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Epithelial barrier loss is a driver of intestinal and systemic diseases. Myosin light chain kinase (MLCK) is a key effector of barrier dysfunction and a potential therapeutic target, but enzymatic inhibition has unacceptable toxicity. Here, we show that a unique domain within the MLCK splice variant MLCK1 directs perijunctional actomyosin ring (PAMR) recruitment. Using the domain structure and multiple screens, we identify a domain-binding small molecule (divertin) that blocks MLCK1 recruitment without inhibiting enzymatic function. Divertin blocks acute, tumor necrosis factor (TNF)-induced MLCK1 recruitment as well as downstream myosin light chain (MLC) phosphorylation, barrier loss, and diarrhea in vitro and in vivo. Divertin corrects barrier dysfunction and prevents disease development and progression in experimental inflammatory bowel disease. Beyond applications of divertin in gastrointestinal disease, this general approach to enzymatic inhibition by preventing access to specific subcellular sites provides a new paradigm for safely and precisely targeting individual properties of enzymes with multiple functions.

BackgroundPrompted by the revolution in high-throughput sequencing and its potential impact for treating cancer patients, we initiated a clinical research study to compare the ability of different sequencing assays and analysis methods to analyze glioblastoma tumors and generate real-time potential treatment options for physicians.MethodsA consortium of seven institutions in New York City enrolled 30 patients with glioblastoma and performed tumor whole genome sequencing (WGS) and RNA sequencing (RNA-seq; collectively WGS/RNA-seq); 20 of these patients were also analyzed with independent targeted panel sequencing. We also compared results of expert manual annotations with those from an automated annotation system, Watson Genomic Analysis (WGA), to assess the reliability and time required to identify potentially relevant pharmacologic interventions.ResultsWGS/RNAseq identified more potentially actionable clinical results than targeted panels in 90% of cases, with an average of 16-fold more unique potentially actionable variants identified per individual; 84 clinically actionable calls were made using WGS/RNA-seq that were not identified by panels. Expert annotation and WGA had good agreement on identifying variants [mean sensitivity=0.71, SD=0.18 and positive predictive value (PPV)=0.80, SD=0.20] and drug targets when the same variants were called (mean sensitivity=0.74, SD=0.34 and PPV=0.79, SD=0.23) across patients. Clinicians used the information to modify their treatment plan 10% of the time.ConclusionThese results present the first comprehensive comparison of technical and machine augmented analysis of targeted panel and WGS/RNA-seq to identify potential cancer treatments.

Tissue-resident macrophages are the most abundant immune cell population in healthy adipose tissue. Adipose tissue macrophages (ATMs) change during metabolic stress and are thought to contribute to metabolic syndrome. Here, we studied ATM subpopulations in steady state and in response to nutritional and infectious challenges. We found that tissue-resident macrophages from healthy epididymal white adipose tissue (eWAT) tightly associate with blood vessels, displaying very high endocytic capacity. We refer to these cells as vasculature-associated ATMs (VAMs). Chronic high-fat diet (HFD) results in the accumulation of a monocyte-derived CD11c(+)CD64(+ )double-positive (DP) macrophage eWAT population with a predominant anti-inflammatory/detoxifying gene profile, but reduced endocytic function. In contrast, fasting rapidly and reversibly leads to VAM depletion, while acute inflammatory stress induced by pathogens transiently depletes VAMs and simultaneously boosts DP macrophage accumulation. Our results indicate that ATM populations dynamically adapt to metabolic stress and inflammation, suggesting an important role for these cells in maintaining tissue homeostasis.

BackgroundIntimate partner violence (IPV) during pregnancy is associated with adverse maternal and child health outcomes, including poor mental health. Previous IPV research has largely focused on women's victimization experiences; however, evidence suggests young women may be more likely to engage in bilateral violence (report both victimization and perpetration) or perpetrate IPV (unilateral perpetration) during pregnancy than to report being victimized (unilateral victimization). This study examined prevalence of unilateral victimization, unilateral perpetration, and bilateral violence, and the association between these IPV profiles and mental health outcomes during pregnancy among young, low-income adolescents.MethodsSurvey data were collected from 930 adolescents (14-21years; 95.4% Black and Latina) from fourteen Community Health Centers and hospitals in New York City during second and third trimester of pregnancy. Multivariable regression models tested the association between IPV profiles and prenatal depression, anxiety, and distress, adjusting for known predictors of psychological morbidity.ResultsThirty-eight percent of adolescents experienced IPV during their third trimester of pregnancy. Of these, 13% were solely victims, 35% were solely perpetrators, and 52% were engaged in bilateral violence. All women with violent IPV profiles had significantly higher odds of having depression and anxiety compared to individuals reporting no IPV. Adolescents experiencing bilateral violence had nearly 4-fold higher odds of depression (OR=3.52, 95% CI: 2.43, 5.09) and a nearly 5-fold increased likelihood of anxiety (OR=4.98, 95% CI: 3.29, 7.55). Unilateral victims and unilateral perpetrators were also at risk for adverse mental health outcomes, with risk of depression and anxiety two- to three-fold higher, compared to pregnant adolescents who report no IPV. Prenatal distress was higher among adolescents who experienced bilateral violence (OR=2.84, 95% CI: 1.94, 4.16) and those who were unilateral victims (OR=2.21, 95% CI: 1.19, 4.12).ConclusionsAll violent IPV profiles were associated with adverse mental health outcomes among pregnant adolescents, with bilateral violence having the most detrimental associations. Comprehensive IPV screening for both victimization and perpetration experiences during pregnancy is warranted. Clinical and community prevention efforts should target pregnant adolescents and their partners to reduce their vulnerability to violence and its adverse consequences.

How cells correct deviations from a mean cell size at mitosis remains uncertain. Classical cell-size homeostasis models are the sizer, timer, and adder [1]. Sizers postulate that cells divide at some threshold size; timers, that cells grow for a set time; and adders, that cells add a constant volume before division. Here, we show that a size-based probabilistic model of cell-size control at the G2/M transition (P(Div)) can generate realistic cell-size homeostasis in silico. In fission yeast cells, Cyclin B-Cdc13 scales with size, and we propose that this increases the like-lihood of mitotic entry, while molecular noise in its expression adds a probabilistic component to the model. Varying Cdc13 expression levels exogenously using a newly developed tetracycline inducible promoter shows that both the level and variability of its expression influence cell size at division. Our results demonstrate that as cells grow larger, their probability of dividing increases, and this is sufficient to generate cell-size homeostasis. Size-correlated Cdc13 expression forms part of the molecular circuitry of this system.

Analytical antiretroviral treatment interruption (ATI) is an important feature of HIV research, seeking to achieve sustained viral suppression in the absence of antiretroviral therapy (ART) when the goal is to measure effects of novel therapeutic interventions on time to viral load rebound or altered viral setpoint. Trials with ATIs also intend to determine host, virological, and immunological markers that are predictive of sustained viral control off ART. Although ATI is increasingly incorporated into proof-of-concept trials, no consensus has been reached on strategies to maximise its utility and minimise its risks. In addition, differences in ATI trial designs hinder the ability to compare efficacy and safety of interventions across trials. Therefore, we held a meeting of stakeholders from many interest groups, including scientists, clinicians, ethicists, social scientists, regulators, people living with HIV, and advocacy groups, to discuss the main challenges concerning ATI studies and to formulate recommendations with an emphasis on strategies for risk mitigation and monitoring, ART resumption criteria, and ethical considerations. In this Review, we present the major points of discussion and consensus views achieved with the goal of informing the conduct of ATIs to maximise the knowledge gained and minimise the risk to participants in clinical HIV research.

The size of the membrane-bound nucleus scales with cell size in a wide range of cell types but the mechanisms determining overall nuclear size remain largely unknown. Here we investigate the role of fission yeast inner nuclear membrane proteins in determining nuclear size, and propose that the Lap2-Emerin-Manl domain protein Lem2 acts as a barrier to membrane flow between the nucleus and other parts of the cellular membrane system. Lem2 deletion increases membrane flow into and out of the nuclear envelope in response to changes in membrane synthesis and nucleocytoplasmic transport, altering nuclear size. The endoplasmic reticulum protein Lnp1 acts as a secondary barrier to membrane flow, functionally compensating for lack of Lem2. We propose that this is part of the mechanism that maintains nuclear size proportional to cellular membrane content and thus to cell size. Similar regulatory principles may apply to other organelles in the eukaryotic subcellular membrane network.

Bacteriophage-derived lysins are cell-wall-hydrolytic enzymes that represent a potential new class of antibacterial therapeutics in development to address burgeoning antimicrobial resistance. CF-301, the lead compound in this class, is in clinical development as an adjunctive treatment to potentially improve clinical cure rates of Staphylococcus aureus bacteremia and infective endocarditis (IE) when used in addition to antibiotics. In order to profile the activity of CF-301 in a clinically relevant milieu, we assessed its in vitro activity in human blood versus in a conventional testing medium (cation-adjusted Mueller-Hinton broth [caMHB]). CF-301 exhibited substantially greater potency (32 to >= 100-fold) in human blood versus caMHB in three standard microbiologic testing formats (e.g., broth dilution MICs, checkerboard synergy, and time-kill assays). We demonstrated that CF-301 acted synergistically with two key human blood factors, human serum lysozyme (HuLYZ) and human serum albumin (HSA), which normally have no nascent antistaphylococcal activity, against a prototypic methicillin-resistant S. aureus (MRSA) strain (MW2). Similar in vitro enhancement of CF-301 activity was also observed in rabbit, horse, and dog (but not rat or mouse) blood. Two well-established MRSA IE models in rabbit and rat were used to validate these findings in vivo by demonstrating comparable synergistic efficacy with standard-of-care anti-MRSA antibiotics at >= 100-fold lower lysin doses in the rabbit than in the rat model. The unique properties of CF-301 that enable bactericidal potentiation of antimicrobial activity via activation of "latent" host factors in human blood may have important therapeutic implications for durable improvements in clinical outcomes of serious antibiotic-resistant staphylococcal infections.

The HIV-1 envelope glycoprotein (Env) (gp120-gp41)(3) is the target for neutralizing antibodies and antibody-dependent cellular cytotoxicity (ADCC). HIV-1 Env is flexible, sampling different conformational states. Before engaging CD4, Env adopts a closed conformation (State 1) that is largely antibody resistant. CD4 binding induces an intermediate state (State 2), followed by an open conformation (State 3) that is susceptible to engagement by antibodies that recognize otherwise occluded epitopes. We investigate conformational changes in Env that induce ADCC in the presence of a smallmolecule CD4-mimetic compound (CD4mc). We uncover an asymmetric Env conformation (State 2A) recognized by antibodies targeting the conserved gp120 inner domain and mediating ADCC. Sera from HIV+ individuals contain these antibodies, which can stabilize Env State 2A in combination with CD4mc. Additionally, triggering State 2A on HIV-infected primary CD4(+) T cells exposes epitopes that induce ADCC. Strategies that induce this Env conformation may represent approaches to fight HIV-1 infection.

Introduction: Atopic dermatitis (AD) is the most common inflammatory skin disease, yet until recently there were no safe systemic therapies approved for the long-term management of AD in adult patients. A deeper understanding of disease pathogenesis and identification of molecular and cellular changes has resulted in a rapidly evolving pipeline of therapeutics that holds promise for safer long-term control. Areas covered: In this review, we highlight the growing arsenal of biologic and small molecule antagonists that target pathways implicated in AD pathogenesis. Evidence that AD is driven by multiple immune axes extending beyond the Th2 polarization has resulted in therapies targeting additional pathways, including the Th22, Th17/IL-23, and JAK-STAT pathways. Pruritus, a hallmark of AD, has been linked to multiple mechanisms and various therapeutics have emerged in response to alternative hypotheses. Expert opinion: Despite the assumption that AD has a common disease mechanism, recent studies indicate that the disorder is characterized by several phenotypes and therapy may need to be tailored to the unique immune traits of specific phenotypes. Targeted therapy should complement and expand our molecular map of AD across the various phenotypic iterations and help push AD pharmacotherapy into a new era of personalized medicine.