The contributions of diverse cell populations in the human lung to pulmonary fibrosis pathogenesis are poorly understood. Single-cell RNA sequencing can reveal changes within individual cell ...populations during pulmonary fibrosis that are important for disease pathogenesis.
To determine whether single-cell RNA sequencing can reveal disease-related heterogeneity within alveolar macrophages, epithelial cells, or other cell types in lung tissue from subjects with pulmonary fibrosis compared with control subjects.
We performed single-cell RNA sequencing on lung tissue obtained from eight transplant donors and eight recipients with pulmonary fibrosis and on one bronchoscopic cryobiospy sample from a patient with idiopathic pulmonary fibrosis. We validated these data using
RNA hybridization, immunohistochemistry, and bulk RNA-sequencing on flow-sorted cells from 22 additional subjects.
We identified a distinct, novel population of profibrotic alveolar macrophages exclusively in patients with fibrosis. Within epithelial cells, the expression of genes involved in Wnt secretion and response was restricted to nonoverlapping cells. We identified rare cell populations including airway stem cells and senescent cells emerging during pulmonary fibrosis. We developed a web-based tool to explore these data.
We generated a single-cell atlas of pulmonary fibrosis. Using this atlas, we demonstrated heterogeneity within alveolar macrophages and epithelial cells from subjects with pulmonary fibrosis. These results support the feasibility of discovery-based approaches using next-generation sequencing technologies to identify signaling pathways for targeting in the development of personalized therapies for patients with pulmonary fibrosis.
Deregulation of signaling pathways is a hallmark of malignant transformation. Signaling-associated phosphoproteins can be degraded to generate cancer-specific phosphopeptides that are presented by ...major histocompatibility complex (MHC) class I and II molecules and recognized by T cells; however, the contribution of these phosphoprotein-specific T cells to immune surveillance is unclear. We identified 95 phosphopeptides presented on the surface of primary hematological tumors and normal tissues, including 61 that were tumor-specific. Phosphopeptides were more prevalent on more aggressive and malignant samples. CD8(+) T cell lines specific for these phosphopeptides recognized and killed both leukemia cell lines and human leukocyte antigen-matched primary leukemia cells ex vivo. Notably, healthy individuals showed robust CD8(+) T cell responses against many of these phosphopeptides within the circulating memory compartment. This immunity was significantly reduced or absent in some leukemia patients. This reduction correlated with clinical outcome; however, immunity was restored after allogeneic stem cell transplantation. These results suggest that phosphopeptides may be targets of cancer immune surveillance in humans, and point to their importance for development of vaccine-based and T cell adoptive transfer immunotherapies.
Determining the relative importance of sexual and asexual reproduction is critical for determining how genetic diversity is partitioned within and among populations. Macroalgae exhibit reproductive ...system variability, with many species capable of both sexual and asexual reproduction. Thus, rates of fragmentation (asexual) versus sporic recruitment (sexual) must be quantified. This is critical during range expansions when shifts to uniparental reproduction are common. Chondria tumulosa is a cryptogenic red alga that was discovered forming thick mats at Manawai, in the Northwestern Hawaiian Islands, during opportunistic sampling in 2019. It reduced the biodiversity and abundance of associated coral reef organisms. To characterize the reproductive system of C. tumulosa in this atoll, we visually assessed 124 thallus clumps for reproductive structures and used five microsatellite loci to genotype 41 thalli. All thalli bearing reproductive structures (20%) and all thalli that were genotyped were tetrasporophytes. No gametophytic thalli were observed using microscopy or microsatellite genotyping, though 80% of thalli observed under the microscope were vegetative. We observed in situ thallus fragmentation supported by the presence of 17 repeated genotypes and other genetic signatures, suggesting high rates of asexual reproduction. These results suggest that C. tumulosa is partially clonal in this atoll and has the potential for spreading to other nearby atolls. Rapid establishment, thallus fragmentation and tetrasporophytic dominance are consistent with other red macroalgal invasions studied to date. Understanding the reproductive system is an important component of developing management strategies for this alga and expanding our understanding of the population genetics of partially clonal taxa.
Reoperative bariatric surgery has become a common practice in many bariatric surgery programs. There is currently little evidence-based guidance regarding specific indications and outcomes for ...reoperative bariatric surgery. A task force was convened to review the current evidence regarding reoperative bariatric surgery. The aim of the review was to identify procedure-specific indications and outcomes for reoperative procedures.
Literature search was conducted to identify studies reporting indications for and outcomes after reoperative bariatric surgery. Specifically, operations to treat complications, failed weight loss, and weight regain were evaluated. Abstract and manuscript reviews were completed by the task force members to identify, grade, and categorize relevant studies.
A total of 819 articles were identified in the initial search. After review for inclusion criteria and data quality, 175 articles were included in the systematic review and analysis. The majority of published studies are single center retrospective reviews. The evidence supporting reoperative surgery for acute and chronic complications is described. The evidence regarding reoperative surgery for failed weight loss and weight regain generally demonstrates improved weight loss and co-morbidity reduction after reintervention. Procedure-specific outcomes are described. Complication rates are generally reported to be higher after reoperative surgery compared to primary surgery.
The indications and outcomes for reoperative bariatric surgery are procedure-specific but the current evidence does support additional treatment for persistent obesity, co-morbid disease, and complications.
Fanconi anemia (FA) is a rare genetic disorder characterized by bone marrow failure, congenital abnormalities, and an increased risk for cancer and leukemia. Components of the FA-BRCA pathway are ...thought to function in the repair of DNA interstrand cross-links. Central to this pathway is the monoubiquitylation and chromatin localization of 2 FA proteins, FA complementation group D2 (FANCD2) and FANCI. In the present study, we show that RAD18 binds FANCD2 and is required for efficient monoubiquitylation and chromatin localization of both FANCD2 and FANCI. Human RAD18-knockout cells display increased sensitivity to mitomycin C and a delay in FANCD2 foci formation compared with their wild-type counterparts. In addition, RAD18-knockout cells display a unique lack of FANCD2 and FANCI localization to chromatin in exponentially growing cells. FANCD2 ubiquitylation is normal in cells containing a ubiquitylation-resistant form of proliferating cell nuclear antigen, and chromatin loading of FA core complex proteins appears normal in RAD18-knockout cells. Mutation of the RING domain of RAD18 ablates the interaction with and chromatin loading of FANCD2. These data suggest a key role for the E3 ligase activity of RAD18 in the recruitment of FANCD2 and FANCI to chromatin and the events leading to their ubiquitylation during S phase.
Patients post-bidirectional Glenn (BDG) operation are at risk of left and right pulmonary artery (LPA and RPA) hypoplasia. Transthoracic echocardiograms (TTE) in active children can miss essential ...elements of anatomy. Procedural sedation improves image quality but increases risk of adverse events. We hypothesized that echocardiograms performed with sedation in patients post-BDG would improve visualization of branch pulmonary arteries with minimal adverse events. Patients post-BDG between 2007–2016 were identified. Exclusion criteria were > 12 months of age, absence of complete TTE before discharge, death before discharge, conversion to shunt physiology, and prolonged post-operative course > 7 weeks. Of 254 post-BDG patients, 153 met inclusion/exclusion criteria. TTE reports were reviewed for visualization of LPA/RPA and hypoplasia of LPA/RPA. Blinded assessment of image quality was performed (scale of 1poor to 5excellent). Pertinent clinical data were recorded. Pearson’s chi-squared and Wilcoxon Rank Sum tests used for statistical analysis. The median age at surgery and hospital stay were 4.8 months and 10 days. Twenty-three patients underwent sedated TTE (15%). Sedated TTE significantly improved visualization of the RPA (100% vs 82%,
p
= 0.029) and LPA, though this did not reach statistical significance (100% vs 91%,
p
= 0.129). Sedated TTEs has significantly better image quality (median of 4 vs 3,
p
< 0.001). There were no serious adverse events due to sedation. Sedated TTE early post-BDG is safe, improves visualization of the RPA and LPA, and improves overall image quality. Routine sedated TTE in these patients should be considered. Implications for long-term outcome need to be further analyzed.
The prefrontal cortex of the primate frontal lobes provides the capacity for judgment which can constantly adapt behavior in order to optimize its outcome. Adjudicating between long-term memory ...programs and prepotent responses, this capacity reviews all incoming information and provides an interpretation dependent on the events that have just occurred, the events that are predicted to happen, and the alternative response strategies that are available in the given situation. It has been theorized that this function requires two essential integrated components, a central executive which guides selective attention based on mechanisms of associative memory, as well as the second component, working memory buffers, in which information is held online, abstracted, and translated on a mental sketchpad of work in progress. In this review, we critically outline the evidence that the integration of these processes and, in particular, the induction and maintenance of persistent activity in prefrontal cortex and related networks, is dependent upon the interaction of dopamine D1 and glutamate NMDA receptor signaling at critical nodes within local circuits and distributed networks. We argue that this interaction is not only essential for representational memory, but also core to mechanisms of neuroadaptation and learning. Understanding its functional significance promises to reveal major new insights into prefrontal dysfunction in schizophrenia and, hence, to target a new generation of drugs designed to ameliorate the debilitating working memory deficits in this disorder.
The elevation of kynurenic acid (KYNA) observed in schizophrenic patients may contribute to core symptoms arising from glutamate hypofunction, including cognitive impairments. Although increased KYNA ...levels reduce excitatory neurotransmission, KYNA has been proposed to act as an endogenous antagonist at the glycine site of the glutamate NMDA receptor (NMDAR) and as a negative allosteric modulator at the α7 nicotinic acetylcholine receptor. Levels of KYNA are elevated in CSF and the postmortem brain of schizophrenia patients, and these elevated levels of KYNA could contribute to NMDAR hypofunction and the cognitive deficits and negative symptoms associated with this disease. However, the impact of endogenously produced KYNA on brain function and behavior is less well understood due to a paucity of pharmacological tools. To address this issue, we identified PF-04859989, a brain-penetrable inhibitor of kynurenine aminotransferase II (KAT II), the enzyme responsible for most brain KYNA synthesis. In rats, systemic administration of PF-04859989 dose-dependently reduced brain KYNA to as little as 28% of basal levels, and prevented amphetamine- and ketamine-induced disruption of auditory gating and improved performance in a sustained attention task. It also prevented ketamine-induced disruption of performance in a working memory task and a spatial memory task in rodents and nonhuman primates, respectively. Together, these findings support the hypotheses that endogenous KYNA impacts cognitive function and that inhibition of KAT II, and consequent lowering of endogenous brain KYNA levels, improves cognitive performance under conditions considered relevant for schizophrenia.
Management of hypertension, dyslipidemia, diabetes and other modifiable factors may mitigate the cardiovascular disease (CVD) risk in people with human immunodeficiency virus (HIV, PWH) compared with ...people without HIV (PWoH).
This was a retrospective cohort study of 8285 PWH and 170 517 PWoH from an integrated health system. Risk factor control was measured using a novel disease management index (DMI) accounting for amount/duration above treatment goals (0% to 100% perfect control), including 2 DMIs for hypertension (diastolic and systolic blood pressure), 3 for dyslipidemia (low-density lipoprotein, total cholesterol, triglycerides), and 1 for diabetes (HbA1c). CVD risk by HIV status was evaluated overall and in subgroups defined by DMIs, smoking, alcohol use, and overweight/obesity in adjusted Cox proportional hazards models.
PWH and PWoH had similar DMIs (80%-100%) except for triglycerides (worse for PWH) and HbA1c (better for PWH). In adjusted models, PWH had an elevated risk of CVD compared with PWoH (hazard ratio HR, 1.18; 95% confidence interval CI, 1.07-1.31). This association was attenuated in subgroups with controlled dyslipidemia and diabetes but remained elevated for PWH with controlled hypertension or higher total cholesterol. The strongest HIV status association with CVD was seen in the subgroup with frequent unhealthy alcohol use (HR, 2.13; 95% CI, 1.04-4.34).
Control of dyslipidemia and diabetes, but not hypertension, attenuated the HIV status association with CVD. The strong association of HIV and CVD with frequent unhealthy alcohol use suggests enhanced screening and treatment of alcohol problems in PWH is warranted.
Rationale
Dopamine (DA) signaling through the D1 receptor has been shown to be integral to multiple aspects of cognition, including the core process of working memory. The discovery of positive ...allosteric modulators (PAMs) of the D1 receptor has enabled treatment modalities that may have alternative benefits to orthosteric D1 agonists arising from a synergism of action with functional D1 receptor signaling.
Objectives
To investigate this potential, we have studied the effects of the novel D1 PAM DPTQ on a spatial delayed response working memory task in the rhesus monkey. Initial studies indicated that DPTQ binds to primate D1R with high affinity and selectivity and elevates spontaneous eye blink rate in rhesus monkeys in a dose-dependent manner consistent with plasma ligand exposures and central D1activation.
Results
Based on those results, DPTQ was tested at 2.5 mg/kg IM in the working memory task. No acute effect was observed 1 h after dosing, but performance was impaired 48 h later. Remarkably, this deficit was immediately followed by a significant enhancement in cognition over the next 3 days. In a second experiment in which DPTQ was administered on days 1 and 5, the early impairment was smaller and did not reach statistical significance, but statistically significant enhancement of performance was observed over the following week. Lower doses of 0.1 and 1.0 mg/kg were also capable of producing this protracted enhancement without inducing any transient impairment.
Conclusions
DPTQ exemplifies a class of D1PAMs that may be capable of providing long-term improvements in working memory.
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