At the beginning of June 2020, there were nearly 7 million reported cases of coronavirus disease 2019 (COVID-19) worldwide and over 400,000 deaths in people with COVID-19. The objective of this study ...was to determine associations between comorbidities listed in the Charlson comorbidity index and mortality among patients in the United States with COVID-19.
A retrospective cohort study of adults with COVID-19 from 24 healthcare organizations in the US was conducted. The study included adults aged 18-90 years with COVID-19 coded in their electronic medical records between January 20, 2020, and May 26, 2020. Results were also stratified by age groups (<50 years, 50-69 years, or 70-90 years). A total of 31,461 patients were included. Median age was 50 years (interquartile range IQR, 35-63) and 54.5% (n = 17,155) were female. The most common comorbidities listed in the Charlson comorbidity index were chronic pulmonary disease (17.5%, n = 5,513) and diabetes mellitus (15.0%, n = 4,710). Multivariate logistic regression analyses showed older age (odds ratio OR per year 1.06; 95% confidence interval CI 1.06-1.07; p < 0.001), male sex (OR 1.75; 95% CI 1.55-1.98; p < 0.001), being black or African American compared to white (OR 1.50; 95% CI 1.31-1.71; p < 0.001), myocardial infarction (OR 1.97; 95% CI 1.64-2.35; p < 0.001), congestive heart failure (OR 1.42; 95% CI 1.21-1.67; p < 0.001), dementia (OR 1.29; 95% CI 1.07-1.56; p = 0.008), chronic pulmonary disease (OR 1.24; 95% CI 1.08-1.43; p = 0.003), mild liver disease (OR 1.26; 95% CI 1.00-1.59; p = 0.046), moderate/severe liver disease (OR 2.62; 95% CI 1.53-4.47; p < 0.001), renal disease (OR 2.13; 95% CI 1.84-2.46; p < 0.001), and metastatic solid tumor (OR 1.70; 95% CI 1.19-2.43; p = 0.004) were associated with higher odds of mortality with COVID-19. Older age, male sex, and being black or African American (compared to being white) remained significantly associated with higher odds of death in age-stratified analyses. There were differences in which comorbidities were significantly associated with mortality between age groups. Limitations include that the data were collected from the healthcare organization electronic medical record databases and some comorbidities may be underreported and ethnicity was unknown for 24% of participants. Deaths during an inpatient or outpatient visit at the participating healthcare organizations were recorded; however, deaths occurring outside of the hospital setting are not well captured.
Identifying patient characteristics and conditions associated with mortality with COVID-19 is important for hypothesis generating for clinical trials and to develop targeted intervention strategies.
Cell and tissue engineering for liver disease Bhatia, Sangeeta N; Underhill, Gregory H; Zaret, Kenneth S ...
Science translational medicine,
07/2014, Letnik:
6, Številka:
245
Journal Article
Recenzirano
Odprti dostop
Despite the tremendous hurdles presented by the complexity of the liver's structure and function, advances in liver physiology, stem cell biology and reprogramming, and the engineering of tissues and ...devices are accelerating the development of cell-based therapies for treating liver disease and liver failure. This State of the Art Review discusses both the near- and long-term prospects for such cell-based therapies and the unique challenges for clinical translation.
Abstract Recent approaches have utilized microfabricated platforms to examine combinations of microenvironmental signals that regulate stem and progenitor cell differentiation. However, the majority ...of these efforts have focused on the biochemical properties of extracellular matrix (ECM) or soluble factors without simultaneously exploring the biomechanical effects of cell–substrate interactions. To address this need, we combined a high-throughput approach for the analysis of combinatorial ECM cues with substrates of modular stiffness and traction force microscopy. This integrated approach enabled the characterization of cell-generated traction stress and phenotypic expression in response to ECM cues. We investigated the impact of substrate stiffness and ECM composition on the differentiation of bipotential mouse embryonic liver (BMEL) progenitor cells. We observed that hepatocyte differentiation was primarily regulated by ECM composition, and cholangiocyte differentiation was cooperatively influenced by ECM proteins and stiffness properties. In particular, stiffness-mediated cholangiocyte differentiation was observed for cells cultured on fibronectin, while collagen IV promoted differentiation independent of substrate stiffness. We demonstrated the influence of cell contractility and traction stress in early cholangiocyte specification and further uncovered the roles of ERK and ROCK in this differentiation process. Overall, these findings illustrate the involvement of biomechanical signals in liver progenitor differentiation. Further, this approach could enable investigations for a broad range of cell types and ECM proteins, providing an integrated platform for evaluating the combinatorial effects of biochemical and biophysical signals in cell differentiation.
In vitro models of the human liver are important for the following: (1) mitigating the risk of drug-induced liver injury to human beings, (2) modeling human liver diseases, (3) elucidating the role ...of single and combinatorial microenvironmental cues on liver cell function, and (4) enabling cell-based therapies in the clinic. Methods to isolate and culture primary human hepatocytes (PHHs), the gold standard for building human liver models, were developed several decades ago; however, PHHs show a precipitous decline in phenotypic functions in 2-dimensional extracellular matrix–coated conventional culture formats, which does not allow chronic treatment with drugs and other stimuli. The development of several engineering tools, such as cellular microarrays, protein micropatterning, microfluidics, biomaterial scaffolds, and bioprinting, now allow precise control over the cellular microenvironment for enhancing the function of both PHHs and induced pluripotent stem cell–derived human hepatocyte-like cells; long-term (4+ weeks) stabilization of hepatocellular function typically requires co-cultivation with liver-derived or non–liver-derived nonparenchymal cell types. In addition, the recent development of liver organoid culture systems can provide a strategy for the enhanced expansion of therapeutically relevant cell types. Here, we discuss advances in engineering approaches for constructing in vitro human liver models that have utility in drug screening and for determining microenvironmental determinants of liver cell differentiation/function. Design features and validation data of representative models are presented to highlight major trends followed by the discussion of pending issues that need to be addressed. Overall, bioengineered liver models have significantly advanced our understanding of liver function and injury, which will prove useful for drug development and ultimately cell-based therapies.
Metabolism in the liver often determines the overall clearance rates of many pharmaceuticals. Furthermore, induction or inhibition of the liver drug metabolism enzymes by perpetrator drugs can ...influence the metabolism of victim drugs (drug-drug interactions). Therefore, determining liver-drug interactions is critical during preclinical drug development. Unfortunately, studies in animals are often of limited value because of significant differences in the metabolic pathways of the liver across different species. To mitigate such limitations, the pharmaceutical industry uses a continuum of human liver models, ranging from microsomes to transfected cell lines and cultures of primary human hepatocytes (PHHs). Of these models, PHHs provide a balance of high-throughput testing capabilities together with a physiologically relevant cell type that exhibits all the characteristic enzymes, cofactors, and transporters. However, PHH monocultures display a rapid decline in metabolic capacity. Consequently, bioengineers have developed several tools, such as cellular microarrays, micropatterned cocultures, self-assembled and bioprinted spheroids, and perfusion devices, to enhance and stabilize PHH functions for ≥2 weeks. Many of these platforms have been validated for drug studies, whereas some have been adapted to include liver nonparenchymal cells that can influence hepatic drug metabolism in health and disease. Here, we focus on the design features of such platforms and their representative drug metabolism validation datasets, while discussing emerging trends. Overall, the use of engineered human liver platforms in the pharmaceutical industry has been steadily rising over the last 10 years, and we anticipate that these platforms will become an integral part of drug development with continued commercialization and validation for routine screening use.
Hepatic stellate cells (HSCs) are one of the primary drivers of liver fibrosis in non-alcoholic fatty liver disease. Although HSC activation in liver disease is associated with changes in ...extracellular matrix (ECM) deposition and remodeling, it remains unclear how ECM regulates the phenotypic state transitions of HSCs. Using high-throughput cellular microarrays, coupled with genome-wide ATAC and RNA sequencing within engineered ECM microenvironments, we investigated the effect of ECM and substrate stiffness on chromatin accessibility and resulting gene expression in activated primary human HSCs. Cell microarrays demonstrated the cooperative effects of stiffness and ECM composition on H3K4 and H3K9 methylation/acetylation. ATAC sequencing revealed higher chromatin accessibility in HSCs on 1kPa compared to 25kPa substrates for all ECM conditions. Gene set enrichment analysis using RNA sequencing data of HSCs in defined ECM microenvironments demonstrated higher enrichment of NAFLD and fibrosis-related genes in pre-activated HSCs on 1kPa relative to 25kPa. Overall, these findings are indicative of a microenvironmental adaptation response in HSCs, and the acquisition of a persistent activation state. Combined ATAC/RNA sequencing analyses enabled identification of candidate regulatory factors, including HSD11B1 and CEBPb. siRNA-mediated knockdown of HSD11b1 and CEBPb demonstrated microenvironmental controlled reduction in fibrogenic markers in HSCs.
Hepatic stellate cells (HSCs) are one of the primary drivers of liver fibrosis in non-alcoholic fatty liver disease. Although HSC activation in liver disease is associated with changes in extracellular matrix (ECM) deposition and remodeling, it remains unclear how ECM regulates the phenotypic state transitions of HSCs. Using high-throughput cellular microarrays, coupled with genome-wide ATAC and RNA sequencing within engineered ECM microenvironments, we investigated the effect of ECM and substrate stiffness on chromatin accessibility and resulting gene expression in activated primary human HSCs. Overall, these findings were indicative of a microenvironmental adaptation response in HSCs, and the acquisition of a persistent activation state. Combined ATAC/RNA sequencing analyses enabled identification of candidate regulatory factors, including HSD11B1 and CEBPb. siRNA-mediated knockdown of HSD11b1 and CEBPb demonstrated microenvironmental controlled reduction in fibrogenic markers in HSCs.
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Successful application of living cells in regenerative medicine requires an understanding of how tissue structure relates to organ function. There is growing evidence that presentation of ...extracellular cues in a three-dimensional (3D) context can fundamentally alter cellular responses. Thus, microenvironment studies that previously were limited to adherent two-dimensional (2D) cultures may not be appropriate for many cell types. Here we present a method for the rapid formation of reproducible, high-resolution 3D cellular structures within a photopolymerizable hydrogel using dielectrophoretic forces. We demonstrate the parallel formation of >20,000 cell clusters of precise size and shape within a thin 2-cm(2) hydrogel and the maintenance of high cell viability and differentiated cell markers over 2 weeks. By modulating cell-cell interactions in 3D clusters, we present the first evidence that microscale tissue organization regulates bovine articular chondrocyte biosynthesis. This platform permits investigation of tissue architecture in other multicellular processes, from embryogenesis to regeneration to tumorigenesis.
Intercellular communication through secreted proteins is necessary in essential processes such as embryo and limb development, disease progression, and immune responses. There exist many techniques ...to study bulk solution protein concentrations, but there is a limited set of tools to study the concentrations of cell-secreted proteins in situ within diverse cell platforms while retaining spatial information. In this study, we have developed a microgel system that is able to quantitatively measure the cell-secreted protein concentration within defined three-dimensional culture configurations with single-cell spatial resolution, called μGeLISA (microgel-linked immunosorbent assay). This system, which is based on the surface modification of polyethylene glycol microgels, was able to detect interleukin 6 (IL-6) concentrations of 2.21–21.86 ng/mL. Microgels were also able to detect cell spheroid-secreted IL-6 and distinguish between low- and high-secreting single cells. The system was also adapted to measure the concentration of cell-secreted matrix metalloproteinase-2 (MMP-2). μGeLISA represents a highly versatile system with a straightforward fabrication process that can be adapted toward the detection of secreted proteins within a diverse range of cell culture configurations.
Background
COVID‐19 has a wide spectrum of cardiovascular sequelae including myocarditis and pericarditis; however, the prevalence and clinical impact are unclear. We investigated the prevalence of ...new‐onset myocarditis/pericarditis and associated adverse cardiovascular events in patients with COVID‐19.
Methods and results
A retrospective cohort study was conducted using electronic medical records from a global federated health research network. Patients were included based on a diagnosis of COVID‐19 and new‐onset myocarditis or pericarditis. Patients with COVID‐19 and myocarditis/pericarditis were 1:1 propensity score matched for age, sex, race and comorbidities to patients with COVID‐19 but without myocarditis/pericarditis. The outcomes of interest were 6‐month all‐cause mortality, hospitalisation, cardiac arrest, incident heart failure, incident atrial fibrillation and acute myocardial infarction, comparing patients with and without myocarditis/pericarditis.
Of 718,365 patients with COVID‐19, 35,820 (5.0%) developed new‐onset myocarditis and 10,706 (1.5%) developed new‐onset pericarditis. Six‐month all‐cause mortality was 3.9% (n = 702) in patients with myocarditis and 2.9% (n = 523) in matched controls (p < .0001), odds ratio 1.36 (95% confidence interval (CI): 1.21–1.53). Six‐month all‐cause mortality was 15.5% (n = 816) for pericarditis and 6.7% (n = 356) in matched controls (p < .0001), odds ratio 2.55 (95% CI: 2.24–2.91). Receiving critical care was associated with significantly higher odds of mortality for patients with myocarditis and pericarditis. Patients with pericarditis seemed to associate with more new‐onset cardiovascular sequelae than those with myocarditis. This finding was consistent when looking at pre‐COVID‐19 data with pneumonia patients.
Conclusions
Patients with COVID‐19 who present with myocarditis/pericarditis associate with increased odds of major adverse events and new‐onset cardiovascular sequelae.
Liver sinusoidal endothelial cells (LSECs) differ, both structurally and functionally, from endothelial cells (ECs) lining blood vessels of other tissues. For example, in contrast to other ECs, LSECs ...possess fenestrations, have low detectable levels of platelet endothelial cell adhesion molecule 1 expression, and in rat tissue, they distinctively express a cell surface marker recognized by the SE‐1 antibody. These unique phenotypic characteristics seen in hepatic tissue are lost over time upon culture in vitro; therefore, this study sought to systematically examine the effects of microenvironmental stimuli—namely, extracellular matrix and neighboring cells, on the LSEC phenotype in vitro. In probing the role of the underlying extracellular matrix, we identified collagen I and collagen III as well as mixtures of collagen I/collagen IV/fibronectin as having a positive effect on LSEC survival. Furthermore, using a stable hepatocellular model (hepatocyte–fibroblast) we were able to prolong the expression of both SE‐1 and phenotypic functions of LSEC such as factor VIII activity and AcLOL uptake in cocultured LSECs through the production of short‐range paracrine signals. In the course of these experiments, we identified the antigen recognized by SE‐1 as CD32b. Conclusion: Collectively, this study has identified several microenvironmental regulators of liver sinusoidal endothelial cells that prolong their phenotypic functions for up to 2 weeks in culture, enabling the development of better in vitro models of liver physiology and disease. (HEPATOLOGY 2009.)
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