Morphogen gradient scaling by recycling of intracellular Dpp.

Morphogen gradients are fundamental to establish morphological patterns in developing tissues1. During development, gradients scale to remain proportional to the size of growing organs2,3. Scaling is a universal gear that adjusts patterns to size in living organisms3-8, but its mechanisms remain unclear. Here, focusing on the Decapentaplegic (Dpp) gradient in the Drosophila wing disc, we uncover a cell biological basis behind scaling. From small to large discs, scaling of the Dpp gradient is achieved by increasing the contribution of the internalized Dpp molecules to Dpp transport: to expand the gradient, endocytosed molecules are re-exocytosed to spread extracellularly. To regulate the contribution of endocytosed Dpp to the spreading extracellular pool during tissue growth, it is the Dpp binding rates that are progressively modulated by the extracellular factor Pentagone, which drives scaling. Thus, for some morphogens, evolution may act on endocytic trafficking to regulate the range of the gradient and its scaling, which could allow the adaptation of shape and pattern to different sizes of organs in different species.

Population snapshots predict early haematopoietic and erythroid hierarchies.

The formation of red blood cells begins with the differentiation of multipotent haematopoietic progenitors. Reconstructing the steps of this differentiation represents a general challenge in stem-cell biology. Here we used single-cell transcriptomics, fate assays and a theory that allows the prediction of cell fates from population snapshots to demonstrate that mouse haematopoietic progenitors differentiate through a continuous, hierarchical structure into seven blood lineages. We uncovered coupling between the erythroid and the basophil or mast cell fates, a global haematopoietic response to erythroid stress and novel growth factor receptors that regulate erythropoiesis. We defined a flow cytometry sorting strategy to purify early stages of erythroid differentiation, completely isolating classically defined burst-forming and colony-forming progenitors. We also found that the cell cycle is progressively remodelled during erythroid development and during a sharp transcriptional switch that ends the colony-forming progenitor stage and activates terminal differentiation. Our work showcases the utility of linking transcriptomic data to predictive fate models, and provides insights into lineage development in vivo.

IQCELL: A platform for predicting the effect of gene perturbations on developmental trajectories using single-cell RNA-seq data.

The increasing availability of single-cell RNA-sequencing (scRNA-seq) data from various developmental systems provides the opportunity to infer gene regulatory networks (GRNs) directly from data. Herein we describe IQCELL, a platform to infer, simulate, and study executable logical GRNs directly from scRNA-seq data. Such executable GRNs allow simulation of fundamental hypotheses governing developmental programs and help accelerate the design of strategies to control stem cell fate. We first describe the architecture of IQCELL. Next, we apply IQCELL to scRNA-seq datasets from early mouse T-cell and red blood cell development, and show that the platform can infer overall over 74% of causal gene interactions previously reported from decades of research. We will also show that dynamic simulations of the generated GRN qualitatively recapitulate the effects of known gene perturbations. Finally, we implement an IQCELL gene selection pipeline that allows us to identify candidate genes, without prior knowledge. We demonstrate that GRN simulations based on the inferred set yield results similar to the original curated lists. In summary, the IQCELL platform offers a versatile tool to infer, simulate, and study executable GRNs in dynamic biological systems.

High-throughput micropatterning platform reveals Nodal-dependent bisection of peri-gastrulation-associated versus preneurulation-associated fate patterning.

In vitro models of postimplantation human development are valuable to the fields of regenerative medicine and developmental biology. Here, we report characterization of a robust in vitro platform that enabled high-content screening of multiple human pluripotent stem cell (hPSC) lines for their ability to undergo peri-gastrulation-like fate patterning upon bone morphogenetic protein 4 (BMP4) treatment of geometrically confined colonies and observed significant heterogeneity in their differentiation propensities along a gastrulation associable and neuralization associable axis. This cell line-associated heterogeneity was found to be attributable to endogenous Nodal expression, with up-regulation of Nodal correlated with expression of a gastrulation-associated gene profile, and Nodal down-regulation correlated with a preneurulation-associated gene profile expression. We harness this knowledge to establish a platform of preneurulation-like fate patterning in geometrically confined hPSC colonies in which fates arise because of a BMPs signalling gradient conveying positional information. Our work identifies a Nodal signalling-dependent switch in peri-gastrulation versus preneurulation-associated fate patterning in hPSC cells, provides a technology to robustly assay hPSC differentiation outcomes, and suggests conserved mechanisms of organized fate specification in differentiating epiblast and ectodermal tissues.

Sedation Usage in COVID-19 Acute Respiratory Distress Syndrome: A Multicenter Study.

BACKGROUND: Patients with COVID-19 acute respiratory distress syndrome (ARDS) have been shown to have high sedation requirements. OBJECTIVE: The purpose of this study was to compare sedative use between patients with COVID-19 ARDS and non-COVID-19 ARDS. METHODS: This was a retrospective study of patients with COVID-19 ARDS compared with historical controls of non-COVID-19 ARDS who were admitted to 2 hospitals from March 1, 2020, to April 30, 2020, and April 1, 2018, to December 31, 2019, respectively. The primary outcome was median cumulative dose of propofol (µg/kg) at 24 hours after intubation. RESULTS: There were 92 patients with COVID-19 ARDS and 37 patients with non-COVID-19 ARDS included. Within the first 24 hours of intubation, patients with COVID-19 ARDS required higher total median doses of propofol: 51 045 µg/kg (interquartile range, 26 150-62 365 µg/kg) versus 33 350 µg/kg (9632-51 455 µg/kg; P = 0.004). COVID-19 patients were more likely receive intravenous lorazepam (37% vs 14%; P = 0.02) and higher cumulative median doses of midazolam by days 5 (14 vs 4 mg; P = 0.04) and 7 of intubation (89 vs 4 mg; P = 0.03) to achieve the same median Richmond Analgesia-Sedation Scale scores. COVID-19 ARDS patients required more ventilator days (10 vs 6 days; P = 0.02). There was no difference in 30-day mortality. CONCLUSION AND RELEVANCE: Patients with COVID-19 ARDS required higher doses of propofol and benzodiazepines than patients with non-COVID-19 ARDS to achieve the same median levels of sedation.

Growth control in the Drosophila eye disc by the cytokine Unpaired.

A fundamental question in developmental biology is how organ size is controlled. We have previously shown that the area growth rate in the Drosophila eye primordium declines inversely proportionally to the increase in its area. How the observed reduction in the growth rate is achieved is unknown. Here, we explore the dilution of the cytokine Unpaired (Upd) as a possible candidate mechanism. In the developing eye, upd expression is transient, ceasing at the time when the morphogenetic furrow first emerges. We confirm experimentally that the diffusion and stability of the JAK/STAT ligand Upd are sufficient to control eye disc growth via a dilution mechanism. We further show that sequestration of Upd by ectopic expression of an inactive form of the receptor Domeless (Dome) results in a substantially lower growth rate, but the area growth rate still declines inversely proportionally to the area increase. This growth rate-to-area relationship is no longer observed when Upd dilution is prevented by the continuous, ectopic expression of Upd. We conclude that a mechanism based on the dilution of the growth modulator Upd can explain how growth termination is controlled in the eye disc.

Pharmacist Presence Decreases Time to Prothrombin Complex Concentrate in Emergency Department Patients with Life-Threatening Bleeding and Urgent Procedures.

BACKGROUND: Reversal of anticoagulation with four-factor prothrombin complex concentrate (4F-PCC) is critical, yet the optimal timing to 4F-PCC administration and whether quicker administration improves hemostasis remains unknown. OBJECTIVE: The objective of this study was to determine if pharmacist presence is predictive of faster time to 4F-PCC. METHODS: This retrospective cohort study included patients receiving 4F-PCC for life-threatening bleeding or urgent procedure in the emergency department (ED) from 2014 to 2018. Patients with pharmacists at bedside (PharmD group) were compared with physician teams alone (control group). The primary outcome was time from ED presentation to 4F-PCC administration. RESULTS: Of 252 patients evaluated, 116 patients (46%) were included (n = 50 PharmD group; n = 66 control group). Most patients presented on warfarin (68.1%), and of the life-threatening bleeds (94%), intracranial hemorrhage was most common (67.2%). The median time to 4F-PCC administration was significantly shorter in the PharmD group (66.5 vs. 206.5 min, p < 0.001). Pharmacist at bedside was the only factor independently associated with reduction in time to 4F-PCC (ß coefficient -163.5 min, 95% confidence interval -249.4 to -77.7). Although there was no difference in hemostasis or mortality, patients in the PharmD group had a shorter intensive care unit length of stay (LOS) (2 vs. 5 days, p < 0.01) and hospital LOS (5.5 vs. 8 days, p = 0.02). CONCLUSION: A pharmacist at the bedside of patients who present to the ED with life-threatening bleeding or need for emergent procedure decreased time to 4F-PCC administration by 140 min, even after accounting for confounders. Faster time to 4F-PCC was associated with significantly shorter intensive care unit and hospital LOS.

Critical Point in Self-Organized Tissue Growth.

We present a theory of pattern formation in growing domains inspired by biological examples of tissue development. Gradients of signaling molecules regulate growth, while growth changes these graded chemical patterns by dilution and advection. We identify a critical point of this feedback dynamics, which is characterized by spatially homogeneous growth and proportional scaling of patterns with tissue length. We apply this theory to the biological model system of the developing wing of the fruit fly Drosophila melanogaster and quantitatively identify signatures of the critical point.

Increased avidity for Dpp/BMP2 maintains the proliferation of progenitors-like cells in the Drosophila eye.

During organ development, the progenitor state is transient, and depends on specific combinations of transcription factors and extracellular signals. Not surprisingly, abnormal maintenance of progenitor transcription factors may lead to tissue overgrowth, and the concurrence of signals from the local environment is often critical to trigger this overgrowth. Therefore, identifying specific combinations of transcription factors/signals promoting -or opposing- proliferation in progenitors is essential to understand normal development and disease. We have investigated this issue using the Drosophila eye as model. Transcription factors hth and tsh are transiently expressed in eye progenitors causing the expansion of the progenitor pool. However, if their co-expression is maintained experimentally, cell proliferation continues and differentiation is halted. Here we show that Hth+Tsh-induced tissue overgrowth requires the BMP2 Dpp and the abnormal hyperactivation of its pathway. Rather than using autocrine Dpp expression, Hth+Tsh cells increase their avidity for Dpp, produced locally, by upregulating extracellular matrix components. During normal development, Dpp represses hth and tsh ensuring that the progenitor state is transient. However, cells in which Hth+Tsh expression is forcibly maintained use Dpp to enhance their proliferation.

A Model of the Spatio-temporal Dynamics of Drosophila Eye Disc Development.

Patterning and growth are linked during early development and have to be tightly controlled to result in a functional tissue or organ. During the development of the Drosophila eye, this linkage is particularly clear: the growth of the eye primordium mainly results from proliferating cells ahead of the morphogenetic furrow (MF), a moving signaling wave that sweeps across the tissue from the posterior to the anterior side, that induces proliferating cells anterior to it to differentiate and become cell cycle quiescent in its wake. Therefore, final eye disc size depends on the proliferation rate of undifferentiated cells and on the speed with which the MF sweeps across the eye disc. We developed a spatio-temporal model of the growing eye disc based on the regulatory interactions controlled by the signals Decapentaplegic (Dpp), Hedgehog (Hh) and the transcription factor Homothorax (Hth) and explored how the signaling patterns affect the movement of the MF and impact on eye disc growth. We used published and new quantitative data to parameterize the model. In particular, two crucial parameter values, the degradation rate of Hth and the diffusion coefficient of Hh, were measured. The model is able to reproduce the linear movement of the MF and the termination of growth of the primordium. We further show that the model can explain several mutant phenotypes, but fails to reproduce the previously observed scaling of the Dpp gradient in the anterior compartment.

Short communication: Discrimination between retail bovine milks with different fat contents using chemometrics and fatty acid profiling.

We used a multivariate chemometric approach to differentiate or associate retail bovine milks with different fat contents and non-dairy beverages, using fatty acid profiles and statistical analysis. We collected samples of bovine milk (whole, semi-skim, and skim; n = 62) and non-dairy beverages (n = 27), and we analyzed them using gas-liquid chromatography. Principal component analysis of the fatty acid data yielded 3 significant principal components, which accounted for 72% of the total variance in the data set. Principal component 1 was related to saturated fatty acids (C4:0, C6:0, C8:0, C12:0, C14:0, C17:0, and C18:0) and monounsaturated fatty acids (C14:1 cis-9, C16:1 cis-9, C17:1 cis-9, and C18:1 trans-11); whole milk samples were clearly differentiated from the rest using this principal component. Principal component 2 differentiated semi-skim milk samples by n-3 fatty acid content (C20:3n-3, C20:5n-3, and C22:6n-3). Principal component 3 was related to C18:2 trans-9,trans-12 and C20:4n-6, and its lower scores were observed in skim milk and non-dairy beverages. A cluster analysis yielded 3 groups: group 1 consisted of only whole milk samples, group 2 was represented mainly by semi-skim milks, and group 3 included skim milk and non-dairy beverages. Overall, the present study showed that a multivariate chemometric approach is a useful tool for differentiating or associating retail bovine milks and non-dairy beverages using their fatty acid profile.

Toward a study of gene regulatory constraints to morphological evolution of the Drosophila ocellar region.

The morphology and function of organs depend on coordinated changes in gene expression during development. These changes are controlled by transcription factors, signaling pathways, and their regulatory interactions, which are represented by gene regulatory networks (GRNs). Therefore, the structure of an organ GRN restricts the morphological and functional variations that the organ can experience-its potential morphospace. Therefore, two important questions arise when studying any GRN: what is the predicted available morphospace and what are the regulatory linkages that contribute the most to control morphological variation within this space. Here, we explore these questions by analyzing a small "three-node" GRN model that captures the Hh-driven regulatory interactions controlling a simple visual structure: the ocellar region of Drosophila. Analysis of the model predicts that random variation of model parameters results in a specific non-random distribution of morphological variants. Study of a limited sample of drosophilids and other dipterans finds a correspondence between the predicted phenotypic range and that found in nature. As an alternative to simulations, we apply Bayesian networks methods in order to identify the set of parameters with the largest contribution to morphological variation. Our results predict the potential morphological space of the ocellar complex and identify likely candidate processes to be responsible for ocellar morphological evolution using Bayesian networks. We further discuss the assumptions that the approach we have taken entails and their validity.

A Hh-driven gene network controls specification, pattern and size of the Drosophila simple eyes.

During development, extracellular signaling molecules interact with intracellular gene networks to control the specification, pattern and size of organs. One such signaling molecule is Hedgehog (Hh). Hh is known to act as a morphogen, instructing different fates depending on the distance to its source. However, how Hh, when signaling across a cell field, impacts organ-specific transcriptional networks is still poorly understood. Here, we investigate this issue during the development of the Drosophila ocellar complex. The development of this sensory structure, which is composed of three simple eyes (or ocelli) located at the vertices of a triangular patch of cuticle on the dorsal head, depends on Hh signaling and on the definition of three domains: two areas of eya and so expression--the prospective anterior and posterior ocelli--and the intervening interocellar domain. Our results highlight the role of the homeodomain transcription factor engrailed (en) both as a target and as a transcriptional repressor of hh signaling in the prospective interocellar region. Furthermore, we identify a requirement for the Notch pathway in the establishment of en maintenance in a Hh-independent manner. Therefore, hh signals transiently during the specification of the interocellar domain, with en being required here for hh signaling attenuation. Computational analysis further suggests that this network design confers robustness to signaling noise and constrains phenotypic variation. In summary, using genetics and modeling we have expanded the ocellar gene network to explain how the interaction between the Hh gradient and this gene network results in the generation of stable mutually exclusive gene expression domains. In addition, we discuss some general implications our model may have in some Hh-driven gene networks.

Stat5 signaling specifies basal versus stress erythropoietic responses through distinct binary and graded dynamic modalities.

Erythropoietin (Epo)-induced Stat5 phosphorylation (p-Stat5) is essential for both basal erythropoiesis and for its acceleration during hypoxic stress. A key challenge lies in understanding how Stat5 signaling elicits distinct functions during basal and stress erythropoiesis. Here we asked whether these distinct functions might be specified by the dynamic behavior of the Stat5 signal. We used flow cytometry to analyze Stat5 phosphorylation dynamics in primary erythropoietic tissue in vivo and in vitro, identifying two signaling modalities. In later (basophilic) erythroblasts, Epo stimulation triggers a low intensity but decisive, binary (digital) p-Stat5 signal. In early erythroblasts the binary signal is superseded by a high-intensity graded (analog) p-Stat5 response. We elucidated the biological functions of binary and graded Stat5 signaling using the EpoR-HM mice, which express a "knocked-in" EpoR mutant lacking cytoplasmic phosphotyrosines. Strikingly, EpoR-HM mice are restricted to the binary signaling mode, which rescues these mice from fatal perinatal anemia by promoting binary survival decisions in erythroblasts. However, the absence of the graded p-Stat5 response in the EpoR-HM mice prevents them from accelerating red cell production in response to stress, including a failure to upregulate the transferrin receptor, which we show is a novel stress target. We found that Stat5 protein levels decline with erythroblast differentiation, governing the transition from high-intensity graded signaling in early erythroblasts to low-intensity binary signaling in later erythroblasts. Thus, using exogenous Stat5, we converted later erythroblasts into high-intensity graded signal transducers capable of eliciting a downstream stress response. Unlike the Stat5 protein, EpoR expression in erythroblasts does not limit the Stat5 signaling response, a non-Michaelian paradigm with therapeutic implications in myeloproliferative disease. Our findings show how the binary and graded modalities combine to generate high-fidelity Stat5 signaling over the entire basal and stress Epo range. They suggest that dynamic behavior may encode information during STAT signal transduction.

Contrasting dynamic responses in vivo of the Bcl-xL and Bim erythropoietic survival pathways.

Survival signaling by the erythropoietin (Epo) receptor (EpoR) is essential for erythropoiesis and for its acceleration in hypoxic stress. Several apparently redundant EpoR survival pathways were identified in vitro, raising the possibility of their functional specialization in vivo. Here we used mouse models of acute and chronic stress, including a hypoxic environment and ß-thalassemia, to identify two markedly different response dynamics for two erythroblast survival pathways in vivo. Induction of the antiapoptotic protein Bcl-x(L) is rapid but transient, while suppression of the proapoptotic protein Bim is slower but persistent. Similar to sensory adaptation, however, the Bcl-x(L) pathway "resets," allowing it to respond afresh to acute stress superimposed on a chronic stress stimulus. Using "knock-in" mouse models expressing mutant EpoRs, we found that adaptation in the Bcl-x(L) response occurs because of adaptation of its upstream regulator Stat5, both requiring the EpoR distal cytoplasmic domain. We conclude that survival pathways show previously unsuspected functional specialization for the acute and chronic phases of the stress response. Bcl-x(L) induction provides a "stop-gap" in acute stress, until slower but permanent pathways are activated. Furthermore, pathologic elevation of Bcl-x(L) may be the result of impaired adaptation, with implications for myeloproliferative disease mechanisms.

Erythropoiesis: from molecular pathways to system properties.

Erythropoiesis is regulated through a long-range negative feedback loop, whereby tissue hypoxia stimulates erythropoietin (Epo) secretion, which promotes an increase in erythropoietic rate. However, this long-range feedback loop, by itself, cannot account for the observed system properties of erythropoiesis, namely, a wide dynamic range, stability in the face of random perturbations, and a rapid stress response. Here, we show that three Epo-regulated erythroblast survival pathways each give rise to distinct system properties. The induction of Bcl-xL by signal transducer and activator of transcription 5 (Stat5) is responsive to the rate of change in Epo levels, rather than to its absolute level, and is therefore maximally but transiently activated in acute stress. By contrast, Epo-mediated suppression of the pro-survival Fas and Bim pathways is proportional to the levels of stress/Epo and persists throughout chronic stress. Together, these elements operate in a manner reminiscent of a "proportional-integral-derivative (PID)" feedback controller frequently found in engineering applications. A short-range negative autoregulatory loop within the early erythroblast compartment, operated by Fas/FasL, filters out random noise and controls a reserve pool of early erythroblasts that is poised to accelerate the response to acute stress. Both these properties have previously been identified as inherent to negative regulatory motifs. Finally, we show that signal transduction by Stat5 combines binary and graded modalities, thereby increasing signaling fidelity over the wide dynamic range of Epo found in health and disease.

Historic Use of Race-Based Spirometry Values Lowered Transplant Priority for Black Patients.

BACKGROUND: The lung allocation score (LAS) is a tool used to prioritize patients for lung transplantation. For patients with interstitial lung diseases (ILDs), spirometry data are used for the LAS calculation. Spirometry values such as a FVC are subjected to race-specific equations that determine expected values. The effect of race-specific equations in LAS score remains unknown. RESEARCH QUESTION: Did the use of a race-based spirometry equation lead to longer waitlist times for Black patients? STUDY DESIGN AND METHODS: We performed a retrospective analysis of patients listed for lung transplantation from 2005 through 2020 using publicly available data from the United Network for Organ Sharing. We recalculated LAS scores for Black patients using White-specific equations with the available variables. The primary objective was to evaluate the effect of race-specific equations on LAS scores and time on the transplant waitlist. RESULTS: A total of 33,845 patients listed for lung transplantation were included in the analysis. White patients were listed at lower LAS scores, a higher proportion of White patients underwent transplantation, and White patients died on the waitlist at lower rates. When recalculating LAS scores using White-specific equations, Black patients with ILD had up to a 1.9-point higher score, which resulted in additional waitlist time. INTERPRETATION: Race-specific equations led to longer wait times in Black patients listed for lung transplantation. The use of race-based equations widened already known disparities in pulmonary transplantation.

Citizen attitudes towards present and future beef consumption before and after the COVID-19 pandemic.

There's been a change in citizens' attitudes towards beef consumption in high-income countries, resulting in a decline in its consumption. The COVID-19 pandemic may have impacted citizens' attitudes and behaviours towards beef consumption. This study aimed to investigate Chilean citizens' attitudes towards beef consumption during the initial 18 months of the pandemic. Socio-demographic characteristics and attitudes towards beef consumption were asked in two questionnaires done in 2020 (n = 1142) and 2021 (n = 1221). Citizens' attitudes to beef eating and production did not change between the start and more than a year after the outbreak of the COVID-19 pandemic. Participants not related with animal production, female, young, and non-meat consumers demonstrated more negative attitudes towards beef consumption and production. Half of the participants agreed that beef is bad for the environment, but only 30% agreed that beef is bad for human health. Half of participants had reduced beef consumption and 48% expressed intentions to reduce beef consumption in the future, primarily motivated by concerns related to animal welfare, the environment, and human health. The majority of participants (80%) thought that their fellow citizens should reduce their beef consumption but only 50% had confidence that this will occur. We conclude that Chilean consumers' attitudes to beef eating did not change due to the outbreak of the COVID-19 pandemic. Participants expressed strong concern about beef consumption both individually and socially, due to environmental, animal and health concerns, and believed Chileans should reduce beef consumption in the future but had low confidence that this will happen.

Antihypertensive Medications Prior to Shock Onset Do Not Impact Initial Vasopressor Requirements in Patients With Shock.

Purpose: The effect of the use of antihypertensive agents in patients prior to the development of shock is unclear. The purpose of this study was to determine the impact of antihypertensive agents on vasopressor dose and duration in shock. Materials and Methods: This retrospective, single-center study included patients with shock who received at least one vasopressor for at least 24 hours after shock onset from January 1 to June 30, 2017. Patients taking an antihypertensive agent(s) were compared to those who were not. The primary outcome was the number of vasopressor-free hours at 72 hours. Secondary outcomes included maximum and cumulative vasopressor doses, intensive care unit length of stay, and 30-day mortality. Results: One hundred and sixty-eight patients were included and 99 (59%) were on antihypertensives. Distributive shock was the most common type of shock (75.5%) and more patients taking antihypertensives had hypertension, coronary artery disease, and dyslipidemia at baseline. There was no difference in the number of vasopressor-free hours at 72 hours between patients taking an antihypertensive medication(s) and the control group (2 hours vs 1 hour; P = .11). No difference was found between any of the secondary outcomes. Conclusion: Patients taking antihypertensive agents prior to shock onset did not require increased vasopressor doses or duration.

Response of dung beetle diversity to remediation of soil ecosystems in the Ecuadorian Amazon.

Background: Efforts to alleviate the negative effects of oil spills in the Ecuadorian Amazon include remediation activities such as cleaning, reshaping, and revegetation of polluted areas. However, studies of the diversity of biological communities in these hydrocarbon-degraded ecosystems have never been carried out. Here, we evaluated the diversity of dung beetles on remediated soil ecosystems (Agricultural Soils and Sensitive Ecosystems) and on non-contaminated soils (Natural Forests and Palm Plantations). Methodology: The study was conducted in Sucumbíos and Orellana provinces, in the Ecuadorian Amazon at four sampling sites per ecosystem type (a total of 16 sites). At each sampling site, six pitfall traps remained active for 120 consecutive h per month for 1 year. Results: We collected 37 species and 7,506 individuals of dung beetles. We observed significant differences in mean species abundance, richness, and diversity between non-contaminated soil ecosystems and remediated soil ecosystems, with Natural Forests presenting the highest values, and Agricultural Soils the lowest values. Regarding sampling month, we also found significant differences among ecosystems, which were also higher in Natural Forests. Discussion: The results suggest that hydrocarbon-degraded ecosystems tend to conserve lower beetle diversity one year after remediation highlighting the importance of Natural Forests for the conservation of tropical biodiversity. Therefore, dung beetle diversity could be used for future landscape management of these hydrocarbon-degraded ecosystems.