LRRK2 kinase activity restricts NRF2-dependent mitochondrial protection in microglia.

Mounting evidence supports a critical role for central nervous system (CNS) glial cells in neuroinflammation and neurodegenerative diseases, including Alzheimer's disease (AD), Parkinson's Disease (PD), Multiple Sclerosis (MS), as well as neurovascular ischemic stroke. Previously, we found that loss of the PD-associated gene leucine-rich repeat kinase 2 (Lrrk2) in macrophages, peripheral innate immune cells, induced mitochondrial stress and elevated basal expression of type I interferon (IFN) stimulated genes (ISGs) due to chronic mitochondrial DNA engagement with the cGAS/STING DNA sensing pathway. Here, we report that loss of LRRK2 results in a paradoxical response in microglial cells, a CNS-specific macrophage population. In primary murine microglia and microglial cell lines, loss of Lrrk2 reduces tonic IFN signaling leading to a reduction in ISG expression. Consistent with reduced type I IFN, mitochondria from Lrrk2 KO microglia are protected from stress and have elevated metabolism. These protective phenotypes involve upregulation of NRF2, an important transcription factor in the response to oxidative stress and are restricted by LRRK2 kinase activity. Collectively, these findings illustrate a dichotomous role for LRRK2 within different immune cell populations and give insight into the fundamental differences between immune regulation in the CNS and the periphery.

Contrast Media in Pregnant and Lactating Patients, From the AJR Special Series on Contrast Media.

IV contrast media improve the diagnostic power of radiology examinations. These media include gadolinium-based contrast media and iron-oxide nanoparticles for MRI, iodinated contrast material for CT, microbubbles for ultrasound, and radiopharmaceuticals for nuclear medicine. As for all medications, contrast media carry risks, which may be heightened in the conditions of pregnancy and lactation. Radiologists must understand the potential risks from contrast media exposure to the pregnant patient, fetus, and nursing infant, as well as understand these administrations' impact on examinations' clinical utility. This article reviews the available literature on these media, along with key regulatory bodies' and professional societies' current recommendations for their use, in the settings of pregnancy and lactation. This knowledge should help radiologists make well-reasoned risk-benefit analyses regarding contrast media administration and provide informed consent discussions with pregnant and nursing patients in whom contrast media administration is being considered. This information and analysis can also assist facilities in designing policies and standard operating procedures of possible clinical benefit to the pregnant patient, fetus, or nursing infant, balancing contrast media exposure considerations versus augmented diagnostic capabilities.

"I Didn't Realize How Hard It Was Going to Be Just Transitioning Back into Life": A Qualitative Exploration of Outcomes for Survivors of Pediatric Septic Shock.

Recovery following pediatric critical illness is multifaceted and complex. While most critically ill children survive, many experience morbidities in physical, emotional, cognitive, and social function. We aimed to deeply explore and describe the multidimensional impact of pediatric septic shock for affected children and their families at the granular level using exploratory qualitative methodology. We performed semistructured telephone interviews of adolescents and caregivers of children admitted with community-acquired septic shock to two tertiary pediatric intensive care units in the United States. Interviews were conducted within two years of hospital admission, and were recorded, transcribed, and analyzed using thematic analysis. Two adolescents and 10 caregivers were interviewed. Participants described meaningful and long-lasting outcomes of septic shock on multiple dimensions of their lives. The adolescents and caregivers described substantial negative consequences on physical health and function which resulted in increased medical complexity and heightened caregiver vigilance. The physical impact led to substantial psychosocial consequences for both the child and family, including social isolation. Most caregivers expressed that septic shock was transformational in their lives, with some caregivers describing posttraumatic growth. This preliminary study provides a novel, granular view of the multidimensional impact of septic shock in pediatric patients and their families. Exploring these experiences through qualitative methodology provides greater insight into important patient and family outcomes. Deeper understanding of these outcomes may support the development of meaningful interventions to improve quality of life for children and their families following critical illness.

Severe acute myositis and myocarditis on initiation of 6-weekly pembrolizumab post-COVID-19 mRNA vaccination.

We describe three cases of critical acute myositis with myocarditis occurring within 22 days of each other at a single institution, all within 1 month of receiving the initial cycle of the anti-PD-1 drug pembrolizumab. Analysis of T cell receptor repertoires from peripheral blood and tissues revealed a high degree of clonal expansion and public clones between cases, with several T cell clones expanded within the skeletal muscle putatively recognizing viral epitopes. All patients had recently received a COVID-19 mRNA booster vaccine prior to treatment and were positive for SARS-CoV2 Spike antibody. In conclusion, we report a series of unusually severe myositis and myocarditis following PD-1 blockade and the COVID-19 mRNA vaccination.

Brucella-driven host N-glycome remodeling controls infection.

Many powerful methods have been employed to elucidate the global transcriptomic, proteomic, or metabolic responses to pathogen-infected host cells. However, the host glycome responses to bacterial infection remain largely unexplored, and hence, our understanding of the molecular mechanisms by which bacterial pathogens manipulate the host glycome to favor infection remains incomplete. Here, we address this gap by performing a systematic analysis of the host glycome during infection by the bacterial pathogen Brucella spp. that cause brucellosis. We discover, surprisingly, that a Brucella effector protein (EP) Rhg1 induces global reprogramming of the host cell N-glycome by interacting with components of the oligosaccharide transferase complex that controls N-linked protein glycosylation, and Rhg1 regulates Brucella replication and tissue colonization in a mouse model of brucellosis, demonstrating that Brucella exploits the EP Rhg1 to reprogram the host N-glycome and promote bacterial intracellular parasitism, thereby providing a paradigm for bacterial control of host cell infection.

Serine/arginine-rich splicing factor 7 promotes the type I interferon response by activating Irf7 transcription.

Tight regulation of macrophage immune gene expression is required to fight infection without risking harmful inflammation. The contribution of RNA-binding proteins (RBPs) to shaping the macrophage response to pathogens remains poorly understood. Transcriptomic analysis reveals that a member of the serine/arginine-rich (SR) family of mRNA processing factors, SRSF7, is required for optimal expression of a cohort of interferon-stimulated genes in macrophages. Using genetic and biochemical assays, we discover that in addition to its canonical role in regulating alternative splicing, SRSF7 drives transcription of interferon regulatory transcription factor 7 (IRF7) to promote antiviral immunity. At the Irf7 promoter, SRSF7 maximizes STAT1 transcription factor binding and RNA polymerase II elongation via cooperation with the H4K20me1 histone methyltransferase KMT5a (SET8). These studies define a role for an SR protein in activating transcription and reveal an RBP-chromatin network that orchestrates macrophage antiviral gene expression.

The early macrophage response to pathogens requires dynamic regulation of the nuclear paraspeckle.

To ensure a robust immune response to pathogens without risking immunopathology, the kinetics and amplitude of inflammatory gene expression in macrophages need to be exquisitely well controlled. There is a growing appreciation for stress-responsive membraneless organelles (MLOs) regulating various steps of eukaryotic gene expression in response to extrinsic cues. Here, we implicate the nuclear paraspeckle, a highly ordered biomolecular condensate that nucleates on the Neat1 lncRNA, in tuning innate immune gene expression in murine macrophages. In response to a variety of innate agonists, macrophage paraspeckles rapidly aggregate (0.5 h poststimulation) and disaggregate (2 h poststimulation). Paraspeckle maintenance and aggregation require active transcription and MAPK signaling, whereas paraspeckle disaggregation requires degradation of Neat1 via the nuclear RNA exosome. In response to lipopolysaccharide treatment, Neat1 KO macrophages fail to properly express a large cohort of proinflammatory cytokines, chemokines, and antimicrobial mediators. Consequently, Neat1 KO macrophages cannot control replication of Salmonella enterica serovar Typhimurium or vesicular stomatitis virus. These findings highlight a prominent role for MLOs in orchestrating the macrophage response to pathogens and support a model whereby dynamic assembly and disassembly of paraspeckles reorganizes the nuclear landscape to enable inflammatory gene expression following innate stimuli.

Ten year real world experience with ultrafiltration for the management of acute decompensated heart failure.

Background: Randomized controlled trials (RCT) of ultrafiltration (UF) have demonstrated conflicting results regarding its efficacy and safety. Objective: We reviewed 10 years of data for adjustable UF during heart failure hospitalizations in a real world cohort. Methods: We performed a retrospective, single center analysis of 335 consecutive patients treated with adjustable rate UF using the CHF Solutions Aquadex Flex Flo System from 2009 to 2019. Results: Compared to previous RCTs investigating UF, our cohort was older, with worse renal impairment and more antecedent HF hospitalizations in the year preceding therapy. Mean fluid removal with UF was 14.6 l. Mean weight loss with UF was 15.6 lbs (range 0.2-57 lbs) and was sustained at 1-2 week follow-up. Mean creatinine change upon stopping UF, at discharge and follow-up (mean 30 days) was +0.11 mg/dl, +0.07 mg/dl and +0.11 mg/dl, respectively. HF rehospitalizations at 30 days, 90 days and 1 year were 12.4 %, 14.9 % and 27.3 % respectively. On average patients had 1.74 fewer hospitalizations for HF in the year following UF when compared to 12 months preceding UF. Major bleeding defined as requiring discontinuation of anticoagulation occurred in 3.6 % of patients. Conclusions: Compared with previous UF trials, our study demonstrates that UF compares favorably for HF rehospitalizations, renal function response, and weight/volume loss. Importantly, our real world experience allowed for the adjustment of UF rate during therapy and we believe this is a major contributor to our favorable outcomes. In clinical practice, UF can be a safe and effective strategy for decongestion.