The IRG1-itaconate axis protects from cholesterol-induced inflammation and atherosclerosis.

Atherosclerosis is fueled by a failure to resolve lipid-driven inflammation within the vasculature that drives plaque formation. Therapeutic approaches to reverse atherosclerotic inflammation are needed to address the rising global burden of cardiovascular disease (CVD). Recently, metabolites have gained attention for their immunomodulatory properties, including itaconate, which is generated from the tricarboxylic acid-intermediate cis-aconitate by the enzyme Immune Responsive Gene 1 (IRG1/ACOD1). Here, we tested the therapeutic potential of the IRG1-itaconate axis for human atherosclerosis. Using single-cell RNA sequencing (scRNA-seq), we found that IRG1 is up-regulated in human coronary atherosclerotic lesions compared to patient-matched healthy vasculature, and in mouse models of atherosclerosis, where it is primarily expressed by plaque monocytes, macrophages, and neutrophils. Global or hematopoietic Irg1-deficiency in mice increases atherosclerosis burden, plaque macrophage and lipid content, and expression of the proatherosclerotic cytokine interleukin (IL)-1ß. Mechanistically, absence of Irg1 increased macrophage lipid accumulation, and accelerated inflammation via increased neutrophil extracellular trap (NET) formation and NET-priming of the NLRP3-inflammasome in macrophages, resulting in increased IL-1ß release. Conversely, supplementation of the Irg1-itaconate axis using 4-octyl itaconate (4-OI) beneficially remodeled advanced plaques and reduced lesional IL-1ß levels in mice. To investigate the effects of 4-OI in humans, we leveraged an ex vivo systems-immunology approach for CVD drug discovery. Using CyTOF and scRNA-seq of peripheral blood mononuclear cells treated with plasma from CVD patients, we showed that 4-OI attenuates proinflammatory phospho-signaling and mediates anti-inflammatory rewiring of macrophage populations. Our data highlight the relevance of pursuing IRG1-itaconate axis supplementation as a therapeutic approach for atherosclerosis in humans.

Patients' experiences of medication management while navigating ongoing care between outpatient services: A qualitative case study of patients on hemodialysis.

Background: Patients on hemodialysis have complex medical diagnoses and medication regimens, requiring access to numerous health services and consultation with various healthcare providers. While interprofessional collaboration can optimize care among hemodialysis patients, these patients commonly experience medication-related problems and frequent hospitalizations resulting from miscommunications and mismanagement of medications. Objectives: This study aims to capture the lived experiences of patients on hemodialysis to reveal their medication management needs as they navigate ongoing care between various outpatient services. Methods: A qualitative methodology was used to explore the perspectives of hemodialysis patients. One-on-one, in-person, semi-structured interviews were conducted at an outpatient hemodialysis clinic located inside an urban teaching hospital. English-speaking adults 18 years and older who have been followed at the clinic for at least three months were selected through random, convenience sampling. Interviews were recorded and transcribed verbatim. Patients were recruited and data were collected iteratively and continued until data saturation was reached. Data was analyzed through the lens of the Picker Principles of Patient Centered Care using a general inductive approach. Results: A total of nine interviews were conducted. Two major themes, medication management and care navigation, were identified. Though patients had a wealth of knowledge about their medications, and they were motivated to self-manage their medications to enhance their well-being, they experienced barriers with medication management. Patients further expressed challenges with navigating care and spoke of the importance of having good rapport with healthcare providers who are attentive to their needs. Conclusions: The results revealed a need for improved support for self-care and interprofessional collaboration to possibly reduce the burden of medications and care fragmentation experienced by patients and improve continuity of care for patients.

Combined Arterial Hypertension and Ischemic Stroke Exaggerate Anesthesia-Related Hypotension and Cerebral Oxygenation Deficits: A Preclinical Study.

BACKGROUND: Intraoperative arterial hypotension (IOH) is a common side effect of general anesthesia (GA), associated with poor outcomes in ischemic stroke. While IOH is more prevalent with hypertension, it is unknown whether IOH may differ when GA is induced during ischemic stroke, versus other clinical settings. This is important given that many stroke patients receive GA for endovascular thrombectomy. METHODS: We evaluate the cardiovascular responses to volatile GA (isoflurane in 100% o2 ) before and during middle cerebral artery occlusion stroke in rats instrumented to record blood pressure (BP) and cerebral tissue oxygenation (p o2 ) in the projected penumbra, in clinically relevant cohorts of normotensive (Wistar rat, n = 10), treated hypertensive (spontaneously hypertensive [SH] + enalapril, n = 12), and untreated hypertensive (SH rat, n = 12). RESULTS: During baseline induction of GA, IOH was similar in normotensive, treated hypertensive, and untreated hypertensive rats during the induction phase (first 10 minutes) (-24 ± 15 vs -28 ± 22 vs -48 ± 24 mm Hg; P > .05) and across the procedure (-24 ± 13 vs -30 ± 35 vs -39 ± 27 mm Hg; P > .05). Despite the BP reduction, cerebral p o2 increased by ~50% in all groups during the procedure. When inducing GA after 2 hours, all stroke groups showed a greater magnitude IOH compared to baseline GA induction, with larger falls in treated (-79 ± 24 mm Hg; P = .0202) and untreated(-105 ± 43 mm Hg; P < .001) hypertensive rats versus normotensives (-49 ± 21 mm Hg). This was accompanied by smaller increases in cerebral p o2 in normotensive rats (19% ± 32%; P = .0144 versus no-stroke); but a decrease in cerebral p o2 in treated (-11% ± 19%; P = .0048) and untreated (-12% ± 15%; P = .0003) hypertensive rats. Sham animals (normotensive and hypertensive) showed similar magnitude and pattern of IOH when induced with GA before and after sham procedure. CONCLUSIONS: Our findings are the first demonstration that ischemic stroke per se increases the severity of IOH, particularly when combined with a prior history of hypertension; this combination appears to compromise penumbral perfusion.

How Well Do Rodent Models of Parkinson's Disease Recapitulate Early Non-Motor Phenotypes? A Systematic Review.

The prodromal phase of Parkinson's disease (PD) is characterised by many non-motor symptoms, and these have recently been posited to be predictive of later diagnosis. Genetic rodent models can develop non-motor phenotypes, providing tools to identify mechanisms underlying the early development of PD. However, it is not yet clear how reproducible non-motor phenotypes are amongst genetic PD rodent models, whether phenotypes are age-dependent, and the translatability of these phenotypes has yet to be explored. A systematic literature search was conducted on studies using genetic PD rodent models to investigate non-motor phenotypes; cognition, anxiety/depressive-like behaviour, gastrointestinal (GI) function, olfaction, circadian rhythm, cardiovascular and urinary function. In total, 51 genetic models of PD across 150 studies were identified. We found outcomes of most phenotypes were inconclusive due to inadequate studies, assessment at different ages, or variation in experimental and environmental factors. GI dysfunction was the most reproducible phenotype across all genetic rodent models. The mouse model harbouring mutant A53T, and the wild-type hα-syn overexpression (OE) model recapitulated the majority of phenotypes, albeit did not reliably produce concurrent motor deficits and nigral cell loss. Furthermore, animal models displayed different phenotypic profiles, reflecting the distinct genetic risk factors and heterogeneity of disease mechanisms. Currently, the inconsistent phenotypes within rodent models pose a challenge in the translatability and usefulness for further biomechanistic investigations. This review highlights opportunities to improve phenotype reproducibility with an emphasis on phenotypic assay choice and robust experimental design.

Long noncoding RNA CHROMR regulates antiviral immunity in humans.

Long noncoding RNAs (lncRNAs) have emerged as critical regulators of gene expression, yet their contribution to immune regulation in humans remains poorly understood. Here, we report that the primate-specific lncRNA CHROMR is induced by influenza A virus and SARS-CoV-2 infection and coordinates the expression of interferon-stimulated genes (ISGs) that execute antiviral responses. CHROMR depletion in human macrophages reduces histone acetylation at regulatory regions of ISG loci and attenuates ISG expression in response to microbial stimuli. Mechanistically, we show that CHROMR sequesters the interferon regulatory factor (IRF)-2-dependent transcriptional corepressor IRF2BP2, thereby licensing IRF-dependent signaling and transcription of the ISG network. Consequently, CHROMR expression is essential to restrict viral infection of macrophages. Our findings identify CHROMR as a key arbitrator of antiviral innate immune signaling in humans.

A Preclinical Model of Computerized Cognitive Training: Touchscreen Cognitive Testing Enhances Cognition and Hippocampal Cellular Plasticity in Wildtype and Alzheimer's Disease Mice.

With the growing popularity of touchscreen cognitive testing in rodents, it is imperative to understand the fundamental effects exposure to this paradigm can have on the animals involved. In this study, we set out to assess hippocampal-dependant learning in the APP/PS1 mouse model of Alzheimer's disease (AD) on two highly translatable touchscreen tasks - the Paired Associate Learning (PAL) task and the Trial Unique Non-Matching to Location (TUNL) task. Both of these tests are based on human tasks from the Cambridge Neuropsychological Test Automated Battery (CANTAB) and are sensitive to deficits in both mild cognitive impairment (MCI) and AD. Mice were assessed for deficits in PAL at 9-12 months of age, then on TUNL at 8-11 and 13-16 months. No cognitive deficits were evident in APP/PS1 mice at any age, contrary to previous reports using maze-based learning and memory tasks. We hypothesized that daily and long-term touchscreen training may have inadvertently acted as a cognitive enhancer. When touchscreen-tested mice were assessed on the Morris water maze, they showed improved task acquisition compared to naïve APP/PS1 mice and wild-type (WT) littermate controls. In addition, we show that touchscreen-trained WT and APP/PS1 mice show increased cell proliferation and immature neuron numbers in the dentate gyrus compared to behaviorally naïve WT and APP/PS1 mice. This result indicates that the touchscreen testing paradigm could improve cognitive performance, and/or mask an impairment, in experimental mouse models. This touchscreen-induced cognitive enhancement may involve increased neurogenesis, and possibly other forms of cellular plasticity. This is the first study to show increased numbers of proliferating cells and immature neurons in the hippocampus following touchscreen testing, and that touchscreen training can improve cognitive performance in maze-based spatial navigation tasks. This potential for touchscreen testing to induce cognitive enhancement, or other phenotypic shifts, in preclinical models should be considered in study design. Furthermore, touchscreen-mediated cognitive enhancement could have therapeutic implications for cognitive disorders.

Paraconduit Hiatal Hernia Following Esophagectomy: Incidence, Risk Factors, Outcomes and Repair.

BACKGROUND: Paraconduit hiatal hernia (PCHH) is a known complication of esophagectomy with significant morbidity. PCHH may be more common with the transition to a minimally invasive approach and improved survival. We studied the PCHH occurrence following minimally invasive esophagectomy to determine the incidence, treatment, and associated risk factors. METHODS: We retrospectively reviewed records of patients who underwent esophagectomy at an academic tertiary care center between 2013-2020. We divided the cohort into those who did and did not develop PCHH, identifying differences in demographics, perioperative characteristics and outcomes. We present video of our laparoscopic repair with mesh. RESULTS: Of 49 patients who underwent esophagectomy, seven (14%) developed PCHH at a median of 186 d (60-350 d) postoperatively. They were younger (57 versus 64 y, P< 0.01), and in cases of resection for cancer, more likely to develop tumor recurrence (71% versus 23%, P= 0.02). There was a significant difference in 2-y cancer free survival of patients with a PCHH (PCHH 19% versus no hernia 73%, P< 0.01), but no significant difference in 5-y overall survival (PCHH 36% versus no hernia 68%, P= 0.18). Five of seven PCHH were symptomatic and addressed surgically. Four PCHH repairs recurred at a median of 409 d. CONCLUSIONS: PCHH is associated with younger age and tumor recurrence, but not mortality. Safe repair of PCHH can be performed laparoscopically with or without mesh. Further studies, including systematic video review, are needed to address modifiable risk factors and identify optimal techniques for durable repair of post-esophagectomy PCHH.

QSMART: Quantitative susceptibility mapping artifact reduction technique.

PURPOSE: Quantitative susceptibility mapping (QSM) is a novel MR technique that allows mapping of tissue susceptibility values from MR phase images. QSM is an ill-conditioned inverse problem, and although several methods have been proposed in the field, in the presence of a wide range of susceptibility sources, streaking artifacts appear around high susceptibility regions and contaminate the whole QSM map. QSMART is a post-processing pipeline that uses two-stage parallel inversion to reduce the streaking artifacts and remove banding artifact at the cortical surface and around the vasculature. METHOD: Tissue and vein susceptibility values were separately estimated by generating a mask of vasculature driven from the magnitude data using a Frangi filter. Spatially dependent filtering was used for the background field removal step and the two susceptibility estimates were combined in the final QSM map. QSMART was compared to RESHARP/iLSQR and V-SHARP/iLSQR inversion in a numerical phantom, 7T in vivo single and multiple-orientation scans, 9.4T ex vivo mouse data, and 4.7T in vivo rat brain with induced focal ischemia. RESULTS: Spatially dependent filtering showed better suppression of phase artifacts near cortex compared to RESHARP and V-SHARP, while preserving voxels located within regions of interest without brain edge erosion. QSMART showed successful reduction of streaking artifacts as well as improved contrast between different brain tissues compared to the QSM maps obtained by RESHARP/iLSQR and V-SHARP/iLSQR. CONCLUSION: QSMART can reduce QSM artifacts to enable more robust estimation of susceptibility values in vivo and ex vivo.

Patients' and Caregivers' Attitudes Toward Deprescribing in Singapore.

BACKGROUND: Knowledge of decision-making preference of patients and caregivers is needed to facilitate deprescribing. This study aimed to assess the perspectives of caregivers and older adults towards deprescribing in an Asian population. Secondary objectives were to identify and compare characteristics associated with these attitudes and beliefs. METHOD: A cross-sectional survey of two groups of participants was conducted using the Revised Patients' Attitudes Towards Deprescribing questionnaire. Descriptive results were reported for participants' characteristics and questionnaire responses from four factors (belief in medication inappropriateness, medication burden, concerns about stopping, and involvement) and two global questions. Correlation between participant characteristics and their responses was analyzed. RESULTS: A total of 1,057 (615 older adults; 442 caregivers) participants were recruited from 10 institutions in Singapore. In which 511 (83.0%) older adults and 385 (87.1%) caregivers reported that they would be willing to stop one or more of their medications if their doctor said it was possible, especially among older adults recruited from acute-care hospitals (85.3%) compared with older adults in community pharmacies (73.6%). Individuals who take more than five medications and those with higher education were correlated with greater agreement in inappropriateness and involvement, respectively. CONCLUSIONS: Clinicians should consider discussing deprescribing with older adults and caregivers in their regular clinical practice, especially when polypharmacy is present. Further research is needed into how to engage older adults and caregivers in shared decision making based on their attitudes toward deprescribing.

AAV9 Edits Muscle Stem Cells in Normal and Dystrophic Adult Mice.

CRISPR editing of muscle stem cells (MuSCs) with adeno-associated virus serotype-9 (AAV9) holds promise for sustained gene repair therapy for muscular dystrophies. However, conflicting evidence exists on whether AAV9 transduces MuSCs. To rigorously address this question, we used a muscle graft model. The grafted muscle underwent complete necrosis before regenerating from its MuSCs. We injected AAV9.Cre into Ai14 mice. These mice express tdTomato upon Cre-mediated removal of a floxed stop codon. About 28%-47% and 24%-89% of Pax7+ MuSCs expressed tdTomato in pre-grafts and regenerated grafts (p > 0.05), respectively, suggesting AAV9 efficiently transduced MuSCs, and AAV9-edited MuSCs renewed successfully. Robust MuSC transduction was further confirmed by delivering AAV9.Cre to Pax7-ZsGreen-Ai14 mice in which Pax7+ MuSCs are genetically labeled by ZsGreen. Next, we co-injected AAV9.Cas9 and AAV9.gRNA to dystrophic mdx mice to repair the mutated dystrophin gene. CRISPR-treated and untreated muscles were grafted to immune-deficient, dystrophin-null NSG.mdx4cv mice. Grafts regenerated from CRISPR-treated muscle contained the edited genome and yielded 2.7-fold more dystrophin+ cells (p = 0.015). Importantly, increased dystrophin expression was not due to enhanced formation of revertant fibers or de novo transduction by residual CRISPR vectors in the graft. We conclude that AAV9 effectively transduces MuSCs. AAV9 CRISPR editing of MuSCs may provide enduring therapy.

Transgenic Mouse Models as Tools for Understanding How Increased Cognitive and Physical Stimulation Can Improve Cognition in Alzheimer's Disease.

Cognitive decline appears as a core feature of dementia, of which the most prevalent form, Alzheimer's disease (AD) affects more than 45 million people worldwide. There is no cure, and therapeutic options remain limited. A number of modifiable lifestyle factors have been identified that contribute to cognitive decline in dementia. Sedentary lifestyle has emerged as a major modifier and accordingly, boosting mental and physical activity may represent a method to prevent decline in dementia. Beneficial effects of increased physical activity on cognition have been reported in healthy adults, showing potential to harness exercise and cognitive stimulation as a therapy in dementia. 'Brain training' (cognitive stimulation) has also been investigated as an intervention protecting against cognitive decline with normal aging. Consequently, the utility of exercise regimes and/or cognitive stimulation to improve cognition in dementia in clinical populations has been a major area of study. However, these therapies are in their infancy and efficacy is unclear. Investigations utilising animal models, where dose and timing of treatment can be tightly controlled, have provided many mechanistic insights. Genetically engineered mouse models are powerful tools to investigate mechanisms underlying cognitive decline, and also how environmental manipulations can alter both cognitive outcomes and pathology. A myriad of effects following physical activity and housing in enriched environments have been reported in transgenic mice expressing Alzheimer's disease-associated mutations. In this review, we comprehensively evaluate all studies applying environmental enrichment and/or increased physical exercise to transgenic mouse models of Alzheimer's disease. It is unclear whether interventions must be applied before first onset of cognitive deficits to be effective. In order to determine the importance of timing of interventions, we specifically scrutinised studies exposing transgenic mice to exercise and environmental enrichment before and after first report of cognitive impairment. We discuss the strengths and weaknesses of these preclinical studies and suggest approaches for enhancing rigor and using mechanistic insights to inform future therapeutic interventions.

A guide to integrating immunohistochemistry and chemical imaging.

Chemical imaging provides new insight into the fundamental atomic, molecular, and biochemical composition of tissue and how they are interrelated in normal physiology. Visualising and quantifying products of pathogenic reactions long before structural changes become apparent also adds a new dimension to understanding disease pathogenesis. While chemical imaging in isolation is somewhat limited by the nature of information it can provide (e.g. peptides, metals, lipids, or functional groups), integrating immunohistochemistry allows simultaneous, targeted imaging of biomolecules while also mapping tissue composition. Together, this approach can provide invaluable information on the inner workings of the cell and the molecular basis of diseases.

Long-term outcome of upper extremity arteriovenous fistula using pSLOT: single-center longitudinal follow-up using a protocol-based approach.

INTRODUCTION: Functional arteriovenous fistula (AVF) is the best vascular access for end-stage renal disease patients. AVF maturation is variable and many require additional interventions to achieve functionality. Long-term benefits of such interventions are unclear. Using a protocol for AVF planning, creation, maturation evaluation and performing interventions based on objective findings along with maintaining a database on follow-up is necessary to evaluate this question.The aim of this study is to evaluate the long-term outcome of newly constructed AVFs using a protocol-based approach in a tertiary care academic center. METHODS: This is an observational study. Long-term outcomes of consecutive AVFs placed over a 5-year period using a protocol for creation, maturation evaluation and interventions based on objective findings were analyzed using a prospectively maintained clinical database. RESULTS: Functioning AVFs were achieved in 86.5% (n = 296) of 342 patients. Primary and secondary patency of 372 AVF procedures at 12, 24 and 60 months were 42.8%, 31.6% and 20.8%; and 81.8%, 77.6% and 71.7%, respectively. Functional patency at 12, 24 and 60 months were 95.1%, 88.7%, and 85.2%, respectively. Long-term function was similar for AVFs maturing with ≤4 interventions and without interventions. AVFs maturing with 2-4 interventions needed significantly more interventions to maintain long-term functional patency (p = 0.003). CONCLUSIONS: Piggyback straight-line on-lay technique (pSLOT) improves early outcome providing opportunity to identify other problems contributing to non-maturation. A large number of AVFs needing planned interventions to mature provide good long-term function. Establishing process of care guidelines for creation and follow-up has a potential to improve AVF outcome.

Successful use of minimal incision superficialization technique for arteriovenous fistula maturation.

BACKGROUND: Successful cannulation is an important prerequisite for a functional arteriovenous fistula (AVF). Reasons for unsuccessful cannulation of an AVF are multifactorial and poorly evaluated. In our experience, a needle access segment (NAS) with a length of 10 cm, <5 mm deep from the skin surface, and >6 mm diameter assessed objectively using duplex Doppler ultrasound (DDUS) imaging, in a fistula with brachial artery flow >500 mL/min, permits consistent cannulation. This report provides observational data on the NAS of the outflow veins after fistula creation and a detailed long-term outcome on AVFs that needed superficialization of the NAS using minimal incision superficialization technique (MIST) to make them suitable for cannulation. This report is based on prospectively collected data with a longitudinal follow-up in a large patient cohort. METHODS: A prospective database was used to analyze consecutive patients undergoing AVF until the study end point. All patients underwent a protocol-based maturation evaluation using color DDUS imaging. Unsuitable NAS were surgically corrected using superficialization (by MIST or lipectomy) of deeply situated veins or NAS reconstruction. RESULTS: Between February 1, 2007, and May 31, 2013, 617 new AVF surgeries were performed. Outflow vein superficialization (MIST or lipectomy) or NAS reconstruction was necessary in 226 of 585 procedures (38.6%) included in this analysis. Of these, 162 (72%) were performed using MIST, 50 (22%) with a single long incision, and 14 (6%) using lipectomy technique. Technical success for MIST was 100%, and only two fistulae failed to mature. The vein depth of 9.2 ± 3.2 mm during initial vessel mapping was similar to the pre-MIST depth of 9.1 ± 3.8 mm. Depth of NAS improved to 3.1 ± 1.0 mm after MIST. The secondary patency after MIST at 6, 12, 24, 48, and 60 months was 98%, 93.3%, 88.1%, 83.3%, and 80.9%. During the 400.8 post-MIST functional fistula-years, only 0.63 procedures per year were required to maintain AVF patency. CONCLUSIONS: Our data suggest that maturation of AVFs using objective criteria based on DDUS provides an opportunity to identify NAS problems in outflow veins before cannulation. Most of the of the AVF outflow veins (71.7%) could be transposed or superficialized using MIST, with excellent long-term outcomes.

Synchronization of Spontaneous Active Motility of Hair Cell Bundles.

Hair cells of the inner ear exhibit an active process, believed to be crucial for achieving the sensitivity of auditory and vestibular detection. One of the manifestations of the active process is the occurrence of spontaneous hair bundle oscillations in vitro. Hair bundles are coupled by overlying membranes in vivo; hence, explaining the potential role of innate bundle motility in the generation of otoacoustic emissions requires an understanding of the effects of coupling on the active bundle dynamics. We used microbeads to connect small groups of hair cell bundles, using in vitro preparations that maintain their innate oscillations. Our experiments demonstrate robust synchronization of spontaneous oscillations, with either 1:1 or multi-mode phase-locking. The frequency of synchronized oscillation was found to be near the mean of the innate frequencies of individual bundles. Coupling also led to an improved regularity of entrained oscillations, demonstrated by an increase in the quality factor.