A multi-organoid platform identifies CIART as a key factor for SARS-CoV-2 infection

Identification and targeting of regulators of SARS-CoV-2-host interactions in the airway epithelium

The impact of SARS-CoV-2 in the lung has been extensively studied, yet the molecular regulators of host-cell programs hijacked by the virus in distinct human airway epithelial cell populations remain poorly understood. Some of the reasons include overreliance on transcriptomic profiling and use of nonprimary cell systems. Here we report a network-based analysis of single-cell transcriptomic profiles able to identify master regulator (MR) proteins controlling SARS-CoV-2-mediated reprogramming in pathophysiologically relevant human ciliated, secretory, and basal cells. This underscored chromatin remodeling, endosomal sorting, ubiquitin pathways, as well as proviral factors identified by CRISPR assays as components of the viral-host response in these cells. Large-scale drug perturbation screens revealed 11 candidate drugs able to invert the entire MR signature activated by SARS-CoV-2. Leveraging MR analysis and perturbational profiles of human primary cells represents an innovative approach to investigate pathogen-host interactions in multiple airway conditions for drug prioritization.

An evolutionarily conserved constellation of functional cis-elements programs the virus-responsive fate of the human (epi)genome

Human health depends on perplexing defensive cellular responses against microbial pathogens like Viruses. Despite the major effort undertaken, the (epi)genomic mechanisms that human cells utilize to tailor defensive gene expression programs against microbial attacks have remained inadequately understood, mainly due to a significant lack of recording of the in vivo functional cis-regulatory modules (CRMs) of the human genome. Here, we introduce the virus-responsive fate of the human (epi)genome as characterized in naïve and infected cells by functional genomics, computational biology, DNA evolution, and DNA Grammar and Syntax investigations. We discovered that multitudes of novel functional virus-responsive CRMs (vrCRMs) compose typical enhancers (tEs), super-enhancers (SEs), repetitive-DNA enhancers (rDEs), and stand-alone functional genomic stretches that grant human cells regulatory underpinnings for layering basal immunity and eliminating illogical/harmful defensive responses under homeostasis, yet stimulating virus-responsive genes and transposable elements (TEs) upon infection. Moreover, extensive epigenomic reprogramming of previously unknown SE landscapes marks the transition from naïve to antiviral human cell states and involves the functions of the antimicrobial transcription factors (TFs), including interferon response factor 3 (IRF3) and nuclear factor-κB (NF-κB), as well as coactivators and transcriptional apparatus, along with intensive modifications/alterations in histone marks and chromatin accessibility. Considering the polyphyletic evolutionary fingerprints of the composite DNA sequences of the vrCRMs assessed by TFs-STARR-seq, ranging from the animal to microbial kingdoms, the conserved features of antimicrobial TFs and chromatin complexes, and their pluripotent stimulus-induced activation, these findings shed light on how mammalian (epi)genomes evolved their functions to interpret the exogenous stress inflicted and program defensive transcriptional responses against microbial agents. Crucially, many known human short variants, e.g. single-nucleotide polymorphisms (SNPs), insertions, deletions etc., and quantitative trait loci (QTLs) linked to autoimmune diseases, such as multiple sclerosis (MS), systemic lupus erythematosus (SLE), Crohn's disease (CD) etc., were mapped within or vastly proximal (±2.5 kb) to the novel in vivo functional SEs and vrCRMs discovered, thus underscoring the impact of their (mal)functions on human physiology and disease development. Hence, we delved into the virus-responsive fate of the human (epi)genome and illuminated its architecture, function, evolutionary origins, and its significance for cellular homeostasis. These results allow us to chart the "Human hyper-Atlas of virus-infection", an integrated "molecular in silico" encyclopedia situated in the UCSC Genome Browser that benefits our mechanistic understanding of human infectious/(auto)immune diseases development and can facilitate the generation of in vivo preclinical animal models, drug design, and evolution of therapeutic applications.

Organoids from pluripotent stem cells and human tissues: When two cultures meet each other

Human organoids are a widely used tool in cell biology to study homeostatic processes, disease, and development. The term organoids covers a plethora of model systems from different cellular origins that each have unique features and applications but bring their own challenges. This review discusses the basic principles underlying organoids generated from pluripotent stem cells (PSCs) as well as those derived from tissue stem cells (TSCs). We consider how well PSC- and TSC-organoids mimic the different intended organs in terms of cellular complexity, maturity, functionality, and the ongoing efforts to constitute predictive complex models of in vivo situations. We discuss the advantages and limitations associated with each system to answer different biological questions including in the field of cancer and developmental biology, and with respect to implementing emerging advanced technologies, such as (spatial) -omics analyses, CRISPR screens, and high-content imaging screens. We postulate how the two fields may move forward together, integrating advantages of one to the other.

SCovid v2.0: a comprehensive resource to decipher the molecular characteristics across tissues in COVID-19 and other human coronaviruses

SCovid v2.0 (http://bio-annotation.cn/scovid or http://bio-computing.hrbmu.edu.cn/scovid/) is an updated database designed to assist researchers in uncovering the molecular characteristics of coronavirus disease 2019 (COVID-19) across various tissues through transcriptome sequencing. Compared with its predecessor, SCovid v2.0 is enhanced with comprehensive data, practical functionalities, and a reconstructed pipeline. The current release includes (i) 3,544,360 cells from 45 single-cell RNA-seq (scRNA-seq) data sets encompassing 789 samples from 15 tissues; (ii) the addition of 62 COVID-19 bulk RNA-seq data comprising 1,688 samples from 12 tissues; (iii) incorporation of seven bulk RNA-seq data sets related to other human coronaviruses, such as HCoV-229E, HCoV-OC43, and MERS-CoV for a thorough comparative analysis of pan-coronavirus mechanisms in COVID-19; and (iv) systematic comparisons between the data sets conducted using standardized procedures. Furthermore, we have developed an advanced search engine and upgraded web interface to browse, search, visualize, and download detailed information. Overall, SCovid v2.0 is a valuable resource for exploring molecular characteristics of COVID-19 across different tissues.

IMPORTANCE

This manuscript provides a comprehensive analysis of the molecular characteristics of COVID-19 through cross-tissue transcriptome analysis, contributing to the understanding of COVID-19 by clinicians and scientists. Considering the cyclical nature of coronavirus outbreaks, this updated database adds transcriptome data on other human coronaviruses, contributing to potential and existing mechanisms of other human coronaviruses.

Hypoosmotic stress shifts transcription of circadian genes

Cells respond to hypoosmotic stress by initial swelling followed by intracellular increases in the number of osmolytes and initiation of gene transcription that allow cells to adapt to the stress. Here, we have studied the genes that change expression under mild hypoosmotic stress for 12 and 24 h in rat cultured smooth muscle cells (WKO-3M22). We find shifts in the transcription of many genes, several of which are associated with circadian rhythm, such as per1, nr1d1, per2, dbp, and Ciart. To determine whether there is a connection between osmotic stress and circadian rhythm, we first subjected cells to hypoosmotic stress for 12 h, and find that Bmal1, a transcription factor whose nuclear localization promotes transit through the cell cycle, localizes to the cytoplasm, which may connect osmotic stress to cell cycle. Bmal1 nuclear localization recovers after 24 h and cell cycle resumes even though the osmotic stress remains elevated. We hypothesized that osmotic force is transmitted into the cell by deforming caveolae membrane domains releasing one of its structural proteins, cavin-1, which can travel to the nucleus and affect gene transcription. In support of this idea, we find that Bmal1 localization becomes independent of osmotic stress with cavin-1 downregulation, and Bmal1 localization is independent of osmotic stress in a cell line with low caveolae expression. These studies indicate that osmotic stress transiently arrests circadian rhythm and cell-cycle progression through caveolae deformation.

Organoids and microphysiological systems for pharmaceutical research of viral respiratory infections

In the pharmaceutical research of viral respiratory infections, cell culture models have traditionally been used to evaluate the therapeutic effects of candidate compounds. Although cell lines are easy to handle and cost-effective, they do not fully replicate the characteristics of human respiratory organs. Recently, organoids and microphysiological systems (MPS) have been employed to overcome this limitation for in vitro testing of drugs against viral respiratory infections. Advanced disease modeling using organoids, self-organized three-dimensional (3D) cell culture models derived from stem cells, or MPS, models for culturing multiple cell types in a microfluidic device and capable of recapitulating a physiological 3D dynamic environment, can accurately replicate the complex functions of respiratory organs, thus making them valuable tools for elucidating the organ damages caused by viral respiratory infections and evaluating the efficacy of candidate drugs against them. Recently, a wide range of organoids and MPS have been developed to model the complex pathophysiology caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and assess therapeutic drugs. In this review, we evaluate the latest pharmaceutical research on coronavirus disease 2019 (COVID-19) that utilizes organoids and MPS and discuss future perspectives of their applications.

Identification and Targeting of Regulators of SARS-CoV-2-Host Interactions in the Airway Epithelium

Although the impact of SARS-CoV-2 in the lung has been extensively studied, the molecular regulators and targets of the host-cell programs hijacked by the virus in distinct human airway epithelial cell populations remain poorly understood. This is in part ascribed to the use of nonprimary cell systems, overreliance on single-cell gene expression profiling that does not ultimately reflect protein activity, and bias toward the downstream effects rather than their mechanistic determinants. Here we address these issues by network-based analysis of single cell transcriptomic profiles of pathophysiologically relevant human adult basal, ciliated and secretory cells to identify master regulator (MR) protein modules controlling their SARS-CoV-2-mediated reprogramming. This uncovered chromatin remodeling, endosomal sorting, ubiquitin pathways, as well as proviral factors identified by CRISPR analyses as components of the host response collectively or selectively activated in these cells. Large-scale perturbation assays, using a clinically relevant drug library, identified 11 drugs able to invert the entire MR signature activated by SARS-CoV-2 in these cell types. Leveraging MR analysis and perturbational profiles of human primary cells represents a novel mechanism-based approach and resource that can be directly generalized to interrogate signatures of other airway conditions for drug prioritization.

The nuclear transportation of CHRONO regulates the circadian rhythm

The pace of the endogenous circadian clock is important for organisms to maintain homeostasis. CHRONO has been shown to be a core component of the mammalian clock and has recently been implicated to function in several important physiological aspects. To function properly, CHRONO needs to enter the nucleus to repress transcription. We have previously shown that the N terminus of CHRONO is required for its nuclear entry. However, how CHRONO enters the nucleus and regulates the circadian clock remains unknown. Here, we report that a novel nonclassical nuclear localization signal in the N terminus of CHRONO is responsible for its nuclear entry. Multiple nuclear transporters are identified that facilitate the nuclear import of CHRONO. We show that the Arg63 is the critical amino acid of the nuclear localization signal. Using prime editing technology, we precisely edit the Arg63 to Ala at the genomic loci and demonstrate that this mutation prolongs the circadian period, which is similar to knockdown of CHRONO. By using the CHRONO KO and R63A mutant cells, we also investigated the changes in the cytoplasmic/nuclear distribution of BMAL1. We show that BMAL1 localizes more in the cytoplasm in the deficiency of CHRONO nuclear entry. These results provide a model for CHRONO nuclear entry using a network of importins involved in the regulation of the circadian period.

Advancing zoonotic respiratory virus research through the use of organoids

Zoonotic viruses with the ability to replicate in the human respiratory tract pose a threat to public health. Organoids, which are highly representative, multicellular models representing specific organs or tissues, can aid in our understanding of the pathogenesis, pathogenicity, transmissibility, and reservoir circulation dynamics of zoonotic viruses. Organoid studies can facilitate the rapid selection of antiviral therapies identification of potential reservoir species and intermediate hosts, and inform the selection of suitable laboratory animal models. We review the use of human- and animal-derived organoid models from multiple organs to investigate the threat of emerging zoonotic viruses that cause respiratory disease.

Next-generation treatments: Immunotherapy and advanced therapies for COVID-19

The COVID-19 pandemic, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), emerged in 2019 following prior outbreaks of coronaviruses like SARS and MERS in recent decades, underscoring their high potential of infectivity in humans. Insights from previous outbreaks of SARS and MERS have played a significant role in developing effective strategies to mitigate the global impact of SARS-CoV-2. As of January 7, 2024, there have been 774,075,242 confirmed cases of COVID-19 worldwide. To date, 13.59 billion vaccine doses have been administered, and there have been 7,012,986 documented fatalities (https://www.who.int/) Despite significant progress in addressing the COVID-19 pandemic, the rapid evolution of SARS-CoV-2 challenges human defenses, presenting ongoing global challenges. The emergence of new SARS-CoV-2 lineages, shaped by mutation and recombination processes, has led to successive waves of infections. This scenario reveals the need for next-generation vaccines as a crucial requirement for ensuring ongoing protection against SARS-CoV-2. This demand calls for formulations that trigger a robust adaptive immune response without leading the acute inflammation linked with the infection. Key mutations detected in the Spike protein, a critical target for neutralizing antibodies and vaccine design -specifically within the Receptor Binding Domain region of Omicron variant lineages (B.1.1.529), currently dominant worldwide, have intensified concerns due to their association with immunity evasion from prior vaccinations and infections. As the world deals with this evolving threat, the narrative extends to the realm of emerging variants, each displaying new mutations with implications that remain largely misunderstood. Notably, the JN.1 Omicron lineage is gaining global prevalence, and early findings suggest it stands among the immune-evading variants, a characteristic attributed to its mutation L455S. Moreover, the detrimental consequences of the novel emergence of SARS-CoV-2 lineages bear a particularly critical impact on immunocompromised individuals and older adults. Immunocompromised individuals face challenges such as suboptimal responses to COVID-19 vaccines, rendering them more susceptible to severe disease. Similarly, older adults have an increased risk of severe disease and the presence of comorbid conditions, find themselves at a heightened vulnerability to develop COVID-19 disease. Thus, recognizing these intricate factors is crucial for effectively tailoring public health strategies to protect these vulnerable populations. In this context, this review aims to describe, analyze, and discuss the current progress of the next-generation treatments encompassing immunotherapeutic approaches and advanced therapies emerging as complements that will offer solutions to counter the disadvantages of the existing options. Preliminary outcomes show that these strategies target the virus and address the immunomodulatory responses associated with COVID-19. Furthermore, the capacity to promote tissue repair has been demonstrated, which can be particularly noteworthy for immunocompromised individuals who stand as vulnerable actors in the global landscape of coronavirus infections. The emerging next-generation treatments possess broader potential, offering protection against a wide range of variants and enhancing the ability to counter the impact of the constant evolution of the virus. Furthermore, advanced therapies are projected as potential treatment alternatives for managing Chronic Post-COVID-19 syndromeand addressing its associated long-term complications.

Swimming exercise reverses transcriptomic changes in aging mouse lens

BACKGROUND

The benefits of physical activity for the overall well-being of elderly individuals are well-established, the precise mechanisms through which exercise improves pathological changes in the aging lens have yet to be fully understood.

METHODS

3-month-old C57BL/6J mice comprised young sedentary (YS) group, while aging mice (18-month-old) were divided into aging sedentary (AS) group and aging exercising (AE) group. Mice in AE groups underwent sequential stages of swimming exercise. H&E staining was employed to observe alterations in lens morphology. RNA-seq analysis was utilized to examine transcriptomic changes. Furthermore, qPCR and immunohistochemistry were employed for validation of the results.

RESULTS

AE group showed alleviation of histopathological aging changes in AS group. By GSEA analysis of the transcriptomic changes, swimming exercise significantly downregulated approximately half of the pathways that underwent alterations upon aging, where notable improvements were 'calcium signaling pathway', 'neuroactive ligand receptor interaction' and 'cell adhesion molecules'. Furthermore, we revealed a total of 92 differentially expressed genes between the YS and AS groups, of which 10 genes were observed to be mitigated by swimming exercise. The result of qPCR was in consistent with the transcriptome data. We conducted immunohistochemical analysis on Ciart, which was of particular interest due to its dual association as a common aging gene and its significant responsiveness to exercise. The Protein-protein Interaction network of Ciart showed the involvement of the regulation of Rorb and Sptbn5 during the process.

CONCLUSION

The known benefits of exercise could extend to the aging lens and support further investigation into the specific roles of Ciart-related pathways in aging lens.

Advanced lung organoids for respiratory system and pulmonary disease modeling

Amidst the recent coronavirus disease 2019 (COVID-19) pandemic, respiratory system research has made remarkable progress, particularly focusing on infectious diseases. Lung organoid, a miniaturized structure recapitulating lung tissue, has gained global attention because of its advantages over other conventional models such as two-dimensional (2D) cell models and animal models. Nevertheless, lung organoids still face limitations concerning heterogeneity, complexity, and maturity compared to the native lung tissue. To address these limitations, researchers have employed co-culture methods with various cell types including endothelial cells, mesenchymal cells, and immune cells, and incorporated bioengineering platforms such as air-liquid interfaces, microfluidic chips, and functional hydrogels. These advancements have facilitated applications of lung organoids to studies of pulmonary diseases, providing insights into disease mechanisms and potential treatments. This review introduces recent progress in the production methods of lung organoids, strategies for improving maturity, functionality, and complexity of organoids, and their application in disease modeling, including respiratory infection and pulmonary fibrosis.

Lipid compartments and lipid metabolism as therapeutic targets against coronavirus

Lipids perform a series of cellular functions, establishing cell and organelles' boundaries, organizing signaling platforms, and creating compartments where specific reactions occur. Moreover, lipids store energy and act as secondary messengers whose distribution is tightly regulated. Disruption of lipid metabolism is associated with many diseases, including those caused by viruses. In this scenario, lipids can favor virus replication and are not solely used as pathogens' energy source. In contrast, cells can counteract viruses using lipids as weapons. In this review, we discuss the available data on how coronaviruses profit from cellular lipid compartments and why targeting lipid metabolism may be a powerful strategy to fight these cellular parasites. We also provide a formidable collection of data on the pharmacological approaches targeting lipid metabolism to impair and treat coronavirus infection.

Functional interrogation of twenty type 2 diabetes-associated genes using isogenic human embryonic stem cell-derived β-like cells

Genetic studies have identified numerous loci associated with type 2 diabetes (T2D), but the functional roles of many loci remain unexplored. Here, we engineered isogenic knockout human embryonic stem cell lines for 20 genes associated with T2D risk. We examined the impacts of each knockout on β cell differentiation, functions, and survival. We generated gene expression and chromatin accessibility profiles on β cells derived from each knockout line. Analyses of T2D-association signals overlapping HNF4A-dependent ATAC peaks identified a likely causal variant at the FAIM2 T2D-association signal. Additionally, the integrative association analyses identified four genes (CP, RNASE1, PCSK1N, and GSTA2) associated with insulin production, and two genes (TAGLN3 and DHRS2) associated with β cell sensitivity to lipotoxicity. Finally, we leveraged deep ATAC-seq read coverage to assess allele-specific imbalance at variants heterozygous in the parental line and identified a single likely functional variant at each of 23 T2D-association signals.

Uncoupled redox stress: how a temporal misalignment of redox-regulated processes and circadian rhythmicity exacerbates the stressed state

Diurnal and seasonal rhythmicity, entrained by environmental and nutritional cues, is a vital part of all life on Earth operating at every level of organization; from individual cells, to multicellular organisms, whole ecosystems and societies. Redox processes are intrinsic to physiological function and circadian regulation, but how they are integrated with other regulatory processes at the whole-body level is poorly understood. Circadian misalignment triggered by a major stressor (e.g. viral infection with SARS-CoV-2) or recurring stressors of lesser magnitude such as shift work elicit a complex stress response that leads to desynchronization of metabolic processes. This in turn challenges the system's ability to achieve redox balance due to alterations in metabolic fluxes (redox rewiring). We infer that the emerging 'alternative redox states' do not always revert readily to their evolved natural states; 'Long COVID' and other complex disorders of unknown aetiology are the clinical manifestations of such rearrangements. To better support and successfully manage bodily resilience to major stress and other redox challenges needs a clear perspective on the pattern of the hysteretic response for the interaction between the redox system and the circadian clock. Characterization of this system requires repeated (ideally continuous) recording of relevant clinical measures of the stress responses and whole-body redox state (temporal redox phenotyping). The human/animal body is a complex 'system of systems' with multi-level buffering capabilities, and it requires consideration of the wider dynamic context to identify a limited number of stress-markers suitable for routine clinical decision making. Systematically mapping the patterns and dynamics of redox biomarkers along the stressor/disease trajectory will provide an operational model of whole-body redox regulation/balance that can serve as basis for the identification of effective interventions which promote health by enhancing resilience.

Functional interrogation of twenty type 2 diabetes-associated genes using isogenic hESC-derived β-like cells

Genetic studies have identified numerous loci associated with type 2 diabetes (T2D), but the functional role of many loci has remained unexplored. In this study, we engineered isogenic knockout human embryonic stem cell (hESC) lines for 20 genes associated with T2D risk. We systematically examined β-cell differentiation, insulin production and secretion, and survival. We performed RNA-seq and ATAC-seq on hESC-β cells from each knockout line. Analyses of T2D GWAS signals overlapping with HNF4A-dependent ATAC peaks identified a specific SNP as a likely causal variant. In addition, we performed integrative association analyses and identified four genes ( CP, RNASE1, PCSK1N and GSTA2 ) associated with insulin production, and two genes ( TAGLN3 and DHRS2 ) associated with sensitivity to lipotoxicity. Finally, we leveraged deep ATAC-seq read coverage to assess allele-specific imbalance at variants heterozygous in the parental hESC line, to identify a single likely functional variant at each of 23 T2D GWAS signals.