Pathobiological Mechanisms Research Articles

Equitable endotyping is essential to achieve a global standard of precise, effective, and locally-relevant sepsis care.

Over the past two decades, elucidation of the host response to severe infection has uncovered the complex and dynamic derangements in immune, endothelial, and metabolic homeostasis that underlie sepsis pathobiology.1,2 Leveraging advances in high-dimensional host response profiling and computational methods (e.g., machine learning, structural equation modelling), identification of patient subgroups defined by distinct clinico-molecular features (“subphenotypes”) and pathobiological mechanisms (“endotypes”) represents a promising approach to achieve biological deconvolution of the heterogenous sepsis phenotype.

Molecular Patterns Identify Distinct Subclasses of Myeloid Neoplasia

The diverse molecular pathogenesis of MDS underpins its pathomorphologic and clinical heterogeneity, ultimately converging in a stepwise progression to leukemia. The identification of hallmarks morphological features, hampered by inter-observer variability, limited a precise resolution of pathogenic differences, partially mitigated by the inclusion of cytogenetic abnormalities, the two pillars of MDS classification. The advent of NGS led to the discovery of a multitude of mutations, and their combinations unveiled a tremendous molecular diversity in MDS. Intuitively, molecular patterning has been used in supervised fashion to fit morphologic classification, but this approach ensured only a limited success. Machine learning (ML) analytic methods, as demonstrated in acute myeloid leukemia (AML), provide new opportunities to integrate molecular data and identify functionally convergent patterns manifesting with similar clinical outcomes. Particularly, ML approaches can identify cryptic molecular interactions and pathogenic mechanisms irrespective of their often comparable impact on outcomes. Here, we took advantage of a large, well-annotated multicenter cohort of MDS and secondary AML (sAML) cases (N=3588) to test the hypothesis that related molecular patterns can be analyzed in an unbiased/unsupervised fashion to characterize molecularly-defined configurations. Our aim was not meant to compete with or replace current prognostication tools (including the new molecular prognostic score)2 but rather to illuminate the genetic sub-classification of MDS and related conditions in an operator-independent fashion, according to molecular correlations and mutual functional proximity, irrespective of their impact on clinical outcomes. Molecular signatures driving each cluster were identified and used for genomic subclassification that separated functionally related subtypes in an outcome independent fashion. We then validated the model on 412 patients from two external institutions. Among the 3588 patients included in this cohort, 735 (20%) had sAML, 774 (22%) had higher-risk MDS (HR-MDS), and 2079 (58%) had lower-risk MDS (LR-MDS). Abnormal karyotype was found in 43% of the cases, and 77% had at least one somatic mutation, with 8% harboring >4 mutations. ML analysis identified 14 distinctive molecular clusters (MCs) with unique pathobiological associations, treatment responses, and prognosis (Fig.1A). Normal karyotype (NK) was enriched in MC2, MC4, MC6, MC9, MC10, and MC12 with different distributions of ASXL1, DNMT3A,JAK2, RAS, SF3B1, and TET2 mutations. Complex karyotype and trisomy 8 were enriched in MC13 and MC1, respectively. Remarkably, our ML approach identified functionally relevant genomic clusters (Fig.1A). For instance, MC2, MC6, and MC8 demonstrated distinct genomic signatures: MC2 included cases with NK only (100%) and some DNMT3A (11%), JAK2 (11%), and RAS pathway (10%) mutations; MC6 cases had similar features to MC2 but were also enriched in SRSF2 (49%) and RAS mutations (23%); MC8 was instead characterized by the presence of del5q/-5 (100%), DNMT3A (17%), and TP53 (17%) mutations. MC13 contained cases with complex karyotype (100%) and TP53 (44%) mutations (Fig1.B). We then identified five risk groups to reflect the biological differences between clusters. Our clustering model highlighted the significant survival differences among patients assigned within similar IPSS-R risk groups but displaying heterogeneous molecular configurations. Different response rates to hypomethylating agents (e.g., MC9 and MC13 [OR: 2.2 and 0.6, respectively]) paralleled the biological differences across the clusters. Interestingly, our MCs retained significant survival differences regardless of the bone marrow blast percentage. Our model is available via web-based access resource (https://drmz.shinyapps.io/mds_latent). Despite the complexity and the diversity of molecular alterations in MDS/sAML, by deploying ML we were able to identify and distinguish functional and pathologically related MCs irrespective of the anamnestic clinico-morphological features. In recognition that similar outcomes do not warrant similar molecular features, our model provides genomic signatures for a better understanding of the pathobiological mechanisms of disease, progression to higher stages, and identification of future therapeutic vulnerabilities. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Abstract 14950: Single-Cell Transcriptomic Analysis Reveals Emergence of Inflammatory and Activated Arterial Endothelial Cells Promoted by Cross-Talk With Mural Cells During Development of Severe Pulmonary Arterial Hypertension

Introduction: Pulmonary arterial hypertension (PAH) is a lethal disease characterized by occlusive arterial remodelling thought to be triggered by endothelial cell (EC) injury; however, the pathobiological mechanisms are poorly understood. We employed single cell RNA sequencing (scRNAseq) to define transcriptomic changes in the SU5416/chronic hypoxia (SU/CH) rat model. Methods: Sprague-Dawley rats were injected with 20mg/kg SU subcutaneously and exposed to 3 weeks of CH (10% O 2 ). Right ventricular systolic pressure (RVSP) was measured at baseline, 1, 3, 5, and 8-weeks, then lungs were explanted, digested, and dissociated into single cells which were sequenced using the 10x genomics platform. Results: Elevation of RVSP plateaued at >100 mmHg by 5 weeks. Dimensionality reduction of the scRNAseq data was performed using Uniform Manifold Approximation and Projection (UMAP) analysis resulting in 24 lung clusters. Cell prioritization analysis performed using Augur identified vascular cells as the most affected by SU/CH, including arterial ECs, pericytes, and gCap ECs. After sub-clustering the EC populations, eight distinct clusters were identified representing all expected subtypes (capillary, arterial, venous, and lymphatic). As well, two novel EC clusters were detected. The first showed reduced expression of classical EC genes ( Cdh5 , Cldn5 ) and increased proinflammatory markers ( RT1-Da , Cd74 ), termed ‘inflammatory’ ECs. The second was an arterial cluster that exhibited reduced expression of Dll4 and increased Cxcl12 and Fn1 , termed ‘activated’ arterial ECs. Both populations emerging at 1-week post SU, persisting throughout PAH progression. While many EC populations showed marked differential gene expression (DGE) at 1 week, the activated arterial cluster was the only cluster showing progression of DGE throughout progression of PAH. Receptor-ligand analysis with NicheNet identified activated arterial ECs as a top receiver cell responding to multiple ligands, including Bmp4/5 , Col4a1 , and Vegfa/c, which were largely derived from mural fibroblasts. Conclusion: Emergence of inflammatory and activated arterial ECs likely contribute to vascular remodelling associated with PAH promoted by cross-talk with lung stromal cells.

Abstract 9504: Endothelial Shear Stress Metrics Correlate With Inflammatory Markers at the Culprit Site of Erosion in Patients With an Acute Coronary Syndrome: An OPTICO-ACS Substudy

Introduction: The pathobiological mechanisms of coronary plaque erosion are unclear. Low endothelial shear stress (ESS) is a proinflammatory/proatherogenic stimulus associated with coronary plaque progression/destabilization. Intravascular imaging studies suggest that high ESS gradient (low ESS areas adjacent to high ESS areas), and steepness of plaque upslope/downslope correlate with plaque erosion. We investigated the relationship of local fluid hemodynamics to the inflammatory microenvironment at the culprit site of erosion in patients with an acute coronary syndrome. Hypothesis: ESS metrics associate with proinflammatory/proatherogenic cells and cytokines, and contribute to plaque erosion. Methods: We studied 30 patients with erosion from the OPTIcal-COherence Tomography in Acute Coronary Syndrome study (OPTICO-ACS). OCT images were segmented, co-registered with the angiogram to create a 3D-reconstruction of the coronary artery. ESS metrics were calculated by Computational Fluid Dynamics. Systemic and local blood samples and thrombectomy specimens were collected at the culprit lesion and analyzed by flow cytometry-based immunophenotyping and plasma cytokine and chemokine profiling, and statistically tested for correlations of continuous variables using Spearman rank correlation (r). Results: Proinflammatory cytokines (IL6, MIP-1, IL1β, IL2) and local concentration of T-cells, including subsets of T-cells (CD4+, CD8+, and NKT-cells), were significantly higher at the culprit site of erosion and correlate with local adverse ESS metrics (Min ESS, Max ESS, Plaque Topographical Slope) (Table). Conclusion: Biomechanical features likely trigger activation of the adaptive immune system, including T-lymphocytes and their cytotoxic effector molecules. These results provide novel insights into the links between fluid hemodynamics, inflammatory activation, and mechanisms involved in the pathogenesis of coronary plaque erosion.

Do Chronic Low Back Pain and Chronic Widespread Pain differ in their association with Depression Symptoms in the 1958 British Cohort?

Depression frequently coexists with chronic pain. Contemporary models suggest that these conditions share pathobiological mechanisms, prompting a need to investigate their temporal association. This investigation aimed to explore two distinctly different chronic pain conditions, and their cross-sectional and prospective associations with depression. Self-reported information was available on chronic widespread pain (CWP), chronic low back pain (CLBP) (45 years), and depression symptoms (45 and 50 years) from up to 9,377 participants in the 1958 British cohort. Depression symptom outcomes were derived by "Clinical Interview Schedule-Revised" (45 years) and "Short Form-36" (50 years). Relationships between both chronic pain conditions and depression symptoms were investigated by fitting four separate logistic regression models, each with varying levels of covariate adjustment, including depression at baseline. CWP was associated with depression symptoms cross-sectionally (odds ratio [OR] = 2.04, 95% confidence interval [CI] 1.65, 2.52; P < 0.001, n = 7,629), and prospectively when fully adjusted for baseline, sociodemographic, lifestyle, and health covariates (OR = 1.45, 95% CI 1.17, 1.80; P = < 0.001, n = 6,275). CLBP was associated with depression symptoms prospectively (full model: OR = 1.28, 95% CI 1.01, 1.61; P = 0.04, n = 6,288). In fully adjusted models the prospective association of CWP with depression symptoms was more heavily influenced by our covariates than CLBP with depression symptoms. Pain may be a stressor from which depression can arise. Development of depression may be differentially dependant upon the type of pain experienced. Screening for depression symptoms among individuals with both chronic pain conditions is indicated and should be repeated over time.

The FES Gene at the 15q26 Coronary-Artery-Disease Locus Inhibits Atherosclerosis.

Genome-wide association studies have discovered a link between genetic variants on human chromosome 15q26.1 and increased coronary artery disease (CAD) susceptibility; however, the underlying pathobiological mechanism is unclear. This genetic locus contains the FES (FES proto-oncogene, tyrosine kinase) gene encoding a cytoplasmic protein-tyrosine kinase involved in the regulation of cell behavior. We investigated the effect of the 15q26.1 variants on FES expression and whether FES plays a role in atherosclerosis. Analyses of isogenic monocytic cell lines generated by CRISPR (clustered regularly interspaced short palindromic repeats)-mediated genome editing showed that monocytes with an engineered 15q26.1 CAD risk genotype had reduced FES expression. Small-interfering-RNA-mediated knockdown of FES promoted migration of monocytes and vascular smooth muscle cells. A phosphoproteomics analysis showed that FES knockdown altered phosphorylation of a number of proteins known to regulate cell migration. Single-cell RNA-sequencing revealed that in human atherosclerotic plaques, cells that expressed FES were predominately monocytes/macrophages, although several other cell types including smooth muscle cells also expressed FES. There was an association between the 15q26.1 CAD risk genotype and greater numbers of monocytes/macrophage in human atherosclerotic plaques. An animal model study demonstrated that Fes knockout increased atherosclerotic plaque size and within-plaque content of monocytes/macrophages and smooth muscle cells, in apolipoprotein E-deficient mice fed a high fat diet. We provide substantial evidence that the CAD risk variants at the 15q26.1 locus reduce FES expression in monocytes and that FES depletion results in larger atherosclerotic plaques with more monocytes/macrophages and smooth muscle cells. This study is the first demonstration that FES plays a protective role against atherosclerosis and suggests that enhancing FES activity could be a potentially novel therapeutic approach for CAD intervention.

Distinct Phenotypic Consequences of Pathogenic Mutants Associated with Late-Onset Retinal Degeneration

A pathologic feature of late-onset retinal degeneration caused by the S163R mutation in C1q-tumor necrosis factor-5 (C1QTNF5) is the presence of unusually thick deposits between the retinal pigmented epithelium (RPE) and the vascular choroid, considered a hallmark of this disease. Following its specific expression in mouse RPE, the S163R mutant exhibits a reversed polarized distribution relative to the apically secreted wild-type C1QTNF5, and forms widespread, prominent deposits that gradually increase in size with aging. The current study shows that S163R deposits expand to a considerable thickness through a progressive increase in the basolateral RPE membrane, substantially raising the total RPE height, and enabling their clear imaging as a distinct hyporeflective layer by noninvasive optical coherence tomography in advanced age animals. This phenotype bears a striking resemblance to ocular pathology previously documented in patients harboring the S163R mutation. Therefore, a similar viral vector-based gene delivery approach was used to also investigate the behavior of P188T and G216C, two novel pathogenic C1QTNF5 mutants recently reported in patients for which histopathologic data are lacking. Both mutants primarily impacted the RPE/photoreceptor interface and did not generate basal laminar deposits. Distinct distribution patterns and phenotypic consequences of C1QTNF5 mutants were observed invivo, which suggested that multiple pathobiological mechanisms contribute to RPE dysfunction and vision loss in this disorder.

Proteome profiling of whole plasma and plasma-derived extracellular vesicles facilitates the detection of tissue biomarkers in the non-obese diabetic mouse.

The mechanism by which pancreatic beta cells are destroyed in type 1 diabetes (T1D) remains to be fully understood. Recent observations indicate that the disease may arise because of different pathobiological mechanisms (endotypes). The discovery of one or several protein biomarkers measurable in readily available liquid biopsies (e.g. blood plasma) during the pre-diabetic period may enable personalized disease interventions. Recent studies have shown that extracellular vesicles (EVs) are a source of tissue proteins in liquid biopsies. Using plasma samples collected from pre-diabetic non-obese diabetic (NOD) mice (an experimental model of T1D) we addressed if combined analysis of whole plasma samples and plasma-derived EV fractions increases the number of unique proteins identified by mass spectrometry (MS) compared to the analysis of whole plasma samples alone. LC-MS/MS analysis of plasma samples depleted of abundant proteins and subjected to peptide fractionation identified more than 2300 proteins, while the analysis of EV-enriched plasma samples identified more than 600 proteins. Of the proteins detected in EV-enriched samples, more than a third were not identified in whole plasma samples and many were classified as either tissue-enriched or of tissue-specific origin. In conclusion, parallel profiling of EV-enriched plasma fractions and whole plasma samples increases the overall proteome depth and facilitates the discovery of tissue-enriched proteins in plasma. If applied to plasma samples collected longitudinally from the NOD mouse or from models with other pathobiological mechanisms, the integrated proteome profiling scheme described herein may be useful for the discovery of new and potentially endotype specific biomarkers in T1D.

A review of pathobiological mechanisms and potential application of medicinal plants for vascular aging: focus on endothelial cell senescence

Endothelial cell (EC) senescence plays a pivotal role in aging and is essential for the pathomechanism of aging-related diseases. Drugs targeting cellular senescence, such as senolytic or senomorphic drugs, may prevent aging and age-related diseases, but these bullets remain undeveloped to target EC senescence. Some medicinal plants may have an anti-senescence property but remain undiscovered. Deep learning has become an emerging approach for drug discovery by simply analyzing cellular morphology-based deep learning. This precious tool would be useful for screening the herb candidate in senescent EC rejuvenescence. Of note, several medicinal plants that can be found in Indonesia such as Curcuma longa L., Piper retrofractum, Guazuma ulmifolia Lam, Centella asiatica (L.) Urb., and Garcinia mangostana L. might potentially possess an anti-senescence effect. This review highlighted the importance of targeting EC senescence, the use of deep learning for medicinal plant screening, and some potential anti-senescence plants originating from Indonesia.

Dysregulated autophagy-related genes in septic cardiomyopathy: Comprehensive bioinformatics analysis based on the human transcriptomes and experimental validation.

Septic cardiomyopathy (SCM) is severe organ dysfunction caused by sepsis that is associated with poor prognosis, and its pathobiological mechanisms remain unclear. Autophagy is a biological process that has recently been focused on SCM, yet the current understanding of the role of dysregulated autophagy in the pathogenesis of SCM remains limited and uncertain. Exploring the molecular mechanisms of disease based on the transcriptomes of human pathological samples may bring the closest insights. In this study, we analyzed the differential expression of autophagy-related genes in SCM based on the transcriptomes of human septic hearts, and further explored their potential crosstalk and functional pathways. Key functional module and hub genes were identified by constructing a protein–protein interaction network. Eight key genes (CCL2, MYC, TP53, SOD2, HIF1A, CTNNB1, CAT, and ADIPOQ) that regulate autophagy in SCM were identified after validation in a lipopolysaccharide (LPS)-induced H9c2 cardiomyoblast injury model, as well as the autophagic characteristic features. Furthermore, we found that key genes were associated with abnormal immune infiltration in septic hearts and have the potential to serve as biomarkers. Finally, we predicted drugs that may play a protective role in SCM by regulating autophagy based on our results. Our study provides evidence and new insights into the role of autophagy in SCM based on human septic heart transcriptomes, which would be of great benefit to reveal the molecular pathological mechanisms and explore the diagnostic and therapeutic targets for SCM.

LB1038 Development of experimental models for hidradenitis suppurativa (HS)

HS is inflammatory skin disease with painful, deep-seated, inflamed lesions in the apocrine gland-bearing skin areas. The lack of an animal model, which could faithfully recapitulate most disease features, is a major impediment in defining HS pathobiology and developing effective treatment. In this study, we developed experimental HS models to elucidate the underlying mechanisms of HS pathobiology, and screen potent drug molecules. Keratinocyte cultures from HS skin provide one such model. Profiling of gene signatures showed that these keratinocytes retain the expression of many inflammatory and cell signaling signature genes altered in HS skin and these signatures remained intact up to three passages.

Immunotherapy-Based Treatments of Hepatocellular Carcinoma: AJR Expert Panel Narrative Review.

The advent of immunotherapy for patients with hepatocellular carcinoma (HCC) has changed the treatment landscape and conferred a survival benefit on patients with advanced HCC, who typically have a very poor prognosis. The most pronounced improvements in response, as documented by standardized response criteria based on CT or MRI, have been achieved when immunotherapy is combined with other systemic or locoregional therapies. Immune checkpoint inhibitor treatments result in unique patterns on CT and MRI that challenge the application of conventional response criteria such as RECIST, modified RECIST, and European Association for the Study of the Liver criteria. Thus, newer criteria have been developed to gauge therapy response or disease progression for patients receiving immunotherapy, including immune-related RECIST (iRECIST) and immune-modified RECIST (imRECIST), though these remain unvalidated. In this review, we describe the current landscape of immunotherapeutic agents used for HCC, summarize the results of published studies, review the pathobiologic mechanisms that provide a rationale for the use of these agents, and report on the status of response assessment for immunotherapy either alone or in combination with other treatment options. Finally, consensus statements are provided to inform radiologists about essential considerations in the era of a rapidly changing treatment paradigm for patients with HCC.

Senescence in pulmonary arterial hypertension: is there a link?

Cellular senescence has been recognized as a promising target in the treatment of many cardiovascular diseases. The pathways involved in the development of senescence share many similarities with pathobiological mechanisms of pulmonary arterial hypertension (PAH). But the potential of senolytics to improve pulmonary hemodynamics and to reduce vascular remodelling in PAH has thus far not been investigated in depth. PAH does not seem to be a disease of only young people since the mean age of PAH patients is constantly increasing. Changes in expression of senescence biomarkers related to cell cycle arrest, namely upregulation of the tumour suppressor protein p53 and the cell cycle inhibitors p16ink4A an p21cip1 as well as an increase in apoptosis resistance biomarker Bcl2 (B-cell lymphoma 2) and development of senescence-associated phenotype characterized by excessive production of matrix metalloproteinase 2 and interleukin 6 were demonstrated in PAH patients. Initiatives to link the senescence-modulating effect of certain compounds to clinically relevant outcomes in PAH are still limited. Further exploration of the role of senescence in the pathobiology of PAH may point to new relevant treatment strategies. Identification of the cell-specific senescence biomarkers which can be used in vivo, could further promote identification of clinically relevant pathways and design of clinical studies which will help to establish effective therapeutic use of senolytic compounds.

Systematic Review of Existing Stroke Guidelines: Case for a Change.

Methods We systematically searched for guideline recommendation on the day-to-day use of peripheral inflammatory markers such as NLR published in the English language between January 1, 2005, and October 2020. Any other evidence of system biology-based approach or recommendation was explored within the selected guidelines for this scoping review. Only the latest guideline per writing group was selected. Each guideline was analyzed independently by 2 to 4 authors to determine clinical scenarios explained/given, scientific evidence used, and recommendations presented in the context of system biology. Results The scoping review found 2,911 titles at the beginning of the search. Final review included with 15 guidelines. Stroke-related organizations wrote sixty-five percent of the guidelines while national ministries wrote a fewer number of guidelines. We were primarily interested in recommendations for acute management in AIS published in the English language. Fifteen eligible guidelines were identified from 15 different countries/regions. None of the guidelines recommended the routine use of peripheral markers of inflammation, such as NLR, among their acute assessment and management recommendations. None of the existing guidelines explored the system biology approach to one of the most complex diseases affecting the human brain, stroke. Conclusions This systematic review has identified a significant evidence-practice gap in all existing national stroke guidelines published in English medium as of October 2020. These guidelines included the only current “living stroke guidelines,” stroke guidelines from Australia with a real opportunity to modernize the living stroke guidelines with systems biology approach, and provide 2020 vision towards better stroke care globally. Investigation of complex disease such as stroke is best served through a systems biology approach. One of the easiest places to start is simple blood tests such as total white cell count and NLR. Systems biology approach point us towards simple tools such immune-inflammatory index (SII) and serial systemic immune inflammatory indices (SSIIi) which should pave the way for the stroke physician community address the challenges in systems biology approach in stroke care. These challenges include translating bench research to the bedside, managing big data (continuous pulse, blood pressure, sleep, oxygen saturation, progressive changes in NLR, SII, SSIIi, etc.). Working with an interdisciplinary team also provides a distinct advantage. Recent adoption of historic WHO-IGAP calls for immediate action. The 2022 World Brain Day campaign on Brain Health for All is the perfect opportunity to raise awareness and start the process.

Chronic Thromboembolic Pulmonary Hypertension.

Chronic thromboembolic pulmonary hypertension (CTEPH), defined as precapillary pulmonary hypertension (PH) by right heart catheterization and imaging consistent with chronic thromboembolism, is a long-term complication of pulmonary embolism (PE). Pathobiological mechanisms involve pulmonary artery occlusion from organized thromboembolic material despite at least three months of uninterrupted therapeutic anticoagulation followingacute PE and secondary microvasculopathy. Delay in diagnosis and management of CTEPH is associated with poor outcomes. High clinical suspicion,comprehensiveassessment of residual dyspnea or exercise intolerance in the aftermath of PE andaccurate interpretation ofcomputed tomography pulmonary angiography (CTPA) are pivotal steps inthe diagnosis. Ventilation-perfusion (V/Q) scan is the preferred initial radiologicscreening tool as normal V/Q essentiallyrules outCTEPH. Any mismatched perfusion defect on the V/Q scan in the setting of PH or any finding compatible with chronic thromboembolism on CTPA should prompt referral to an expert CTEPH center. Once the diagnosis is verified, all eligible patients should be offered pulmonary thromboendarterectomy (PTE). Pulmonary vasodilators or balloon pulmonary angioplasty are safe and effective in inoperable or post-PTE persistent/recurrent CTEPH. During the course of their disease, a patient may receive a combination of treatments, at times consisting of all three strategies. Lifelong therapeutic anticoagulation is recommended for CTEPH.

Comparison of biochemical, microbial and mucosal mRNA expression in bile acid diarrhoea and irritable bowel syndrome with diarrhoea

ObjectiveThere are altered mucosal functions in irritable bowel syndrome with diarrhoea (IBS-D); ~30% of patients with IBS-D have abnormal bile acid (BA) metabolism (ABAM) and diarrhoea (summarised as BAD).AimTo compare...

The Emerging Role of Extracellular Vesicles Detected in Different Biological Fluids in COPD.

The pathogenesis of chronic obstructive pulmonary disease (COPD) is characterized by complex cellular and molecular mechanisms, not fully elucidated so far. It involves inflammatory cells (monocytes/macrophages, neutrophils, lymphocytes), cytokines, chemokines and, probably, new players yet to be clearly identified and described. Chronic local and systemic inflammation, lung aging and cellular senescence are key pathological events in COPD development and progression over time. Extracellular vesicles (EVs), released by virtually all cells both as microvesicles and exosomes into different biological fluids, are involved in intercellular communication and, therefore, represent intriguing players in pathobiological mechanisms (including those characterizing aging and chronic diseases); moreover, the role of EVs as biomarkers in different diseases, including COPD, is rapidly gaining recognition. In this review, after recalling the essential steps of COPD pathogenesis, we summarize the current evidence on the roles of EVs collected in different biological mediums as biomarkers in COPD and as potential players in the specific mechanisms leading to disease development. We will also briefly review the data on EV as potential therapeutic targets and potential therapeutic agents.

Progressive pulmonary fibrosis in a murine model of Hermansky-Pudlak syndrome

BackgroundHPS-1 is a genetic type of Hermansky-Pudlak syndrome (HPS) with highly penetrant pulmonary fibrosis (HPSPF), a restrictive lung disease that is similar to idiopathic pulmonary fibrosis (IPF). Hps1ep/ep (pale ear) is a naturally occurring HPS-1 mouse model that exhibits high sensitivity to bleomycin-induced pulmonary fibrosis (PF). Traditional methods of administering bleomycin as an intratracheal (IT) route to induce PF in this model often lead to severe acute lung injury and high mortality rates, complicating studies focusing on pathobiological mechanisms or exploration of therapeutic options for HPSPF.MethodsTo develop a murine model of HPSPF that closely mimics the progression of human pulmonary fibrosis, we investigated the pulmonary effects of systemic delivery of bleomycin in Hps1ep/ep mice using a subcutaneous minipump and compared results to oropharyngeal delivery of bleomycin.ResultsOur study revealed that systemic delivery of bleomycin induced limited, acute inflammation that resolved. The distinct inflammatory phase preceded a slow, gradually progressive fibrogenesis that was shown to be both time-dependent and dose-dependent. The fibrosis phase exhibited characteristics that better resembles human disease with focal regions of fibrosis that were predominantly found in peribronchovascular areas and in subpleural regions; central lung areas contained relatively less fibrosis.ConclusionThis model provides a preclinical tool that will allow researchers to study the mechanism of pulmonary fibrosis in HPS and provide a platform for the development of therapeutics to treat HPSPF. This method can be applied on studies of IPF or other monogenic disorders that lead to pulmonary fibrosis.

Transcriptomics Coupled to Proteomics Reveals Novel Targets for the Protective Role of Spermine in Diabetic Cardiomyopathy.

Background Diabetic cardiomyopathy (DbCM) is the main complication and the cause of high mortality of diabetes. Exploring the transcriptomics and proteomics of DbCM is of great significance for understanding the biology of the disease and for guiding new therapeutic targets for the potential therapeutic effect of spermine (SPM). Methods and Results By using a mouse DbCM model, we analyzed the overall transcriptome and proteome of the myocardium, before/after treatment with SPM. The general state and cardiac structure and function changes of each group were also compared. Diabetes induced an increased blood glucose and serum triglyceride content, a decreased body weight, serum insulin level, and cardiac function-related indexes, accompanied by disrupted myocardial tissue morphology and ultrastructure damage. Using RNA sequencing (RNA-seq), we identified thousands of differentially expressed genes (DEGs) in DbCM with or without SPM treatment. Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis demonstrated that the DEGs were significantly enriched in lipid metabolism and amino acid metabolism pathways. Specifically, quantitative real-time PCR (qRT-PCR) confirmed that SPM protected DbCM by reversing the expressions of lipid metabolism and amino acid metabolism-related genes, including Alox15, Gm13033, pla2g12a, Ptges, Pnpla2, and Acot1. To further reveal the pathogenesis of DbCM, we used proteome-based data-independent acquisition (DIA) and identified 139 differentially expressed proteins (DEPs) with 67 being upregulated and 72 being downregulated in DbCM. Venn intersection analysis showed 37 coexpressed genes and proteins in DbCM, including 29 upregulation and 8 downregulation in DbCM. In the protein-protein interaction (PPI) network constructed by the STRING database, the metabolism-related coexpressed genes and proteins, such as Acot2, Ephx2, Cyp1a1, Comt, Acox1, Hadhb, Hmgcs2, Acot1, Inmt, and Cat, can interact with the identified DEGs and DEPs. Conclusion The biomarkers and canonical pathways identified in this study may hold the key to understand the mechanisms of DbCM pathobiology and provide new targets for the therapeutic effect of SPM against DbCM by targeting lipid and amino acid metabolism pathways.

Genetic and Epigenetic Constructs of Progressive Supranuclear Palsy.

Progressive supranuclear palsy (PSP) is a rapidly progressive primary tauopathy characterized by vertical gaze palsy, postural instability, and mild dementia. PSP shows high clinical and pathologic heterogeneity. Although a few risk factors exist, such as advanced age and environmental toxins, the precise etiology remains largely elusive. Compelling evidence now suggests that genetic background plays a pivotal role in the pathogenetic pathways of PSP. Notably, PSP is genetically and phenotypically a complex disorder. Given the tau pathology, several studies in the past have identified microtubule-associated protein tau (MAPT) gene mutations/variations and its haplotype as the major genetic risk factor of PSP, both in the sporadic and the familial forms. Subsequently, genome-wide association studies (GWAS) also identified several novel risk variants. However, these genetic risk determinants fail to explain the pathogenetic basis of PSP and its phenotypic spectrum in majority of the cases. Some genetic variants are known to confer the risk, while others seem to act as modifier genes. Besides the complex genetic basis of PSP, the pathobiological mechanisms, differential diagnosis, and management of patients with PSP have further been complicated by genetic conditions that mimic the phenotypes of PSP. This is now becoming increasingly apparent that interactions between genetic and environmental factors significantly contribute to PSP development. Further, the effect of environmental factors seems to be mediated through epigenetic modifications. Herein, we provide a comprehensive overview of the genetic and epigenetic constructs of PSP and highlight the relevance of genetic and epigenetic findings in the pathobiology of PSP.