognitive impairments following immune challenges such as surgery in older individuals.

Impaired cortical neuronal homeostasis and cognition after diffuse traumatic brain injury are dependent on microglia and type I interferon responses.

Neuropsychiatric complications including depression and cognitive decline develop in the years after traumatic brain injury (TBI), negatively affecting quality of life. Microglial and type 1 interferon (IFN-I) responses are associated with the transition from acute to chronic neuroinflammation after diffuse TBI in mice. Thus, the purpose of this study was to determine if impaired neuronal homeostasis and increased IFN-I responses intersected after TBI to cause cognitive impairment. Here, the RNA profile of neurons and microglia after TBI (single nucleus RNA-sequencing) with or without microglia depletion (CSF1R antagonist) was assessed 7 dpi. There was a TBI-dependent suppression of cortical neuronal homeostasis with reductions in CREB signaling, synaptogenesis, and synaptic migration and increases in RhoGDI and PTEN signaling (Ingenuity Pathway Analysis). Microglial depletion reversed 50% of TBI-induced gene changes in cortical neurons depending on subtype. Moreover, the microglial RNA signature 7 dpi was associated with increased stimulator of interferon genes (STING) activation and IFN-I responses. Therefore, we sought to reduce IFN-I signaling after TBI using STING knockout mice and a STING antagonist, chloroquine (CQ). TBI-associated cognitive deficits in novel object location and recognition (NOL/NOR) tasks at 7 and 30 dpi were STING dependent. In addition, TBI-induced STING expression, microglial morphological restructuring, inflammatory (Tnf, Cd68, Ccl2) and IFN-related (Irf3, Irf7, Ifi27) gene expression in the cortex were attenuated in STINGKO mice. CQ also reversed TBI-induced cognitive deficits and reduced TBI-induced inflammatory (Tnf, Cd68, Ccl2) and IFN (Irf7, Sting) cortical gene expression. Collectively, reducing IFN-I signaling after TBI with STING-dependent interventions attenuated the prolonged microglial activation and cognitive impairment.

Prestroke Cognitive Impairment: Frequency and Association With Premorbid Neuropsychiatric, Functional, and Neuroimaging Features.

BACKGROUND: Some patients with stroke have prestroke cognitive impairment (pre-SCI), but its etiology is not clear. The aim of this cross-sectional study was to assess the frequency of pre-SCI and its association with premorbid neuropsychiatric, functional, and neuroimaging features. METHODS: Patients hospitalized in stroke unit with an informant who could complete IQCODE (Informant Questionnaire for Cognitive Decline in the Elderly) were included. Pre-SCI was diagnosed if the IQCODE score was >3.3. Prestroke assessment also included NPI-Q (Neuropsychiatric Inventory Questionnaire), the basic Activities of Daily Living and Instrumental Activities of Daily Living scales, and the Clinical Dementia Rating scale. A multivariate logistic regression model was used to evaluate the association of pre-SCI with age, sex, education, arterial hypertension, atrial fibrillation, white matter lesions, cerebral microbleeds, and pathological medial temporal lobe atrophy. RESULTS: IQCODE was available in 474 of 520 patients (91.2%; 45% women; mean age 75.5±13.3 years). Pre-SCI had a prevalence of 32.5% and was associated with prestroke NPI-Q (pre-SCI absent versus present, 1.7±2.3 versus 5.5±4.9; P<0.001), Activities of Daily Living scale (0.3±0.8 versus 1.8±1.9; P<0.001), Instrumental Activities of Daily Living scale (0.6±1.3 versus 3.8±4.0; P<0.001), and Clinical Dementia Rating scale score (0.7±1.7 versus 7.2±6.2; P<0.001). In the 271 patients with a magnetic resonance imaging available, the multivariate logistic regression showed that age (odds ratio [OR], 1.05 [95% CI, 1.62-9.73]), white matter lesions (OR, 1.26 [95% CI, 1.003-1.58]), and a pathological medial temporal lobe atrophy score (OR, 3.97 [95% CI, 1.62-9.73]) were independently associated with pre-SCI. In the 218 patients with ischemic stroke, white matter lesions (OR, 1.34 [95% CI, 1.04-1.72]) and medial temporal lobe atrophy (OR, 3.56 [95% CI, 1.38-9.19]), but not age, were associated with pre-SCI. CONCLUSIONS: One-third of patients admitted to a stroke unit have pre-SCI that is associated with preexisting neuropsychiatric symptoms and functional performance. White matter lesions and medial temporal lobe atrophy are associated with pre-SCI, suggesting that both small vessel disease and neurodegeneration might be involved in its etiology.

Relationship of Perivascular Space Markers With Incident Dementia in Cerebral Small Vessel Disease.

BACKGROUND: Recent studies, using diffusion tensor image analysis along the perivascular space (DTI-ALPS), suggest impaired perivascular space (PVS) function in cerebral small vessel disease, but they were cross-sectional, making inferences on causality difficult. We determined associations between impaired PVS, measured using DTI-ALPS and PVS volume, and cognition and incident dementia. METHODS: In patients with lacunar stroke and confluent white matter hyperintensities, without dementia at baseline, recruited prospectively in a single center, magnetic resonance imaging was performed annually for 3 years, and cognitive assessments, including global, memory, executive function, and processing speed, were performed annually for 5 years. We determined associations between DTI-ALPS and PVS volume with cerebral small vessel disease imaging markers (white matter hyperintensity volume, lacunes, and microbleeds) at baseline and with changes in imaging markers. We determined whether DTI-ALPS and PVS volume at baseline and change over 3 years predicted incident dementia. Analyses were controlled for conventional diffusion tensor image metrics using 2 markers (median mean diffusivity [MD] and peak width of skeletonized MD) and adjusted for age, sex, and vascular risk factors. RESULTS: A total of 120 patients, mean age 70.0 years and 65.0% male, were included. DTI-ALPS declined over 3 years, while no change in PVS volume was found. Neither DTI-ALPS nor PVS volume was associated with cerebral small vessel disease imaging marker progression. Baseline DTI-ALPS was associated with changes in global cognition (ß=0.142, P=0.032), executive function (ß=0.287, P=0.027), and long-term memory (ß=0.228, P=0.027). Higher DTI-ALPS at baseline predicted a lower risk of dementia (hazard ratio, 0.328 [0.183-0.588]; P<0.001), and this remained significant after including median MD as a covariate (hazard ratio, 0.290 [0.139-0.602]; P<0.001). Change in DTI-ALPS predicted dementia conversion (hazard ratio, 0.630 [0.428-0.964]; P=0.048), but when peak width of skeletonized MD and median MD were entered as covariates, the association was not significant. There was no association between baseline PVS volume, or PVS change over 3 years, and conversion to dementia. CONCLUSIONS: DTI-ALPS predicts future dementia risk in patients with lacunar strokes and confluent white matter hyperintensities. However, the weakening of the association between change in DTI-ALPS and incident dementia after controlling for peak width of skeletonized MD and median MD suggests part of the signal may represent conventional diffusion tensor image metrics. PVS volume is not a predictor of future dementia risk.

Diagnostic Accuracy of Posterior/Anterior Periventricular WMH Ratio to Differentiate CAA From Hypertensive Arteriopathy.

BACKGROUND: Periventricular white matter hyperintensities (PVWMHs) in cerebral amyloid angiopathy (CAA) have been reported posterior predominant using semiautomated segmentation method and logarithmic transformation. We aimed to compare PVWMH extent and posterior/anterior distribution between patients with CAA and patients with hypertensive arteriopathy with radiological tools available in daily practice. METHODS: We retrospectively analyzed confluent PVWMH directly adjacent to lateral ventricles on axial FLAIR (fluid-attenuated inversion recovery) from 108 patients with CAA and 99 patients with hypertensive arteriopathy presenting with hemorrhage-related symptoms consecutively recruited in our stroke database (Nîmes University Hospital, France) between January 2015 and March 2022. For each of the left (L), right (R), anterior (A), and posterior (P) horns of lateral ventricles, the maximal distance between the outer PVWMH border and ventricle border was measured. The sum of anterior left PVWMH and anterior right PVWMH, and posterior left PVWMH and posterior right PVWMH resulted in anterior and posterior extent, respectively. RESULTS: Compared with hypertensive arteriopathy, patients with CAA were older (median, 77 versus 71; P=0.0010) and less frequently male (46% versus 64%; P=0.012) and had less frequent hypertension (45% versus 63%; P=0.013) and more chronic hemorrhages (P<0.0001). CAA showed slightly more extensive anterior right PVWMH (median, 6.50 versus 5.90 mm; P=0.034), far more extensive (all P<0.0001) posterior left PVWMH (median, 13.95 versus 6.95 mm), posterior right PVWMH (median, 14.15 versus 5.45 mm), posterior (median, 27.95 versus 13.00 mm), and total (median, 39.60 versus 24.65 mm) PVWMH, and higher posterior/anterior ratios (median, 1.82 versus 1.01). Age-/sex-adjusted model predicting CAA incorporating total PVWMH extent and posterior/anterior ratios for the given score (-4.3683+0.0268×PVWMH-T+0.3749×posterior/anterior PVWMH ratio+0.0394×age+0.3046 when female) showed highest area under the curve (0.76 [0.70-0.83]), with a 72% [62.50-80.99] sensitivity and 76% [67.18-84.12] specificity. Values above the optimal threshold of 0.22 for the score showed a crude relative risk of 2.75 (2.26-2.37; P<0.0001). CONCLUSIONS: Severe posterior PVWMH and high posterior/anterior PVWMH ratio assessed by radiological tools used in daily practice are associated with probable CAA versus hypertensive arteriopathy. REGISTRATION: URL: https://www.clinicaltrials.gov; Unique identifier: NCT05486897.

Prevention of Vascular Contributions to Cognitive Impairment and Dementia: The Role of Physical Activity and Exercise.

Vascular contributions to cognitive impairment and dementia, specifically cerebral small vessel disease (CSVD), are the second most common cause of dementia. Currently, there are no specific pharmacological treatments for CSVD, and the use of conventional antidementia drugs is not recommended. Exercise has the potential to prevent and mitigate CSVD-related brain damage and improve cognitive function. Mechanistic pathways underlying the neurocognitive benefits of exercise include the control of vascular risk factors, improving endothelial function, and upregulating exerkines. Notably, the therapeutic efficacy of exercise may vary by exercise type (ie, aerobic versus resistance training) and biological sex; thus, studies designed specifically to examine these moderating factors within a CSVD context are needed. Furthermore, future research should prioritize resistance training interventions, given their tremendous therapeutic potential. Addressing these knowledge gaps will help us refine exercise recommendations to maximize their therapeutic impact in the prevention and mitigation of CSVD.

Cardiovascular Management in Asymptomatic (Silent) Cerebral Microbleeds and Suspected Cerebral Amyloid Angiopathy.

Cerebral microbleeds (CMBs) detected on blood-sensitive magnetic resonance imaging sequences are usually a sign of an underlying cerebral small vessel disease such as sporadic cerebral amyloid angiopathy or sporadic nonamyloid small vessel pathology (eg, arteriolosclerosis). Much of the enduring interest in CMBs relates to their high prevalence (partly due to the widespread use of magnetic resonance imaging) in the context of stroke, cognitive impairment and in healthy individuals, and the clinical uncertainties created about the safety of antithrombotic medications due to their association with both future hemorrhagic and ischemic stroke. Historically, the research literature overwhelmingly emphasized the future hemorrhagic risk associated with CMBs, potentially leading to unnecessary withholding of treatments proven effective at preventing thrombosis, such as anticoagulants in patients with atrial fibrillation who happened to have some microbleeds. The lack of strong guidelines in this area contributes to wide variation in clinical practice. In this article, we critically review and discuss the implications of silent CMBs and cortical superficial siderosis (ie, without symptomatic intracerebral hemorrhage) in different clinical settings: the general population, patients with ischemic stroke, and the memory clinic. Emerging evidence, albeit not from randomized controlled trials, suggests that in most patients, CMBs alone should not prevent the use of antithrombotics or anticoagulants for stroke prevention, when they are otherwise indicated. Where possible, we provide specific suggestions for clinical care grounded in both the limited available literature and our personal clinical practice.

Dl-3-n-Butylphthalide Alleviates Secondary Brain Damage and Improves Working Memory After Stroke in Cynomolgus Monkeys.

BACKGROUND: Remote secondary neurodegeneration is associated with poststroke cognitive impairment (PSCI). Dl-3-n-butylphthalide (NBP) improves PSCI clinically. However, whether it ameliorates PSCI by alleviating secondary neurodegeneration remains uncertain. Nonhuman primates provide more relevant models than rodents for human stroke and PSCI. This study investigated the effects of NBP on PSCI and secondary neurodegeneration in cynomolgus monkeys after permanent left middle cerebral artery occlusion (MCAO). METHODS: Thirteen adult male cynomolgus monkeys were randomly assigned to sham (n=4), MCAO+placebo (n=5), and MCAO+NBP groups (n=4). The MCAO+placebo and MCAO+NBP groups received saline and NBP injections intravenously, respectively, starting at 6-hour postsurgery for 2 weeks, followed by soybean oil and NBP orally, respectively, for 10 weeks after MCAO. Infarct size was assessed at week 4 by magnetic resonance imaging. Working memory and executive function were evaluated dynamically using the delayed response task and object retrieval detour task, respectively. Neuron loss, glia proliferation, and neuroinflammation in the ipsilateral dorsal lateral prefrontal cortex, thalamus, and hippocampus were analyzed by immunostaining 12 weeks after MCAO. RESULTS: Infarcts were located in the left middle cerebral artery region, apart from the ipsilateral dorsal lateral prefrontal cortex, thalamus, or hippocampus, with no significant difference between the MCAO+placebo and MCAO+NBP group. Higher success in delayed response task was achieved at weeks 4, 8, and 12 after NBP compared with placebo treatments (P<0.05), but not in the object retrieval detour task (all P>0.05). More neurons and less microglia, astrocytes, CD68-positive microglia, tumor necrosis factor-α, and inducible NO synthase were observed in the ipsilateral dorsal lateral prefrontal cortex and thalamus after 12 weeks of NBP treatment (P<0.05), but not in the hippocampus (P>0.05). CONCLUSIONS: Our findings indicate that NBP improves working memory by alleviating remote secondary neurodegeneration and neuroinflammation in the ipsilateral dorsal lateral prefrontal cortex and thalamus after MCAO in cynomolgus monkeys.

Dexmedetomidine alleviates hippocampal neuronal loss and cognitive decline in rats undergoing open surgery under sevoflurane anaesthesia by suppressing CCAAT/enhancer-binding protein beta.

Dexmedetomidine (Dex) may exert neuroprotective effects by attenuating inflammatory responses. However, whether Dex specifically improves postoperative cognitive dysfunction (POCD) by inhibiting microglial inflammation through what pathway remains unclear. In this study, the POCD model was constructed by performing open surgery after 3 h of continuous inhalation of 3% sevoflurane to rats, which were intraperitoneally injected with 25 µg/kg Dex .5 h before anaesthesia. The results displayed that Dex intervention decreased rat escape latency, maintained swimming speed and increased the number of times rats crossed the platform and the time spent in the target quadrant. Furthermore, the rat neuronal injury was restored, alleviated POCD modelling-induced rat hippocampal microglial activation and inhibited microglial M1 type polarization. Besides, we administered Dex injection and/or CCAAT/enhancer-binding protein beta (CEBPB) knockdown on the basis of sevoflurane exposure and open surgery and found that CEBPB was knocked down, resulting in the inability of Dex to function, which confirmed CEBPB as a target for Dex treatment. To sum up, Dex improved POCD by considering CEBPB as a drug target to activate the c-Jun N-terminal kinase (JNK)/p-38 signaling pathway, inhibiting microglial M1 polarization-mediated inflammation in the central nervous system.

Overexpression of SESN1 improves mitochondrial damage and mitophagy, a potential therapeutic strategy for cognitive dysfunction after anaesthesia.

Postoperative cognitive dysfunction (POCD) is a prevalent central nervous system complication predominantly observed in elderly patients. Sevoflurane, a general anaesthetic agent, has been implicated in the development of POCD, yet the underlying regulatory mechanisms potentially involving Sestrin1 (SESN1), a stress-responsive protein that plays a critical role in cellular homeostasis and protection against stress-induced damage, including oxidative stress and DNA damage, remain elusive. This study endeavoured to elucidate the impact of SESN1 on sevoflurane-induced cognitive impairment in rats. Employing a model in which SESN1 was transfected into SD male rats and cognitive dysfunction was induced by sevoflurane. The Morris Water Maze test was used for behavioural evaluation, Enzyme-Linked Immunosorbent Assay, Western blotting and immunofluorescence were applied to assess the influence of SESN1 on the inflammatory response and mitophagy in the rat hippocampus. The study further aimed to uncover the putative mechanism by which SESN1, through SIRT1, might modulate cognitive function. Concurrently, levels of malondialdehyde, superoxide dismutase and mitochondrially produced ATP within the rat hippocampus were quantified. Experimental outcomes suggested that SESN1 overexpression significantly mitigated the deleterious effects of sevoflurane anaesthesia, ameliorated neuroinflammation and inflammasome activation, modified mitochondrial function and facilitated mitophagy. Additionally, SESN1, via the activation of SIRT1, may suppress inflammasome activation and mitochondrial dysfunction. Collectively, these findings underscore SESN1's integral role in counteracting sevoflurane-induced cognitive impairment, impeding inflammasome activation, enhancing mitochondrial function and fostering mitophagy, which appear to be intricately linked to SESN1-mediated SIRT1 activation. SESN1 is a novel therapeutic target for POCD, potentially advancing neuroprotective strategies in clinical settings.

An exploratory research report on brain mineralization in postoperative delirium and cognitive decline.

Delirium is a severe postoperative complication associated with poor overall and especially neurocognitive prognosis. Altered brain mineralization is found in neurodegenerative disorders but has not been studied in postoperative delirium and postoperative cognitive decline. We hypothesized that mineralization-related hypointensity in susceptibility-weighted magnetic resonance imaging (SWI) is associated with postoperative delirium and cognitive decline. In an exploratory, hypothesis-generating study, we analysed a subsample of cognitively healthy patients ≥65 years who underwent SWI before (N = 65) and 3 months after surgery (N = 33). We measured relative SWI intensities in the basal ganglia, hippocampus and posterior basal forebrain cholinergic system (pBFCS). A post hoc analysis of two pBFCS subregions (Ch4, Ch4p) was conducted. Patients were screened for delirium until the seventh postoperative day. Cognitive testing was performed before and 3 months after surgery. Fourteen patients developed delirium. After adjustment for age, sex, preoperative cognition and region volume, only pBFCS hypointensity was associated with delirium (regression coefficient [90% CI]: B = -15.3 [-31.6; -0.8]). After adjustments for surgery duration, age, sex and region volume, perioperative change in relative SWI intensities of the pBFCS was associated with cognitive decline 3 months after surgery at a trend level (B = 6.8 [-0.9; 14.1]), which was probably driven by a stronger association in subregion Ch4p (B = 9.3 [2.3; 16.2]). Brain mineralization, particularly in the cerebral cholinergic system, could be a pathomechanism in postoperative delirium and cognitive decline. Evidence from our studies is limited because of the small sample and a SWI dataset unfit for iron quantification, and the analyses presented here should be considered exploratory.

Protecting effects of 4-octyl itaconate on neonatal hypoxic-ischemic encephalopathy via Nrf2 pathway in astrocytes.

BACKGROUND: Neonatal hypoxic-ischemic encephalopathy (HIE) is one of the most common neurological problems occurring in the perinatal period. However, there still is not a promising approach to reduce long-term neurodevelopmental outcomes of HIE. Recently, itaconate has been found to exhibit anti-oxidative and anti-inflammatory effects. However, the therapeutic efficacy of itaconate in HIE remains inconclusive. Therefore, this study attempts to explore the pathophysiological mechanisms of oxidative stress and inflammatory responses in HIE as well as the potential therapeutic role of a derivative of itaconate, 4-octyl itaconate (4OI). METHODS: We used 7-day-old mice to induce hypoxic-ischemic (HI) model by right common carotid artery ligation followed by 1 h of hypoxia. Behavioral experiments including the Y-maze and novel object recognition test were performed on HI mice at P60 to evaluate long-term neurodevelopmental outcomes. We employed an approach combining non-targeted metabolomics with transcriptomics to screen alterations in metabolic profiles and gene expression in the hippocampal tissue of the mice at 8 h after hypoxia. Immunofluorescence staining and RT-PCR were used to evaluate the pathological changes in brain tissue cells and the expression of mRNA and proteins. 4OI was intraperitoneally injected into HI model mice to assess its anti-inflammatory and antioxidant effects. BV2 and C8D1A cells were cultured in vitro to study the effect of 4OI on the expression and nuclear translocation of Nrf2. We also used Nrf2-siRNA to further validate 4OI-induced Nrf2 pathway in astrocytes. RESULTS: We found that in the acute phase of HI, there was an accumulation of pyruvate and lactate in the hippocampal tissue, accompanied by oxidative stress and pro-inflammatory, as well as increased expression of antioxidative stress and anti-inflammatory genes. Treatment of 4OI could inhibit activation and proliferation of microglial cells and astrocytes, reduce neuronal death and relieve cognitive dysfunction in HI mice. Furthermore, 4OI enhanced nuclear factor erythroid-2-related factor (Nfe2l2; Nrf2) expression and nuclear translocation in astrocytes, reduced pro-inflammatory cytokine production, and increased antioxidant enzyme expression. CONCLUSION: Our study demonstrates that 4OI has a potential therapeutic effect on neuronal damage and cognitive deficits in HIE, potentially through the modulation of inflammation and oxidative stress pathways by Nrf2 in astrocytes.

Hepcidin deficiency impairs hippocampal neurogenesis and mediates brain atrophy and memory decline in mice.

BACKGROUND: Hepcidin is the master regulator of iron homeostasis. Hepcidin downregulation has been demonstrated in the brains of Alzheimer's disease (AD) patients. However, the mechanism underlying the role of hepcidin downregulation in cognitive impairment has not been elucidated. METHODS: In the present study, we generated GFAP-Cre-mediated hepcidin conditional knockout mice (HampGFAP cKO) to explore the effect of hepcidin deficiency on hippocampal structure and neurocognition. RESULTS: We found that the HampGFAP cKO mice developed AD-like brain atrophy and memory deficits. In particular, the weight of the hippocampus and the number of granule neurons in the dentate gyrus were significantly reduced. Further investigation demonstrated that the morphological change in the hippocampus of HampGFAP cKO mice was attributed to impaired neurogenesis caused by decreased proliferation of neural stem cells. Regarding the molecular mechanism, increased iron content after depletion of hepcidin followed by an elevated level of the inflammatory factor tumor necrosis factor-α accounted for the impairment of hippocampal neurogenesis in HampGFAP cKO mice. These observations were further verified in GFAP promoter-driven hepcidin knockdown mice and in Nestin-Cre-mediated hepcidin conditional knockout mice. CONCLUSIONS: The present findings demonstrated a critical role for hepcidin in hippocampal neurogenesis and validated the importance of iron and associated inflammatory cytokines as key modulators of neurodevelopment, providing insights into the potential pathogenesis of cognitive dysfunction and related treatments.

Itaconate alleviates anesthesia/surgery-induced cognitive impairment by activating a Nrf2-dependent anti-neuroinflammation and neurogenesis via gut-brain axis.

BACKGROUND: Postoperative cognitive dysfunction (POCD) is a common neurological complication of anesthesia and surgery in aging individuals. Neuroinflammation has been identified as a hallmark of POCD. However, safe and effective treatments of POCD are still lacking. Itaconate is an immunoregulatory metabolite derived from the tricarboxylic acid cycle that exerts anti-inflammatory effects by activating the nuclear factor erythroid 2-related factor 2 (Nrf2) pathway. In this study, we investigated the effects and underlying mechanism of 4-octyl itaconate (OI), a cell-permeable itaconate derivative, on POCD in aged mice. METHODS: A POCD animal model was established by performing aseptic laparotomy in 18-month-old male C57BL/6 mice under isoflurane anesthesia while maintaining spontaneous ventilation. OI was intraperitoneally injected into the mice after surgery. Primary microglia and neurons were isolated and treated to lipopolysaccharide (LPS), isoflurane, and OI. Cognitive function, neuroinflammatory responses, as well as levels of gut microbiota and their metabolites were evaluated. To determine the mechanisms underlying the therapeutic effects of OI in POCD, ML385, an antagonist of Nrf2, was administered intraperitoneally. Cognitive function, neuroinflammatory responses, endogenous neurogenesis, neuronal apoptosis, and Nrf2/extracellular signal-related kinases (ERK) signaling pathway were evaluated. RESULTS: Our findings revealed that OI treatment significantly alleviated anesthesia/surgery-induced cognitive impairment, concomitant with reduced levels of the neuroinflammatory cytokines IL-1ß and IL-6, as well as suppressed activation of microglia and astrocytes in the hippocampus. Similarly, OI treatment inhibited the expression of IL-1ß and IL-6 in LPS and isoflurane-induced primary microglia in vitro. Intraperitoneal administration of OI led to alterations in the gut microbiota and promoted the production of microbiota-derived metabolites associated with neurogenesis. We further confirmed that OI promoted endogenous neurogenesis and inhibited neuronal apoptosis in the hippocampal dentate gyrus of aged mice. Mechanistically, we observed a decrease in Nrf2 expression in hippocampal neurons both in vitro and in vivo, which was reversed by OI treatment. We found that Nrf2 was required for OI treatment to inhibit neuroinflammation in POCD. The enhanced POCD recovery and promotion of neurogenesis triggered by OI exposure were, at least partially, mediated by the activation of the Nrf2/ERK signaling pathway. CONCLUSIONS: Our findings demonstrate that OI can attenuate anesthesia/surgery-induced cognitive impairment by stabilizing the gut microbiota and activating Nrf2 signaling to restrict neuroinflammation and promote neurogenesis. Boosting endogenous itaconate or supplementation with exogenous itaconate derivatives may represent novel strategies for the treatment of POCD.

Therapeutic effects of orexin-A in sepsis-associated encephalopathy in mice.

BACKGROUND: Sepsis-associated encephalopathy (SAE) causes acute and long-term cognitive deficits. However, information on the prevention and treatment of cognitive dysfunction after sepsis is limited. The neuropeptide orexin-A (OXA) has been shown to play a protective role against neurological diseases by modulating the inflammatory response through the activation of OXR1 and OXR2 receptors. However, the role of OXA in mediating the neuroprotective effects of SAE has not yet been reported. METHODS: A mouse model of SAE was induced using cecal ligation perforation (CLP) and treated via intranasal administration of exogenous OXA after surgery. Mouse survival, in addition to cognitive and anxiety behaviors, were assessed. Changes in neurons, cerebral edema, blood-brain barrier (BBB) permeability, and brain ultrastructure were monitored. Levels of pro-inflammatory factors (IL-1ß, TNF-α) and microglial activation were also measured. The underlying molecular mechanisms were investigated by proteomics analysis and western blotting. RESULTS: Intranasal OXA treatment reduced mortality, ameliorated cognitive and emotional deficits, and attenuated cerebral edema, BBB disruption, and ultrastructural brain damage in mice. In addition, OXA significantly reduced the expression of the pro-inflammatory factors IL-1ß and TNF-α, and inhibited microglial activation. In addition, OXA downregulated the expression of the Rras and RAS proteins, and reduced the phosphorylation of P-38 and JNK, thus inhibiting activation of the MAPK pathway. JNJ-10,397,049 (an OXR2 blocker) reversed the effect of OXA, whereas SB-334,867 (an OXR1 blocker) did not. CONCLUSION: This study demonstrated that the intranasal administration of moderate amounts of OXA protects the BBB and inhibits the activation of the OXR2/RAS/MAPK pathway to attenuate the outcome of SAE, suggesting that OXA may be a promising therapeutic approach for the management of SAE.

Drop to Gate Nasal Drops Attenuates Sepsis-Induced Cognitive Dysfunction.

Nasal administration can bypass the blood-brain barrier and directly deliver drugs to the brain, providing a non-invasive route for central nervous system (CNS) diseases. Inspired by the appearance that a gate can block the outside world and the characteristics of the sol-gel transition can form a "gate" in the nasal cavity, a Drop to Gate nasal drop (DGND) is designed to set a gate in nose, which achieves protecting role from the influence of nasal environment. The DGND demonstrates the efficiency and application prospect of delivering drugs to the brain through the N-to-B. The effective concentration of single administration is increased through the hydrophobic interaction between C8-GelMA and SRT1720 (SA), and then cross-linked under UV to form nanogel, which can respond to MMP in the inflammatory microenvironment of sepsis-induced cognitive dysfunction. Finally, the SA/nanogel is compounded into the thermogel, which can respond to the nasal cavity temperature to form DGND in situ, increasing the residence time and delivery efficiency of drugs in the nasal cavity. In vitro, the DGND alleviates lipopolysaccharides (LPS)-induced BV2 inflammation. In vivo, DGND effectively targets the nasal mucosa and deliver drugs to the brain, which activate Sirt1 to alleviate inflammation mediated by microglia and improve cognitive dysfunction in sepsis mice.

Prevalence of Cognitive and Manual Dexterity Disorders Among Men Following Artificial Urinary Sphincter Placement.

PURPOSE: Cognitive ability and manual dexterity sufficient to operate an artificial urinary sphincter (AUS) are critical for device function and safety. We aimed to define the incidence of cognitive and/or dexterity disorders among men after AUS. We secondarily aimed to assess for association between these disorders and postimplant complications. MATERIALS AND METHODS: This is a retrospective cohort study using the SEER (Surveillance, Epidemiology, and End Results)-Medicare linked database (2000-2018). We included men ≥ 66 years diagnosed with prostate cancer between 2001 to 2015 who subsequently underwent AUS placement. We excluded patients with < 1-year continuous fee-for-service Medicare enrollment or cognitive and/or manual dexterity disorder diagnoses prior to AUS implant. Subsequent cognitive/dexterity disorders and implant-related complications were queried using appropriate ICD (International Classification of Diseases)-9/10 and/or CPT (Current Procedural Terminology) codes. Associations between cognitive/dexterity disorders and postimplant complications were assessed using extended Cox proportional hazards modeling. Secondary analysis focused on serious complications (device revision/removal, Fournier's gangrene, urethral erosion). RESULTS: We identified 1560 men who underwent AUS who met inclusion criteria. Median age was 73.0 (IQR 70-77) years. Cumulative incidence function analysis estimated 44% and 17% incidence of cognitive and manual dexterity disorder, respectively, at 15 years post-AUS. Presence of cognitive with/without manual dexterity disorder was associated with increased hazard of any, but not serious, complication during follow-up. CONCLUSIONS: A significant proportion of patients develop cognitive and/or manual dexterity disorders following AUS. These data support the need for close longitudinal monitoring after implant.

Apathy Symptoms, Physical and Cognitive Function, Health-Related Quality of Life, and Mortality in Older Patients With CKD: A Longitudinal Observational Study.

RATIONALE & OBJECTIVE: Apathy reflects diminished motivation, goal-directed behavior, and emotions, as well as less engagement in social interactions. Apathy overlaps with depression and is associated with cognitive decline. In the older individuals with chronic kidney disease (CKD), both depression and cognitive impairments are common, but apathy symptoms have been underreported. We investigated the occurrence of apathy symptoms and their associations with physical and cognitive functioning, health-related quality of life (HRQoL), and mortality in older patients with CKD. STUDY DESIGN: Prospective observational cohort study. SETTING & PARTICIPANTS: 180 outpatients aged≥65 years with estimated glomerular filtration rate≤20mL/min/1.73m2 from 5 Dutch nephrology centers. EXPOSURE: Apathy symptoms at baseline were considered present when a Geriatric Depression Scale's 3-item apathy subscale score was≥2 points. OUTCOME: Physical and cognitive functioning, HRQoL (assessed in annual geriatric assessments), and 4-year mortality. ANALYTICAL APPROACH: Linear regression for cross-sectional associations, linear regression models for longitudinal associations, and Cox regression models for mortality over 4 years of observation. RESULTS: Apathy symptoms were present in 64 patients (36%; 67% men; median age 75.5 years), of whom 32 (50%) had no depressive symptoms. At baseline, the presence of apathy symptoms was associated with significantly more frailty, more functional dependence, less physical capacity, lower visuoconstructive performance, worse delayed recall, and lower HRQoL scores. The presence of apathy symptoms at baseline was also associated with a higher mortality risk (hazard ratio, 2.3 [95% CI, 1.3-4.2], P=0.005 adjusted for age, sex, and high education level), but not with changes in physical and cognitive functioning or HRQoL during the follow-up period. LIMITATIONS: Risk of selection bias and residual confounding. CONCLUSIONS: Apathy symptoms were highly prevalent and associated with concurrent lower physical and cognitive status, lower HRQoL, and increased mortality. These findings highlight apathy as a potentially important clinical phenotype in older CKD patients. PLAIN-LANGUAGE SUMMARY: We observed that older kidney patients often present apathy symptoms, such as less motivation, fewer goal-directed behaviors, fewer emotions, and less social engagement. Prior research has not extensively described apathy in kidney disease. We investigated the link between apathy symptoms and poor outcomes. We measured physical functioning, cognitive functioning, and quality of life. We learned that one-third of our older kidney patients showed symptoms of apathy, only half of whom had symptoms of depression. Patients with apathy symptoms showed lower quality of life and lower physical and cognitive performance. They also had a higher risk of death. These findings highlight the need for awareness of apathy symptoms in older kidney patients.

Combining multimodal magnetic resonance brain imaging and machine learning to unravel neurocognitive function in non-neuropsychiatric systemic lupus erythematosus.

OBJECTIVE: To study whether multimodal brain MRI comprising permeability and perfusion measures coupled with machine learning can predict neurocognitive function in young patients with SLE without neuropsychiatric manifestations. METHODS: SLE patients and healthy controls (HCs) (≤40 years of age) underwent multimodal structural brain MRI that comprised voxel-based morphometry (VBM), magnetization transfer ratio (MTR) and dynamic contrast-enhanced (DCE) MRI in this cross-sectional study. Neurocognitive function assessed by Automated Neuropsychological Assessment Metrics was reported as the total throughput score (TTS). Olfactory function was assessed. A machine learning-based model (i.e. glmnet) was constructed to predict TTS. RESULTS: Thirty SLE patients and 10 HCs were studied. Both groups had comparable VBM, MTR, olfactory bulb volume (OBV), olfactory function and TTS. While after correction for multiple comparisons the uncorrected increase in the blood-brain barrier (BBB) permeability parameters compared with HCs did not remain evident in SLE patients, DCE-MRI perfusion parameters, notably an increase in right amygdala perfusion, was positively correlated with TTS in SLE patients (r = 0.636, false discovery rate P < 0.05). A machine learning-trained multimodal MRI model comprising alterations of VBM, MTR, OBV and DCE-MRI parameters mainly in the limbic system regions predicted TTS in SLE patients (r = 0.644, P < 0.0005). CONCLUSION: Multimodal brain MRI demonstrated increased right amygdala perfusion that was associated with better neurocognitive performance in young SLE patients without statistically significant BBB leakage and microstructural abnormalities. A machine learning-constructed multimodal model comprising microstructural, perfusion and permeability parameters accurately predicted neurocognitive performance in SLE patients.