Comparing Racial Differences in Emphysema Prevalence Among Adults With Normal Spirometry: A Secondary Data Analysis of the CARDIA Lung Study.

BACKGROUND: Computed tomography (CT) imaging complements spirometry and may provide insight into racial disparities in respiratory health. OBJECTIVE: To determine the difference in emphysema prevalence between Black and White adults with different measures of normal spirometry results. DESIGN: Observational study using clinical data and spirometry from the CARDIA (Coronary Artery Risk Development in Young Adults) study obtained in 2015 to 2016 and CT scans done in 2010 to 2011. SETTING: 4 U.S. centers. PARTICIPANTS: Population-based sample of Black and White adults. MEASUREMENTS: Self-identified race and visually identified emphysema on CT in participants with different measures of "normal" spirometry results, calculated using standard race-specific and race-neutral reference equations. RESULTS: A total of 2674 participants (485 Black men, 762 Black women, 659 White men, and 768 White women) had both a CT scan and spirometry available for analysis. Among participants with a race-specific FEV1 between 80% and 99% of predicted, 6.5% had emphysema. In this group, emphysema prevalence was 3.9-fold (95% CI, 2.1- to 7.1-fold; 15.5% vs. 4.0%) higher among Black men than White men and 1.9-fold (CI, 1.0- to 3.8-fold; 6.6% vs. 3.4%) higher among Black women than White women. Among participants with a race-specific FEV1 between 100% and 120% of predicted, 4.0% had emphysema. In this category, Black men had a 6.4-fold (CI, 2.2- to 18.7-fold; 13.9% vs. 2.2%) higher prevalence of emphysema than White men, whereas Black and White women had a similar prevalence of emphysema (2.6% and 2.0%, respectively). The use of race-neutral equations to identify participants with an FEV1 percent predicted between 80% and 120% attenuated racial differences in emphysema prevalence among men and eliminated racial differences among women. LIMITATION: No CT scans were obtained during the most recent study visit (2015 to 2016) when spirometry was done. CONCLUSION: Emphysema is often present before spirometry findings become abnormal, particularly among Black men. Reliance on spirometry alone to differentiate lung health from lung disease may result in the underrecognition of impaired respiratory health and exacerbate racial disparities. PRIMARY FUNDING SOURCE: National Institutes of Health.

CD73-mediated adenosine production promotes stem cell-like properties in mouse Tc17 cells.

The CD73 ectonucleotidase catalyses the hydrolysis of AMP to adenosine, an immunosuppressive molecule. Recent evidence has demonstrated that this ectonucleotidase is up-regulated in T helper type 17 cells when generated in the presence of transforming growth factor-ß (TGF-ß), and hence CD73 expression is related to the acquisition of immunosuppressive potential by these cells. TGF-ß is also able to induce CD73 expression in CD8(+) T cells but the function of this ectonucleotidase in CD8(+) T cells is still unknown. Here, we show that Tc17 cells present high levels of the CD73 ectonucleotidase and produce adenosine; however, they do not suppress the proliferation of CD4(+) T cells. Interestingly, we report that adenosine signalling through A2A receptor favours interleukin-17 production and the expression of stem cell-associated transcription factors such as tcf-7 and lef-1 but restrains the acquisition of Tc1-related effector molecules such as interferon-γ and Granzyme B by Tc17 cells. Within the tumour microenvironment, CD73 is highly expressed in CD62L(+) CD127(+) CD8(+) T cells (memory T cells) and is down-regulated in GZMB(+) KLRG1(+) CD8(+) T cells (terminally differentiated T cells), demonstrating that CD73 is expressed in memory/naive cells and is down-regulated during differentiation. These data reveal a novel function of CD73 ectonucleotidase in arresting CD8(+) T-cell differentiation and support the idea that CD73-driven adenosine production by Tc17 cells may promote stem cell-like properties in Tc17 cells.

A functional N-terminal domain in C/EBPß-LAP* is required for interacting with SWI/SNF and to repress Ric-8B gene transcription in osteoblasts.

The chromatin remodeling complex SWI/SNF and the transcription factor C/EBPß play critical roles in osteoblastic cells as they jointly control transcription of a number of bone-related target genes. The largest C/EBPß isoform, LAP*, possesses a short additional N-terminal domain that has been proposed to mediate the interaction of this factor with SWI/SNF in myeloid cells. Here we examine the requirement of a functional N-terminus in C/EBPß-LAP* for binding SWI/SNF and for recruiting this complex to the Ric-8B gene to mediate transcriptional repression. We find that both C/EBPß-LAP* and SWI/SNF simultaneously bind to the Ric-8B promoter in differentiating osteoblasts that repress Ric-8B expression. This decreased expression of Ric-8B is not accompanied by significant changes in histone acetylation at the Ric-8B gene promoter sequence. A single aminoacid change at the C/EBPß-LAP* N-terminus (R3L) that inhibits C/EBPß-LAP*-SWI/SNF interaction, also prevents SWI/SNF recruitment to the Ric-8B promoter as well as C/EBPß-LAP*-dependent repression of the Ric-8B gene. Inducible expression of the C/EBPß-LAP*R3L protein in stably transfected osteoblastic cells demonstrates that this mutant protein binds to C/EBPß-LAP*-target promoters and competes with the endogenous C/EBPß factor. Together our results indicate that a functional N-terminus in C/EBPß-LAP* is required for interacting with SWI/SNF and for Ric-8B gene repression in osteoblasts.

Associations Between Coronary Artery Calcium Score and Exacerbation Risk in BLOCK-COPD.

Introduction: In 2019, the Beta-Blockers for the Prevention of Acute Exacerbations of Chronic Obstructive Pulmonary Disease study (BLOCK-COPD) evaluated the effect of metoprolol on exacerbation risk and mortality in a COPD population without indications for beta-blocker use. We hypothesized that an imaging metric of coronary artery disease (CAD), the coronary artery calcium (CAC) score, would predict exacerbation risk and identify a differential response to metoprolol treatment. Methods: The study population includes participants in the BLOCK-COPD study from multiple study sites. Participants underwent clinically indicated thoracic computed tomography (CT) scans ± 12 months from enrollment. The Weston scoring system quantified CAC. Adjusted Cox proportional hazards models evaluated for associations between CAC and time to exacerbation. Results: Data is included for 109 participants. The mean CAC score was 5.1±3.7, and 92 participants (84%) had CAC scores greater than 0. Over a median (interquartile range) follow-up time of 350 (280 to 352) days, there were 61 mild exacerbations and 19 severe/very severe exacerbations. No associations were found between exacerbations of any severity and CAC>0 or total CAC. Associations were observed between total CAC and CAC>0 in the left circumflex (LCx) and time to exacerbation of any severity (adjusted hazard ratio [aHR]=1.39, confidence interval [CI]: 1.08-1.79, p=0.01) and (aHR=1.96, 95% CI: 1.04-3.70, p=0.04), respectively. Conclusions: CAD is a prevalent comorbidity in COPD accounting for significant mortality. Our study confirms the high prevalence of CAD using the CAC score; however, we did not discover an association between CAC and exacerbation risk. We did find novel associations between CAC in the LCx and exacerbation risk which warrant further investigation in larger cohorts.

Neighborhood Socioeconomic Deprivation in Young Adulthood and Future Respiratory Health: The CARDIA Lung Study.

PURPOSE: There are limited data on the relationship between neighborhood level factors and their association with lung health independent of individual socioeconomic status. We sought to determine whether baseline neighborhood level socioeconomic deprivation in young adults is associated with greater 20-year decline in lung function and higher risk of future lung disease, independent of baseline individual income, education, and smoking status. METHODS: This multicenter population-based cohort study included 2689 participants in Coronary Artery Risk Development in Young Adults (CARDIA) for whom neighborhood deprivation was determined at year 10 (baseline for study) and who had complete lung function measurements at years 10 and 30. Baseline neighborhood deprivation was defined using 1990 Census blocks as a combination of 4 factors involving median household income, poverty level, and educational achievement. The outcomes were decline in lung function over 20 years (year 10 to 30) and odds of emphysema (year 25). RESULTS: In multivariable regression models, greater baseline neighborhood deprivation was associated with greater decline in lung function (-2.34 mL/year excess annual decline in forced expiratory volume in 1 second (FEV1) in the highest versus lowest deprivation quartile (P = .014)). Furthermore, baseline neighborhood deprivation was independently associated with greater odds of emphysema (odds ratio [OR] 2.99, 95% confidence interval [CI] 1.42-6.30). CONCLUSIONS: Residence in neighborhoods with greater socioeconomic deprivation in young adulthood, independent of individual income and smoking, is associated with greater 20-year decline in forced expiratory volume in 1 second and higher risk of future emphysema.

Differentiation of adipose-derived stem cells to functional CD105neg CD73low melanocyte precursors guided by defined culture condition.

BACKGROUND: The generation of functional human epidermal melanocytes (HEM) from stem cells provides an unprecedented source for cell-based therapy in vitiligo. Despite the important efforts exerted to obtain melanin-producing cells from stem cells, pre-clinical results still lack the safety and scalability characteristics essential for their translational application. METHODS: Here, we report a rapid and efficient protocol based on defined culture conditions capable of differentiating adult adipose-derived stem cells (ADSC) to scalable amounts of proliferative melanocyte precursors (PreMel) within 30 days. PreMel were characterized in vitro through qPCR, Western blot, flow cytometry, biochemical assays, and in vivo assays in immunocompromised mice (NOD.Cg-Prkdcscid Il2rgtm1Wjl/SzJ, or NSG). RESULTS: After 30 days of differentiation, the stem cell-derived PreMel were defined as CD105neg CD73low according to immunophenotypic changes in comparison with parental stem cell markers. In addition, expression of microphthalmia-associated transcription factor (MITF), active tyrosinase (TYR), and the terminal differentiation-involved premelanosome protein (PMEL) were detected. Furthermore, PreMel had the potential to synthesize melanin and package it into melanosomes both in vitro and in vivo in NSG mice skin. CONCLUSIONS: This study proposes a rapid and scalable protocol for the generation of proliferative melanocyte precursors (PreMel) from ADSC. These PreMel display the essential functional characteristics of bona fide HEM, opening a new path for an autologous cellular therapy for vitiligo patients.

Netrin-1 acts as a non-canonical angiogenic factor produced by human Wharton's jelly mesenchymal stem cells (WJ-MSC).

BACKGROUND: Angiogenesis, the process in which new blood vessels are formed from preexisting ones, is highly dependent on the presence of classical angiogenic factors. Recent evidence suggests that axonal guidance proteins and their receptors can also act as angiogenic regulators. Netrin, a family of laminin-like proteins, specifically Netrin-1 and 4, act via DCC/Neogenin-1 and UNC5 class of receptors to promote or inhibit angiogenesis, depending on the physiological context. METHODS: Mesenchymal stem cells secrete a broad set of classical angiogenic factors. However, little is known about the expression of non-canonical angiogenic factors such as Netrin-1. The aim was to characterize the possible secretion of Netrin ligands by Wharton's jelly-derived mesenchymal stem cells (WJ-MSC). We evaluated if Netrin-1 presence in the conditioned media from these cells was capable of inducing angiogenesis both in vitro and in vivo, using human umbilical vein endothelial cells (HUVEC) and chicken chorioallantoic membrane (CAM), respectively. In addition, we investigated if the RhoA/ROCK pathway is responsible for the integration of Netrin signaling to control vessel formation. RESULTS: The paracrine angiogenic effect of the WJ-MSC-conditioned media is mediated at least in part by Netrin-1 given that pharmacological blockage of Netrin-1 in WJ-MSC resulted in diminished angiogenesis on HUVEC. When HUVEC were stimulated with exogenous Netrin-1 assayed at physiological concentrations (10-200 ng/mL), endothelial vascular migration occurred in a concentration-dependent manner. In line with our determination of Netrin-1 present in WJ-MSC-conditioned media we were able to obtain endothelial tubule formation even in the pg/mL range. Through CAM assays we validated that WJ-MSC-secreted Netrin-1 promotes an increased angiogenesis in vivo. Netrin-1, secreted by WJ-MSC, might mediate its angiogenic effect through specific cell surface receptors on the endothelium, such as UNC5b and/or integrin α6ß1, expressed in HUVEC. However, the angiogenic response of Netrin-1 seems not to be mediated through the RhoA/ROCK pathway. CONCLUSIONS: Thus, here we show that stromal production of Netrin-1 is a critical component of the vascular regulatory machinery. This signaling event may have deep implications in the modulation of several processes related to a number of diseases where angiogenesis plays a key role in vascular homeostasis.

Transient rapamycin treatment can increase lifespan and healthspan in middle-aged mice.

The FDA approved drug rapamycin increases lifespan in rodents and delays age-related dysfunction in rodents and humans. Nevertheless, important questions remain regarding the optimal dose, duration, and mechanisms of action in the context of healthy aging. Here we show that 3 months of rapamycin treatment is sufficient to increase life expectancy by up to 60% and improve measures of healthspan in middle-aged mice. This transient treatment is also associated with a remodeling of the microbiome, including dramatically increased prevalence of segmented filamentous bacteria in the small intestine. We also define a dose in female mice that does not extend lifespan, but is associated with a striking shift in cancer prevalence toward aggressive hematopoietic cancers and away from non-hematopoietic malignancies. These data suggest that a short-term rapamycin treatment late in life has persistent effects that can robustly delay aging, influence cancer prevalence, and modulate the microbiome.

Purinergic Signaling as a Regulator of Th17 Cell Plasticity.

T helper type 17 (Th17) lymphocytes, characterized by the production of interleukin-17 and other pro-inflammatory cytokines, are present in intestinal lamina propria and have been described as important players driving intestinal inflammation. Recent evidence, supporting the notion of a functional and phenotypic instability of Th17 cells, has shown that Th17 differentiate into type 1 regulatory (Tr1) T cells during the resolution of intestinal inflammation. Moreover, it has been suggested that the expression of CD39 ectonucleotidase endows Th17 cells with immunosuppressive properties. However, the exact role of CD39 ectonucleotidase in Th17 cells has not been studied in the context of intestinal inflammation. Here we show that Th17 cells expressing CD39 ectonucleotidase can hydrolyze ATP and survive to ATP-induced cell death. Moreover, in vitro-generated Th17 cells expressing the CD39 ectonucleotidase produce IL-10 and are less pathogenic than CD39 negative Th17 cells in a model of experimental colitis in Rag-/- mice. Remarkably, we show that CD39 activity regulates the conversion of Th17 cells to IL-10-producing cells in vitro, which is abrogated in the presence of ATP and the CD39-specific inhibitor ARL67156. All these data suggest that CD39 expression by Th17 cells allows the depletion of ATP and is crucial for IL-10 production and survival during the resolution of intestinal inflammation.

Beyond reward prediction errors: the role of dopamine in movement kinematics.

We recorded activity of dopamine (DA) neurons in the substantia nigra pars compacta in unrestrained mice while monitoring their movements with video tracking. Our approach allows an unbiased examination of the continuous relationship between single unit activity and behavior. Although DA neurons show characteristic burst firing following cue or reward presentation, as previously reported, their activity can be explained by the representation of actual movement kinematics. Unlike neighboring pars reticulata GABAergic output neurons, which can represent vector components of position, DA neurons represent vector components of velocity or acceleration. We found neurons related to movements in four directions-up, down, left, right. For horizontal movements, there is significant lateralization of neurons: the left nigra contains more rightward neurons, whereas the right nigra contains more leftward neurons. The relationship between DA activity and movement kinematics was found on both appetitive trials using sucrose and aversive trials using air puff, showing that these neurons belong to a velocity control circuit that can be used for any number of purposes, whether to seek reward or to avoid harm. In support of this conclusion, mimicry of the phasic activation of DA neurons with selective optogenetic stimulation could also generate movements. Contrary to the popular hypothesis that DA neurons encode reward prediction errors, our results suggest that nigrostriatal DA plays an essential role in controlling the kinematics of voluntary movements. We hypothesize that DA signaling implements gain adjustment for adaptive transition control, and describe a new model of the basal ganglia (BG) in which DA functions to adjust the gain of the transition controller. This model has significant implications for our understanding of movement disorders implicating DA and the BG.

A wireless multi-channel recording system for freely behaving mice and rats.

To understand the neural basis of behavior, it is necessary to record brain activity in freely moving animals. Advances in implantable multi-electrode array technology have enabled researchers to record the activity of neuronal ensembles from multiple brain regions. The full potential of this approach is currently limited by reliance on cable tethers, with bundles of wires connecting the implanted electrodes to the data acquisition system while impeding the natural behavior of the animal. To overcome these limitations, here we introduce a multi-channel wireless headstage system designed for small animals such as rats and mice. A variety of single unit and local field potential signals were recorded from the dorsal striatum and substantia nigra in mice and the ventral striatum and prefrontal cortex simultaneously in rats. This wireless system could be interfaced with commercially available data acquisition systems, and the signals obtained were comparable in quality to those acquired using cable tethers. On account of its small size, light weight, and rechargeable battery, this wireless headstage system is suitable for studying the neural basis of natural behavior, eliminating the need for wires, commutators, and other limitations associated with traditional tethered recording systems.