Citations

Sonic hedgehog signaling regulates processes of embryonic development across multiple tissues, yet factors regulating context-specific Shh signaling remain poorly understood. Exome sequencing of families with polymicrogyria (disordered cortical folding) revealed multiple individuals with biallelic deleterious variants in TMEM161B , which encodes a multi-pass transmembrane protein of unknown function. Tmem161b null mice demonstrated holoprosencephaly, craniofacial midline defects, eye defects, and spinal cord patterning changes consistent with impaired Shh signaling, but were without limb defects, suggesting a CNS-specific role of Tmem161b. Tmem161b depletion impaired the response to Smoothened activation in vitro and disrupted cortical histogenesis in vivo in both mouse and ferret models, including leading to abnormal gyration in the ferret model. Tmem161b localizes non-exclusively to the primary cilium, and scanning electron microscopy revealed shortened, dysmorphic, and ballooned ventricular zone cilia in the Tmem161b null mouse, suggesting that the Shh-related phenotypes may reflect ciliary dysfunction. Our data identify TMEM161B as a regulator of cerebral cortical gyration, as involved in primary ciliary structure, as a regulator of Shh signaling, and further implicate Shh signaling in human gyral development.

NAFLD will soon be the most common indication for liver transplantation (LT). In NAFLD, HCC may occur at earlier stages of fibrosis and present with more advanced tumor stage, raising concern for aggressive disease. Thus, adult LT recipients with HCC from 20 US centers transplanted between 2002 and 2013 were analyzed to determine whether NAFLD impacts recurrence-free post-LT survival. Five hundred and thirty-eight (10.8%) of 4981 total patients had NAFLD. Patients with NAFLD were significantly older (63 vs. 58, p<0.001), had higher body mass index (30.5 vs. 27.4, p<0.001), and were more likely to have diabetes (57.3% vs. 28.8%, p<0.001). Patients with NAFLD were less likely to receive pre-LT locoregional therapy (63.6% vs. 72.9%, p<0.001), had higher median lab MELD (15 vs. 13, p<0.001) and neutrophil-lymphocyte ratio (3.8 vs. 2.9, p<0.001), and were more likely to have their maximum pre-LT alpha fetoprotein at time of LT (44.1% vs. 36.1%, p<0.001). NAFLD patients were more likely to have an incidental HCC on explant (19.4% vs. 10.4%, p<0.001); however, explant characteristics including tumor differentiation and vascular invasion were not different between groups. Comparing NAFLD and non-NAFLD patients, the 1, 3, and 5-year cumulative incidence of recurrence (3.1%, 9.1%, 11.5% vs. 4.9%, 10.1%, 12.6%, p=0.36) and recurrence-free survival rates (87%, 76%, and 67% vs. 87%, 75%, and 67%, p=0.97) were not different. In competing risks analysis, NAFLD did not significantly impact recurrence in univariable (HR: 0.88, p=0.36) nor in adjusted analysis (HR: 0.91, p=0.49). With NAFLD among the most common causes of HCC and poised to become the leading indication for LT, a better understanding of disease-specific models to predict recurrence is needed. In this NAFLD cohort, incidental HCCs were common, raising concerns about early detection. However, despite less locoregional therapy and high neutrophil-lymphocyte ratio, explant tumor characteristics and post-transplant recurrence-free survival were not different compared to non-NAFLD patients.

Genome-wide fragmentation patterns in cell-free DNA (cfDNA) in plasma are strongly influenced by cellular origin due to variation in chromatin accessibility across cell types. Such differences between healthy and cancer cells provide the opportunity for development of novel cancer diagnostics. Here, we investigated whether analysis of cfDNA fragment end positions and their surrounding DNA sequences reveals the presence of tumor-derived DNA in blood. We performed genome-wide analysis of cfDNA from 521 samples and analyzed sequencing data from an additional 2147 samples, including healthy individuals and patients with 11 different cancer types. We developed a metric based on genome-wide differences in fragment positioning, weighted by fragment length and GC content [information-weighted fraction of aberrant fragments (iwFAF)]. We observed that iwFAF strongly correlated with tumor fraction, was higher for DNA fragments carrying somatic mutations, and was higher within genomic regions affected by copy number amplifications. We also calculated sample-level means of nucleotide frequencies observed at genomic positions spanning fragment ends. Using a combination of iwFAF and nine nucleotide frequencies from three positions surrounding fragment ends, we developed a machine learning model to differentiate healthy individuals from patients with cancer. We observed an area under the receiver operative characteristic curve (AUC) of 0.91 for detection of cancer at any stage and an AUC of 0.87 for detection of stage I cancer. Our findings remained robust with as few as 1 million fragments analyzed per sample, demonstrating that analysis of fragment ends can become a cost-effective and accessible approach for cancer detection and monitoring.

Abstract Neurofilament light chain, a putative measure of neuronal damage, is measurable in blood and CSF and is predictive of cognitive function in individuals with Alzheimer’s disease. There has been limited prior work linking neurofilament light and functional connectivity, and no prior work has investigated neurofilament light associations with functional connectivity in autosomal dominant Alzheimer’s disease. Here, we assessed relationships between blood neurofilament light, cognition, and functional connectivity in a cross-sectional sample of 106 autosomal dominant Alzheimer’s disease mutation carriers and 76 non-carriers. We employed an innovative network-level enrichment analysis approach to assess connectome-wide associations with neurofilament light. Neurofilament light was positively correlated with deterioration of functional connectivity within the default mode network and negatively correlated with connectivity between default mode network and executive control networks, including the cingulo-opercular, salience, and dorsal attention networks. Further, reduced connectivity within the default mode network and between the default mode network and executive control networks was associated with reduced cognitive function. Hierarchical regression analysis revealed that neurofilament levels and functional connectivity within the default mode network and between the default mode network and the dorsal attention network explained significant variance in cognitive composite scores when controlling for age, sex, and education. A mediation analysis demonstrated that functional connectivity within the default mode network and between the default mode network and dorsal attention network partially mediated the relationship between blood neurofilament light levels and cognitive function. Our novel results indicate that blood estimates of neurofilament levels correspond to direct measurements of brain dysfunction, shedding new light on the underlying biological processes of Alzheimer’s disease. Further, we demonstrate how variation within key brain systems can partially mediate the negative effects of heightened total serum neurofilament levels, suggesting potential regions for targeted interventions. Finally, our results lend further evidence that low-cost and minimally invasive blood measurements of neurofilament may be a useful marker of brain functional connectivity and cognitive decline in Alzheimer’s disease.

Abstract Previously, we reported that killing tumor cells in vivo with the HSV thymidine kinase/ganciclovir system generates potent antitumor immunity, determined in part by the mechanism by which the cells die and by the levels of inducible heat shock protein (hsp) expression induced during the process of cell death. Here, we show that induction of hsp70 expression induces an infiltrate of T cells, macrophages, and predominantly dendritic cells (DCs) into the tumors as well as an intratumoral profile of Th1 cytokine expression (IFN-γ, TNF-α, and IL-12) and enhances immunogenicity via a T cell-mediated mechanism. In addition, the protection conferred by hsp70 is both tumor and cell specific. We also demonstrate that hsp70 targets immature APC to make them significantly more able to capture Ags. This is likely to optimize cross-priming of the infiltrating APC with tumor Ags, which are simultaneously being released by the dying cells. In addition, using an Myc epitope-tagged hsp70 expression vector, we present evidence that hsp70 released from dying tumor cells is taken up directly into DCs and may, therefore, be involved in direct chaperoning of Ags into DCs. Taken together, our data suggest that hsp70 induction serves to signal the immune system of the presence of an immunologically relevant (dangerous) situation against which an immune reaction should be raised.

Abstract The plasma membrane serves as an important site for the interaction of macrophages and lymphocytes in antigen recognition and of macrophages and foreign agents in inflammatory responses. Despite the critical role of the macrophage membrane in these reactions, studies on the biochemical and functional characteristics of macrophage membranes which need to be performed have been limited by the lack of suitable methods for the isolation of macrophage plasma membranes that maintain functional and antigenic membrane markers. Recently a new method for membrane isolation has been reported which is based on the observation that a variety of sulfhydryl blocking agents can induce the shedding of plasma membrane vesicles of monolayer cell lines. In this paper we demonstrate that guinea pig peritoneal exudate macrophages can also be induced to shed significant quantities of plasma membrane vesicles by such reagents, in particular with a low m.w. aldehyde, and that these vesicles can be isolated by centrifugation. Vesiculation in macrophages is potentiated by disulfide reducing agents, such as dithiothreitol, and by calcium ions. Maximum vesiculation is observed when well spread macrophage monolayers are incubated in a slightly hypertonic vesiculant at pH 7.0 for 2 hr at 37°C. Brief exposure of macrophages to a vesiculant for intervals as short as 30 min is also effective. Macrophage vesicles shed from the cell surface by this procedure have been found to contain receptors for concanavalin A, wheat germ agglutinin, phytohemagglutinin, and lentil lectin. Vesicles also contain Fc and complement (C3) receptors and form rosettes with thymic lymphocytes. It is suggested that macrophage plasma membrane vesicles isolated by this technique should serve as a valuable new system to study the biochemical characteristics of macrophage plasma membranes and their role in immunologic reactions.

Various pharmacotherapies exist for heart failure with preserved ejection fraction (HFpEF), but with unclear comparative efficacy. We searched EMBASE, Medline, and Cochrane Library from inception through August 2021 for all randomized clinical trials in HFpEF (EF >40%) that evaluated beta-blockers, mineralocorticoid receptor antagonist (MRA), angiotensin-converting enzyme inhibitors (ACE), angiotensin receptor blockers (ARB), angiotensin receptor-neprilysin inhibitor (ARNI), and sodium-glucose cotransporter-2 inhibitors (SGLT2i). Outcomes assessed were cardiovascular mortality, all-cause mortality, and HF hospitalization. A frequentist network meta-analysis was performed with a random-effects model. We included 22 randomized clinical trials (30,673 participants; mean age = 71.7 ± 4.2 years; females = 49.3 ± 7.7%; median follow-up = 24.4 ± 11.1 months). Compared with placebo, there was no statistically significant difference in cardiovascular mortality [beta-blockers; odds ratio (OR) 0.79 (0.46–1.34), MRA; OR 0.90 (0.70–1.14), ACE OR 0.95 (0.59–1.53), ARB; OR 1.02 (0.87–1.19), ARNI; OR 0.97 (0.74–1.26) and SGLT2i; OR 1.00 (0.84–1.18)] or all-cause mortality [beta blockers; OR 0.75 (0.54–1.04), MRA; OR 0.90 (0.75–1.08) ACE; OR 1.05 (0.71–1.54), ARB; OR 1.03 (0.91–1.15), ARNI; OR 0.99 (0.82–1.20) and SGLT2i; OR 1.00 (0.89–1.13)]. The certainty in these estimates was low or very low. There was a significantly reduction in HF hospitalization with the use of SGLT2i [OR 0.71 (0.62–0.82), moderate certainty], ARNI [OR 0.77 (0.63–0.94), low certainty], and MRA [OR 0.81 (0.66–0.98), moderate certainty]; with corresponding P scores of 0.84, 0.68, and 0.58, respectively. In HFpEF, the use of beta-blockers, MRA, ACE/ARB/ARNI, or SGLT2i was not associated with improved cardiovascular or all-cause mortality. SGLT2i, ARNI, and MRA reduced the risk of HF hospitalizations.

AbstractBackgroundMore than 300 variants in the presenilin 1 (PSEN1), presenilin 2 (PSEN2), or amyloid precursor protein (APP) genes have been reported to cause Dominantly Inherited Alzheimer Disease (DIAD). However, most of these reports come from non‐Hispanic whites and the full extent of DIAD remains understudied in Latin American (LatAm) countries. Here we describe five AD affected families from LatAm carrying novel DIAD variants.MethodsFive novel variants in the presenilin1 (PSEN1) gene were identified in Brazilian (p.Val103_Ser104delinsGly, p.Lys395Ile, p.Pro264Se and p.Ala275Thr) and Mexican families (p.Ile414Thr). To assign the likelihood of pathogenicity among these variants of unknown significance, we report pedigree information, frequency in control populations, in silico predictions, and cell‐based models.ResultThe mean age at onset in newly identified families was 43.5 years (range 36‐54). The novel variants were absent from gnomAD genome and exome databases. Two PSEN1 variants (p.Val103_Ser104delinsGly and p.Lys395Ile) showed segregation with the disease status; segregation studies were not possible in the other three families. Additionally, PSEN1 p.Val103_Ser104delinsGly, p.Lys395Ile, p.Pro264Se, p.Ala275Thr produced Aβ profiles consistent with known AD pathogenic mutations (i.e. increased extracellular Aβ42/40); thus, we consider them as likely pathogenic. PSEN1 p.Ile414Thr did not alter Aβ in a manner consistent with a known pathogenic mutation; therefore, PSEN1 p.Ile414Thr likely represents an AD risk factor or benign polymorphism.ConclusionOur study provides further insights into the genetics of AD in LatAm by identifying novel DIAD pathogenic variants in Brazil and Mexico, two countries with distinct genetic admixtures. Expanding the families eligible to participate in observational and clinical trials of DIAD enhances the generalizability of diagnosis and treatment approaches.