Transcriptomic changes during TGF-β-mediated differentiation of airway fibroblasts to myofibroblasts

Tumor biomechanical stiffness by magnetic resonance elastography predicts surgical outcomes and identifies biomarkers in vestibular schwannoma and meningioma

Variations in the biomechanical stiffness of brain tumors can not only influence the difficulty of surgical resection but also impact postoperative outcomes. In a prospective, single-blinded study, we utilize pre-operative magnetic resonance elastography (MRE) to predict the stiffness of intracranial tumors intraoperatively and assess the impact of increased tumor stiffness on clinical outcomes following microsurgical resection of vestibular schwannomas (VS) and meningiomas. MRE measurements significantly correlated with intraoperative tumor stiffness and baseline hearing status of VS patients. Additionally, MRE stiffness was elevated in patients that underwent sub-total tumor resection compared to gross total resection and those with worse postoperative facial nerve function. Furthermore, we identify tumor microenvironment biomarkers of increased stiffness, including αSMA + myogenic fibroblasts, CD163 + macrophages, and HABP (hyaluronic acid binding protein). In a human VS cell line, a dose-dependent upregulation of HAS1-3, enzymes responsible for hyaluronan synthesis, was observed following stimulation with TNFα, a proinflammatory cytokine present in VS. Taken together, MRE is an accurate, non-invasive predictor of tumor stiffness in VS and meningiomas. VS with increased stiffness portends worse preoperative hearing and poorer postoperative outcomes. Moreover, inflammation-mediated hyaluronan deposition may lead to increased stiffness.

YiQi GuBen formula alleviates airway inflammation and airway remodeling in OVA-induced asthma mice through TLR4/NF-κB signaling pathway

BACKGROUND

We aim to investigate the effect of YiQi GuBen formula (YQGB) on airway inflammation and airway remodeling in the ovalbumin (OVA)-induced asthma model to further explore the potential mechanisms of YQGB in treating allergic asthma.

METHODS

Mice were divided into five groups randomly (n = 10): the control group, OVA group, OVA + Dex (0.1 mg/kg) group, OVA + low-dose (1.1 g/kg) YQGB group, and OVA + high-dose (2.2 g/kg) YQGB group. Inflammatory cell count and IgE were detected in bronchoalveolar lavage fluid (BALF). Lung tissue histopathology was observed by using H&E, PAS, Masson, and immunohistochemistry staining. qRT-PCR and western blot were applied to analyze key genes and proteins associated with TLR4 and NF-κB signaling pathways.

RESULTS

In OVA-induced asthma mice, YQGB decreased eosinophils and IgE in BALF. YQGB alleviated the OVA-induced inflammatory infiltration and declined IL-4, IL-5, IL-13, Eotaxin, ECP, GM-CSF, LTC4, and LTD4. YQGB attenuated the OVA-induced goblet cell metaplasia and mucus hypersecretion. YQGB mitigated the OVA-induced subepithelial fibrosis and lowered TGF-β1, E-Cadherin, Vimentin, and Fibronectin. YQGB ameliorated the OVA-induced airway smooth muscle thickening and lessened α-SMA and PDGF levels. YQGB reduced the expression of TLR4, MyD88, TRAF6, IκBα, and p65 mRNAs, and IκBα and p-p65 protein levels were also reduced.

CONCLUSION

YQGB exhibits the anti-asthma effect by reducing airway inflammation and airway remodeling through suppressing TLR4/NF-κB signaling pathway, and is worth promoting clinically.

Single-cell senescence identification reveals senescence heterogeneity, trajectory, and modulators

Cellular senescence underlies many aging-related pathologies, but its heterogeneity poses challenges for studying and targeting senescent cells. We present here a machine learning program senescent cell identification (SenCID), which accurately identifies senescent cells in both bulk and single-cell transcriptome. Trained on 602 samples from 52 senescence transcriptome datasets spanning 30 cell types, SenCID identifies six major senescence identities (SIDs). Different SIDs exhibit different senescence baselines, stemness, gene functions, and responses to senolytics. SenCID enables the reconstruction of senescent trajectories under normal aging, chronic diseases, and COVID-19. Additionally, when applied to single-cell Perturb-seq data, SenCID helps reveal a hierarchy of senescence modulators. Overall, SenCID is an essential tool for precise single-cell analysis of cellular senescence, enabling targeted interventions against senescent cells.

Retrospective identification of cell-intrinsic factors that mark pluripotency potential in rare somatic cells

Pluripotency can be induced in somatic cells by the expression of OCT4, KLF4, SOX2, and MYC. Usually only a rare subset of cells reprogram, and the molecular characteristics of this subset remain unknown. We apply retrospective clone tracing to identify and characterize the rare human fibroblasts primed for reprogramming. These fibroblasts showed markers of increased cell cycle speed and decreased fibroblast activation. Knockdown of a fibroblast activation factor identified by our analysis increased the reprogramming efficiency. We provide evidence for a unified model in which cells can move into and out of the primed state over time, explaining how reprogramming appears deterministic at short timescales and stochastic at long timescales. Furthermore, inhibiting the activity of LSD1 enlarged the pool of cells that were primed for reprogramming. Thus, even homogeneous cell populations can exhibit heritable molecular variability that can dictate whether individual rare cells will reprogram or not.

Substance P Increases STAT6-Mediated Transcription Activation of Lymphocyte Cytosolic Protein 2 to Sustain M2 Macrophage Predominance in Pediatric Asthma

Substance P (SP) is a neuropeptide released by neurons and participates in various biological processes, including inflammation. M2 macrophages are major immune cells associated with type 2 inflammation in asthma. This study investigated the effect of SP on macrophage phenotype in pediatric asthma and the underpinning factors. Asthmatic children exhibited an increased level of SP, along with a higher proportion of M2 macrophages in their bronchoalveolar lavage fluid. Flow cytometry revealed that SP treatment enhanced the M2 polarization of 12-O-tetradecanoylphorbol 13-acetate-treated THP-1 cells (macrophages) in vitro. By contrast, the administration of a neutralizing antibody of SP reduced the M2 macrophage population, mitigated inflammatory cell infiltration in mouse lung tissues, and decreased the population of immune cells in the mouse bronchoalveolar lavage fluid. SP up-regulated the expression of STAT6, which, in turn, activated the transcription of lymphocyte cytosolic protein 2 (LCP2). The population of macrophages and allergic inflammatory responses in mice were reduced by STAT6 inhibition but restored by LCP2 overexpression. Collectively, the present study demonstrated that SP sustains M2 macrophage predominance and allergic inflammation in pediatric asthma by enhancing STAT6-dependent transcription activation of LCP2.

Rhinovirus protease cleavage of nucleoporins: perspective on implications for airway remodeling

Human Rhinoviruses (RV) are a major cause of common colds and infections in early childhood and can lead to subsequent development of asthma via an as yet unknown mechanism. Asthma is a chronic inflammatory pulmonary disease characterized by significant airway remodeling. A key component of airway remodeling is the transdifferentiation of airway epithelial and fibroblast cells into cells with a more contractile phenotype. Interestingly, transforming growth factor-beta (TGF-β), a well characterized inducer of transdifferentiation, is significantly higher in airways of asthmatics compared to non-asthmatics. RV infection induces TGF-β signaling, at the same time nucleoporins (Nups), including Nup153, are cleaved by RV proteases disrupting nucleocytoplasmic transport. As Nup153 regulates nuclear export of SMAD2, a key intermediate in the TGF-β transdifferentiation pathway, its loss of function would result in nuclear retention of SMAD2 and dysregulated TGF-β signaling. We hypothesize that RV infection leads to increased nuclear SMAD2, resulting in sustained TGF-β induced gene expression, priming the airway for subsequent development of asthma. Our hypothesis brings together disparate studies on RV, asthma and Nup153 with the aim to prompt new research into the role of RV infection in development of asthma.

Role of transforming growth factor-β in airway remodelling in bronchiolitis obliterans

Airway remodelling is the main pathological mechanism of bronchiolitis obliterans (BO). Several studies have found that transforming growth factor-β (TGF-β) expression is increased in BO during airway remodelling, where it plays an important role in various biological processes by binding to its receptor complex to activate multiple signalling proteins and pathways. This review examines the role of TGF-β in airway remodelling in BO and its potential as a therapeutic target, highlighting the mechanisms of TGF-β activation and signalling, cellular targets of TGF-β actions, and research progress in TGF-β signalling and TGF-β-mediated processes.

Prostaglandin E2 attenuates lung fibroblast differentiation via inactivation of yes-associated protein signaling

Prostaglandin E2 (PGE2 ) has been implicated in counteracting fibroblast differentiation by TGFβ1 during pulmonary fibrosis. However, the precise mechanism is not well understood. We show here that PGE2 via EP2 R and EP4 R inhibits the expression of mechanosensory molecules Lysyl Oxidase Like 2 (LOXL2), myocardin-related transcription factor A (MRTF-A), ECM proteins, plasminogen activation inhibitor 1 (PAI-1), fibronectin (FN), α-smooth muscle actin (α-SMA), and redox sensor (nicotinamide adenine dinucleotide phosphate (NADPH) oxidase 4 (NOX4)) required for TGFβ1-mediated fibroblast differentiation. We further demonstrate that PGE2 inhibits fibrotic signaling via Yes-associated protein (YAP) but does so independently from its actions on SMAD phosphorylation and conserved cylindromatosis (CYLD; deubiquitinase) expression. Mechanistically, PGE2 phosphorylates/inactivates YAP downstream of EP2 R/Gαs and restrains its translocation to the nucleus, thus inhibiting its interaction with TEA domain family members (TEADs) and transcription of fibrotic genes. Importantly, pharmacological or siRNA-mediated inhibition of YAP significantly downregulates TGFβ1-mediated fibrotic gene expression and myofibroblast formation. Notably, YAP expression is upregulated in the lungs of D. farinae-treated wild type (WT) mice relative to saline-treated WT mice. Our results unravel a unique role for PGE2 -YAP interactions in fibroblast differentiation, and that PGE2 /YAP inhibition can be used as a novel therapeutic target in the treatment of pathological conditions associated with myofibroblasts like asthma.

Rhinovirus induces airway remodeling: what are the physiological consequences?

BACKGROUND

Rhinovirus infections commonly evoke asthma exacerbations in children and adults. Recurrent asthma exacerbations are associated with injury-repair responses in the airways that collectively contribute to airway remodeling. The physiological consequences of airway remodeling can manifest as irreversible airway obstruction and diminished responsiveness to bronchodilators. Structural cells of the airway, including epithelial cells, smooth muscle, fibroblasts, myofibroblasts, and adjacent lung vascular endothelial cells represent an understudied and emerging source of cellular and extracellular soluble mediators and matrix components that contribute to airway remodeling in a rhinovirus-evoked inflammatory environment.

MAIN BODY

While mechanistic pathways associated with rhinovirus-induced airway remodeling are still not fully characterized, infected airway epithelial cells robustly produce type 2 cytokines and chemokines, as well as pro-angiogenic and fibroblast activating factors that act in a paracrine manner on neighboring airway cells to stimulate remodeling responses. Morphological transformation of structural cells in response to rhinovirus promotes remodeling phenotypes including induction of mucus hypersecretion, epithelial-to-mesenchymal transition, and fibroblast-to-myofibroblast transdifferentiation. Rhinovirus exposure elicits airway hyperresponsiveness contributing to irreversible airway obstruction. This obstruction can occur as a consequence of sub-epithelial thickening mediated by smooth muscle migration and myofibroblast activity, or through independent mechanisms mediated by modulation of the β2 agonist receptor activation and its responsiveness to bronchodilators. Differential cellular responses emerge in response to rhinovirus infection that predispose asthmatic individuals to persistent signatures of airway remodeling, including exaggerated type 2 inflammation, enhanced extracellular matrix deposition, and robust production of pro-angiogenic mediators.

CONCLUSIONS

Few therapies address symptoms of rhinovirus-induced airway remodeling, though understanding the contribution of structural cells to these processes may elucidate future translational targets to alleviate symptoms of rhinovirus-induced exacerbations.

Antler stem cell exosomes alleviate pulmonary fibrosis via inhibiting recruitment of monocyte macrophage, rather than polarization of M2 macrophages in mice

Pulmonary fibrosis (PF), a chronic interstitial lung disease, is characterized by over-abundant deposition of extracellular matrix consisting mainly of collagen I. In previous studies, we demonstrated that deer antler stem cells (AnSCs), a novel type of adult stem cell, are capable of significantly down-regulating collagen formation in different organs and tissues and speculated that they could effectively treat PF via reducing collagen deposition in the lung tissue. In the present study, we found that administration of AnSCs improved the survival rate of PF mice and reduced lung fibrosis, collagen deposition and myofibroblast differentiation. The effects of AnSC treatment were significantly better than the positive control (adipose-derived stem cells). Interestingly, AnSC-Exos were almost equally effective as AnSCs in treating PF, suggesting that the effects of AnSCs on reduction of PF may be mainly through a paracrine mechanism. Further, AnSC-Exos reduced the number of M2 macrophages, a type of macrophage that secrets pro-fibrotic factors to accelerate fibrotic progression, in the lung tissues. In vitro experiments showed that the effects of AnSC-Exos on macrophage modulation were likely achieved via inhibition of the recruitment of circulating monocyte-derived macrophages (reducing the number of macrophages), rather than via inhibition of M2 polarization of macrophages. Inhibition of macrophage recruitment by AnSCs may be achieved indirectly via inhibiting CCL7 expression in fibroblasts; both let-7b and let-7a were highly enriched in AnSC-Exos and may play a critical role in the inhibition of CCL7 expression of fibroblasts. Collectively, the use of antler stem cells or their exosomes opens up a novel strategy for PF treatment in the clinical setting.

Unraveling the link between PTBP1 and severe asthma through machine learning and association rule mining method

Severe asthma is a chronic inflammatory airway disease with great therapeutic challenges. Understanding the genetic and molecular mechanisms of severe asthma may help identify therapeutic strategies for this complex condition. RNA expression data were analyzed using a combination of artificial intelligence methods to identify novel genes related to severe asthma. Through the ANOVA feature selection approach, 100 candidate genes were selected among 54,715 mRNAs in blood samples of patients with severe asthmatic and healthy groups. A deep learning model was used to validate the significance of the candidate genes. The accuracy, F1-score, AUC-ROC, and precision of the 100 genes were 83%, 0.86, 0.89, and 0.9, respectively. To discover hidden associations among selected genes, association rule mining was applied. The top 20 genes including the PTBP1, RAB11FIP3, APH1A, and MYD88 were recognized as the most frequent items among severe asthma association rules. The PTBP1 was found to be the most frequent gene associated with severe asthma among those 20 genes. PTBP1 was the gene most frequently associated with severe asthma among candidate genes. Identification of master genes involved in the initiation and development of asthma can offer novel targets for its diagnosis, prognosis, and targeted-signaling therapy.

Substrate Stiffness Modulates TGF-β Activation and ECM-Associated Gene Expression in Fibroblasts

Transforming growth factor-β (TGF-β) is a multifunctional cytokine that regulates the expression of ECM-associated genes during early injury. Tissue fibrosis development is driven by synergistic cues between the evolving biochemical and mechanical milieu. Few studies have addressed the role of substrate stiffness on TGF-β activity and extracellular matrix (ECM)-associated genes. We used a commercial formulation of polydimethylsiloxane (PDMS) to fabricate substrates of 40 kPa, 300 kPa, and 1.5 MPa stiffness, and cultured the HMF3S fibroblasts on substrates. We quantified TGF-β protein secreted by HMF3S cells on different substrates using a TGF-β responsive promoter reporter assay. We also tested for variations in gene expression levels on the substrates using RT-PCR and Western blotting and determined the MMP-2 and MMP-9 activities with gelatin zymography. The results showed that TGF-β protein activation was significantly compromised at lower stiffnesses. The expression of integrin α5 decreased on lower stiffness substrates and correlated with inefficient TGF-β protein activation. Collagen I, collagen III, and MMP-2 expression levels were lower on softer substrates; there was little MMP-9 activity on all substrates. Cell and nuclear morphologies were more rounded on compliant substrates, correlating with increased tubulin expression. Proliferations were higher on stiffer substrates, whereas cells on softer substrates showed cell cycle arrest. These results demonstrated critical feedback mechanisms between substrate stiffness and ECM regulation by fibroblasts, relevant in fibrosis.

Rev-erbα agonists suppresses TGFβ1-induced fibroblast-to-myofibroblast transition and pro-fibrotic phenotype in human lung fibroblasts

Idiopathic pulmonary fibrosis (IPF) is an interstitial lung disease characterized by excessive scarring of the lungs that can lead to respiratory failure and death. Lungs of patients with IPF demonstrate excessive deposition of extracellular matrix (ECM) and an increased presence of pro-fibrotic mediators such as transforming growth factor-beta 1 (TGFβ1), which is a major driver of fibroblast-to-myofibroblast transition (FMT). Current literature supports that circadian clock dysfunction plays an essential role in the pathophysiology of various chronic inflammatory lung diseases such as asthma, chronic obstructive pulmonary disease, and IPF. The circadian clock transcription factor Rev-erbα is encoded by Nr1d1 that regulates daily rhythms of gene expression linked to immunity, inflammation, and metabolism. However, investigations into the potential roles of Rev-erbα in TGFβ-induced FMT and ECM accumulation are limited. In this study, we utilized several novel small molecule Rev-erbα agonists (GSK41122, SR9009, and SR9011) and a Rev-erbα antagonist (SR8278) to determine the roles of Rev-erbα in regulating TGFβ1-induced FMT and pro-fibrotic phenotypes in human lung fibroblasts. WI-38 cells were either pre-treated/co-treated with or without Rev-erbα agonist/antagonist along with TGFβ1. After 48 h, the following parameters were evaluated: secretion of COL1A1 (Slot-Blot analysis) and IL-6 (ELISA) into condition media, expressions of α-smooth muscle actin (αSMA: immunostaining and confocal microscopy), and pro-fibrotic proteins (αSMA and COL1A1 by immunoblotting), as well as gene expression of pro-fibrotic targets (qRT-PCR: Acta2, Fn1, and Col1a1). Results revealed that Rev-erbα agonists inhibited TGFβ1-induced FMT (αSMA and COL1A1), and ECM production (reduced gene expression of Acta2, Fn1, and Col1a1), and decreased pro-inflammatory cytokine IL-6 release. The Rev-erbα antagonist promoted TGFβ1-induced pro-fibrotic phenotypes. These findings support the potential of novel circadian clock-based therapeutics, such as Rev-erbα agonist, for the treatment and management of fibrotic lung diseases and disorders.

SEQUIN is an R/Shiny framework for rapid and reproducible analysis of RNA-seq data

SEQUIN is a web-based application (app) that allows fast and intuitive analysis of RNA sequencing data derived for model organisms, tissues, and single cells. Integrated app functions enable uploading datasets, quality control, gene set enrichment, data visualization, and differential gene expression analysis. We also developed the iPSC Profiler, a practical gene module scoring tool that helps measure and compare pluripotent and differentiated cell types. Benchmarking to other commercial and non-commercial products underscored several advantages of SEQUIN. Freely available to the public, SEQUIN empowers scientists using interdisciplinary methods to investigate and present transcriptome data firsthand with state-of-the-art statistical methods. Hence, SEQUIN helps democratize and increase the throughput of interrogating biological questions using next-generation sequencing data with single-cell resolution.

Fibrotic remodeling and tissue regeneration mechanisms define the therapeutic potential of human muscular progenitors

Fibrosis is an intrinsic biological reaction toward the challenges of tissue injury that is implicated in the wound-healing process. Although it is useful to efficiently mitigate the damage, progression of fibrosis is responsible for the morbidity and mortality occurring in a variety of diseases. Because of lacking effective treatments, there is an emerging need for exploring antifibrotic strategies. Cell therapy based on stem/progenitor cells is regarded as a promising approach for treating fibrotic diseases. Appropriate selection of cellular sources is required for beneficial results. Muscle precursor cells (MPCs) are specialized progenitors harvested from skeletal muscle for conducting muscle regeneration. Whether they are also effective in regulating fibrosis has seldom been explored and merits further investigation. MPCs were successfully harvested from all human samples regardless of demographic backgrounds. The extracellular matrices remodeling was enhanced through the paracrine effects mediated by MPCs. The suppression effects on fibrosis were confirmed in vivo when MPCs were transplanted into the diseased animals with oral submucous fibrosis. The data shown here revealed the potential of MPCs to be employed to simultaneously regulate both processes of fibrosis and tissue regeneration, supporting them as the promising cell candidates for development of the cell therapy for antifibrosis and tissue regeneration.

Retrospective identification of intrinsic factors that mark pluripotency potential in rare somatic cells

Pluripotency can be induced in somatic cells by the expression of the four "Yamanaka" factors OCT4, KLF4, SOX2, and MYC. However, even in homogeneous conditions, usually only a rare subset of cells admit reprogramming, and the molecular characteristics of this subset remain unknown. Here, we apply retrospective clone tracing to identify and characterize the individual human fibroblast cells that are primed for reprogramming. These fibroblasts showed markers of increased cell cycle speed and decreased fibroblast activation. Knockdown of a fibroblast activation factor identified by our analysis led to increased reprogramming efficiency, identifying it as a barrier to reprogramming. Changing the frequency of reprogramming by inhibiting the activity of LSD1 led to an enlarging of the pool of cells that were primed for reprogramming. Our results show that even homogeneous cell populations can exhibit heritable molecular variability that can dictate whether individual rare cells will reprogram or not.

LRRC15 mediates an accessory interaction with the SARS-CoV-2 spike protein

The interactions between Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) and human host factors enable the virus to propagate infections that lead to Coronavirus Disease 2019 (COVID-19). The spike protein is the largest structural component of the virus and mediates interactions essential for infection, including with the primary angiotensin-converting enzyme 2 (ACE2) receptor. We performed two independent cell-based systematic screens to determine whether there are additional proteins by which the spike protein of SARS-CoV-2 can interact with human cells. We discovered that in addition to ACE2, expression of LRRC15 also causes spike protein binding. This interaction is distinct from other known spike attachment mechanisms such as heparan sulfates or lectin receptors. Measurements of orthologous coronavirus spike proteins implied the interaction was functionally restricted to SARS-CoV-2 by accessibility. We localized the interaction to the C-terminus of the S1 domain and showed that LRRC15 shares recognition of the ACE2 receptor binding domain. From analyzing proteomics and single-cell transcriptomics, we identify LRRC15 expression as being common in human lung vasculature cells and fibroblasts. Levels of LRRC15 were greatly elevated by inflammatory signals in the lungs of COVID-19 patients. Although infection assays demonstrated that LRRC15 alone is not sufficient to permit viral entry, we present evidence that it can modulate infection of human cells. This unexpected interaction merits further investigation to determine how SARS-CoV-2 exploits host LRRC15 and whether it could account for any of the distinctive features of COVID-19.

Amygdalin alleviated TGF-β-induced epithelial-mesenchymal transition in bronchial epithelial cells

OBJECTIVE

Transforming growth factor-beta TGF-β-induced epithelial-mesenchymal transition (EMT) in bronchial epithelial cells contributes to airway wall remodeling in asthma. This study aims to explore the role of amygdalin, an active ingredient in bitter almonds, in TGF-β-induced EMT in bronchial epithelial cells and to elucidate the possible mechanisms underlying its biological effects.

METHODS

An asthmatic mouse model was established through ovalbumin induction. Primary mouse bronchial epithelial cells and a human bronchial epithelial cell line were incubated with transforming growth factor-beta (TGF-β) to induce EMT, whose phenotype of cells was evaluated by the expressions of EMT markers [alpha-smooth muscle actin (α-SMA), vimentin, and fibronectin] and cell migration capacity. A co-immunoprecipitation assay was performed to assess the ubiquitination of heparanase (HPSE).

RESULTS

In asthmatic model mice, amygdalin treatment relieved airway wall remodeling and decreased expressions of EMT markers (α-SMA and vimentin). In TGF-β-treated bronchial epithelial cells, amygdalin treatment decreased the mRNA and protein levels of EMT markers (α-SMA, vimentin, and fibronectin) without impairing cell viability. Through the Swiss Target Prediction database, HPSE was screened as a candidate downstream target for amygdalin. HPSE overexpression further promoted TGF-β-induced EMT while the HPSE inhibitor suppressed TGF-β-induced EMT in bronchial epithelial cells. In addition, HPSE overexpression reversed the inhibitory effect of amygdalin on TGF-β-induced EMT in bronchial epithelial cells. The following mechanism exploration revealed that amygdalin downregulated HPSE expression by enhancing ubiquitination.

CONCLUSION

Our study showed that amygdalin inhibited TGF-β-induced EMT in bronchial epithelial cells and found that the anti-EMT activity of amygdalin might be related to its regulatory effect on HPSE expression.

The promising therapeutic effects of metformin on metabolic reprogramming of cancer-associated fibroblasts in solid tumors

Tumor-infiltrated lymphocytes are exposed to many toxic metabolites and molecules in the tumor microenvironment (TME) that suppress their anti-tumor activity. Toxic metabolites, such as lactate and ketone bodies, are produced mainly by catabolic cancer-associated fibroblasts (CAFs) to feed anabolic cancer cells. These catabolic and anabolic cells make a metabolic compartment through which high-energy metabolites like lactate can be transferred via the monocarboxylate transporter channel 4. Moreover, a decrease in molecules, including caveolin-1, has been reported to cause deep metabolic changes in normal fibroblasts toward myofibroblast differentiation. In this context, metformin is a promising drug in cancer therapy due to its effect on oncogenic signal transduction pathways, leading to the inhibition of tumor proliferation and downregulation of key oncometabolites like lactate and succinate. The cross-feeding and metabolic coupling of CAFs and tumor cells are also affected by metformin. Therefore, the importance of metabolic reprogramming of stromal cells and also the pivotal effects of metformin on TME and oncometabolites signaling pathways have been reviewed in this study.

TRPM7 restrains plasmin activity and promotes transforming growth factor-β1 signaling in primary human lung fibroblasts

Sustained exposure of the lung to various environmental or occupational toxins may eventually lead to pulmonary fibrosis, a devastating disease with no cure. Pulmonary fibrosis is characterized by excessive deposition of extracellular matrix (ECM) proteins such as fibronectin and collagens. The peptidase plasmin degrades the ECM, but protein levels of the plasmin activator inhibitor-1 (PAI-1) are increased in fibrotic lung tissue, thereby dampening plasmin activity. Transforming growth factor-β1 (TGF-β1)-induced activation of SMAD transcription factors promotes ECM deposition by enhancing collagen, fibronectin and PAI-1 levels in pulmonary fibroblasts. Hence, counteracting TGF-β1-induced signaling is a promising approach for the therapy of pulmonary fibrosis. Transient receptor potential cation channel subfamily M Member 7 (TRPM7) supports TGF-β1-promoted SMAD signaling in T-lymphocytes and the progression of fibrosis in kidney and heart. Thus, we investigated possible effects of TRPM7 on plasmin activity, ECM levels and TGF-β1 signaling in primary human pulmonary fibroblasts (pHPF). We found that two structurally unrelated TRPM7 blockers enhanced plasmin activity and reduced fibronectin or PAI-1 protein levels in pHPF under basal conditions. Further, TRPM7 blockade strongly inhibited fibronectin and collagen deposition induced by sustained TGF-β1 stimulation. In line with these data, inhibition of TRPM7 activity diminished TGF-β1-triggered phosphorylation of SMAD-2, SMAD-3/4-dependent reporter activation and PAI-1 mRNA levels. Overall, we uncover TRPM7 as a novel supporter of TGF-β1 signaling in pHPF and propose TRPM7 blockers as new candidates to control excessive ECM levels under pathophysiological conditions conducive to pulmonary fibrosis.

Insights into potential mechanisms of asthma patients with COVID-19: A study based on the gene expression profiling of bronchoalveolar lavage fluid

Background

The 2019 novel coronavirus disease (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is currently a major challenge threatening the global healthcare system. Respiratory virus infection is the most common cause of asthma attacks, and thus COVID-19 may contribute to an increase in asthma exacerbations. However, the mechanisms of COVID-19/asthma comorbidity remain unclear.

Methods

The “Limma” package or “DESeq2” package was used to screen differentially expressed genes (DEGs). Alveolar lavage fluid datasets of COVID-19 and asthma were obtained from the GEO and GSV database. A series of analyses of common host factors for COVID-19 and asthma were conducted, including PPI network construction, module analysis, enrichment analysis, inference of the upstream pathway activity of host factors, tissue-specific analysis and drug candidate prediction. Finally, the key host factors were verified in the GSE152418 and GSE164805 datasets.

Results

192 overlapping host factors were obtained by analyzing the intersection of asthma and COVID-19. FN1, UBA52, EEF1A1, ITGB1, XPO1, NPM1, EGR1, EIF4E, SRSF1, CCR5, PXN, IRF8 and DDX5 as host factors were tightly connected in the PPI network. Module analysis identified five modules with different biological functions and pathways. According to the degree values ranking in the PPI network, EEF1A1, EGR1, UBA52, DDX5 and IRF8 were considered as the key cohost factors for COVID-19 and asthma. The H₂O₂, VEGF, IL-1 and Wnt signaling pathways had the strongest activities in the upstream pathways. Tissue-specific enrichment analysis revealed the different expression levels of the five critical host factors. LY294002, wortmannin, PD98059 and heparin might have great potential to evolve into therapeutic drugs for COVID-19 and asthma comorbidity. Finally, the validation dataset confirmed that the expression of five key host factors were statistically significant among COVID-19 groups with different severity and healthy control subjects.

Conclusions

This study constructed a network of common host factors between asthma and COVID-19 and predicted several drugs with therapeutic potential. Therefore, this study is likely to provide a reference for the management and treatment for COVID-19/asthma comorbidity.

Pathways linked to unresolved inflammation and airway remodelling characterize the transcriptome in two independent severe asthma cohorts

Background and objective

Severe asthma (SA) is a heterogeneous disease. Transcriptomic analysis contributes to the understanding of pathogenesis necessary for developing new therapies. We sought to identify and validate mechanistic pathways of SA across two independent cohorts.

Methods

Transcriptomic profiles from U‐BIOPRED and Australian NOVocastrian Asthma cohorts were examined and grouped into SA, mild/moderate asthma (MMA) and healthy controls (HCs). Differentially expressed genes (DEGs), canonical pathways and gene sets were identified as central to SA mechanisms if they were significant across both cohorts in either endobronchial biopsies or induced sputum.

Results

Thirty‐six DEGs and four pathways were shared across cohorts linking to tissue remodelling/repair in biopsies of SA patients, including SUMOylation, NRF2 pathway and oxidative stress pathways. MMA presented a similar profile to HCs. Induced sputum demonstrated IL18R1 as a shared DEG in SA compared with healthy subjects. We identified enrichment of gene sets related to corticosteroid treatment; immune‐related mechanisms; activation of CD4⁺ T cells, mast cells and IL18R1; and airway remodelling in SA.

Conclusion

Our results identified differentially expressed pathways that highlight the role of CD4⁺ T cells, mast cells and pathways linked to ongoing airway remodelling, such as IL18R1, SUMOylation and NRF2 pathways, as likely active mechanisms in the pathogenesis of SA.

Transcriptome analysis from endobronchial biopsies and induced sputum from two independent cohorts of adults with severe asthma (SA) (U‐BIOPRED and Australian NOVocastrian Asthma cohort) demonstrated shared differentially expressed pathways previously linked to persistent unresolved inflammation and novel mechanisms of airway remodelling, which may represent potential novel mechanistic pathways involved in the pathogenesis of SA.

See relatededitorial

Novel insights from a multiomics dissection of the hayflick limit

The process wherein dividing cells exhaust proliferative capacity and enter into replicative senescence has become a prominent model for cellular aging in vitro. Despite decades of study, this cellular state is not fully understood in culture and even much less so during aging. Here, we revisit Leonard Hayflick’s original observation of replicative senescence in WI-38 human lung fibroblasts equipped with a battery of modern techniques including RNA-seq, single-cell RNA-seq, proteomics, metabolomics, and ATAC-seq. We find evidence that the transition to a senescent state manifests early, increases gradually, and corresponds to a concomitant global increase in DNA accessibility in nucleolar and lamin associated domains. Furthermore, we demonstrate that senescent WI-38 cells acquire a striking resemblance to myofibroblasts in a process similar to the epithelial to mesenchymal transition (EMT) that is regulated by t YAP1/TEAD1 and TGF-β2. Lastly, we show that verteporfin inhibition of YAP1/TEAD1 activity in aged WI-38 cells robustly attenuates this gene expression program.

Pathobiology of Airway Remodeling in Asthma: The Emerging Role of Integrins

Airway remodeling is a complex clinical feature of asthma that involves long-term disruption and modification of airway architecture, which contributes significantly to airway hyperresponsiveness (AHR) and lung function decline. It is characterized by thickening of the airway smooth muscle layer, deposition of a matrix below the airway epithelium, resulting in subepithelial fibrosis, changes within the airway epithelium, leading to disruption of the barrier, and excessive mucous production and angiogenesis within the airway wall. Airway remodeling contributes to stiffer and less compliant airways in asthma and leads to persistent, irreversible airflow obstruction. Current asthma treatments aim to reduce airway inflammation and exacerbations but none are targeted towards airway remodeling. Inhibiting the development of airway remodeling or reversing established remodeling has the potential to dramatically improve symptoms and disease burden in asthmatic patients. Integrins are a family of transmembrane heterodimeric proteins that serve as the primary receptors for extracellular matrix (ECM) components, mediating cell-cell and cell-ECM interactions to initiate intracellular signaling cascades. Cells present within the lungs, including structural and inflammatory cells, express a wide and varying range of integrin heterodimer combinations and permutations. Integrins are emerging as an important regulator of inflammation, repair, remodeling, and fibrosis in the lung, particularly in chronic lung diseases such as asthma. Here, we provide a comprehensive summary of the current state of knowledge on integrins in the asthmatic airway and how these integrins promote the remodeling process, and emphasize their potential involvement in airway disease.

Molecular Pathogenesis and the Possible Role of Mitochondrial Heteroplasmy in Thoracic Aortic Aneurysm

Thoracic aortic aneurysm (TAA) is a life-threatening condition associated with high mortality, in which the aortic wall is deformed due to congenital or age-associated pathological changes. The mechanisms of TAA development remain to be studied in detail, and are the subject of active research. In this review, we describe the morphological changes of the aortic wall in TAA. We outline the genetic disorders associated with aortic enlargement and discuss the potential role of mitochondrial pathology, in particular mitochondrial DNA heteroplasmy, in the disease pathogenesis.

TGF-β1/SMOC2/AKT and ERK axis regulates proliferation, migration, and fibroblast to myofibroblast transformation in lung fibroblast, contributing with the asthma progression

Background

Asthma is a common chronic respiratory disease that influences 300 million people all over the world. However, the pathogenesis of asthma has not been fully elucidated. It has been reported that transforming growth factor-β (TGF-β) can activate myofibroblasts. Moreover, the fibroblast to myofibroblast transformation (FMT) can be triggered by TGF-β, which is a major mediator of subepithelial fibrosis. Secreted modular calcium-binding protein 2 (SMOC2) is a member of cysteine (SPARC) family and is involved in the progression of multiple diseases. However, its role in asthma remains poorly understood. RT-qPCR evaluated the expression of SMOC2. Bromodeoxyuridine assay and wound-healing assay detected the proliferation and migration of lung fibroblasts, respectively. IF staining was performed to assess the expression of α-smooth muscle actin (α-SMA). Western blot analysis detected the levels of proteins. Flow cytometry was utilized for determination of the number of myofibroblasts.

Results

We found the expression of SMOC2 was upregulated by the treatment of TGF-β1 in lung fibroblasts. In addition, SMOC2 promoted the proliferation and migration of lung fibroblasts. More importantly, SMOC2 accelerated FMT of lung fibroblasts. Furthermore, SMOC2 was verified to control the activation of AKT and ERK. Rescue assays showed that the inhibition of AKT and ERK pathway reversed the promoting effect of SMOC2 overexpression on proliferation, migration and FMT in lung fibroblasts.

Conclusions

This work demonstrated that SMOC2 modulated TGF-β1-induced proliferation, migration and FMT in lung fibroblasts and may promote asthma, which potentially provided a novel therapeutic target for the management of asthma.

Supplementary Information

The online version contains supplementary material available at 10.1186/s41065-021-00213-w.

Classical and Non-classical Fibrosis Phenotypes Are Revealed by Lung and Cardiac Like Microvascular Tissues On-Chip

Fibrosis, a hallmark of many cardiac and pulmonary diseases, is characterized by excess deposition of extracellular matrix proteins and increased tissue stiffness. This serious pathologic condition is thought to stem majorly from local stromal cell activation. Most studies have focused on the role of fibroblasts; however, the endothelium has been implicated in fibrosis through direct and indirect contributions. Here, we present a 3D vascular model to investigate vessel-stroma crosstalk in normal conditions and following induced fibrosis. Human-induced pluripotent stem cell-derived endothelial cells (hiPSC-ECs) are co-cultured with (and without) primary human cardiac and lung fibroblasts (LFs) in a microfluidic device to generate perfusable microvasculature in cardiac- and pulmonary-like microenvironments. Endothelial barrier function, vascular morphology, and matrix properties (stiffness and diffusivity) are differentially impacted by the presence of stromal cells. These vessels (with and without stromal cells) express inflammatory cytokines, which could induce a wound-healing state. Further treatment with transforming growth factor-β (TGF-β) induced varied fibrotic phenotypes on-chip, with LFs resulting in increased stiffness, lower MMP activity, and increased smooth muscle actin expression. Taken together, our work demonstrates the strong impact of stromal-endothelial interactions on vessel formation and extravascular matrix regulation. The role of TGF-β is shown to affect co-cultured microvessels differentially and has a severe negative impact on the endothelium without stromal cell support. Our human 3D in vitro model has the potential to examine anti-fibrotic therapies on patient-specific hiPSCs in the future.

Current Pharmacological Strategies for Duchenne Muscular Dystrophy

Duchenne muscular dystrophy (DMD) is a lethal, X-linked neuromuscular disorder caused by the absence of dystrophin protein, which is essential for muscle fiber integrity. Loss of dystrophin protein leads to recurrent myofiber damage, chronic inflammation, progressive fibrosis, and dysfunction of muscle stem cells. There is still no cure for DMD so far and the standard of care is principally limited to symptom relief through glucocorticoids treatments. Current therapeutic strategies could be divided into two lines. Dystrophin-targeted therapeutic strategies that aim at restoring the expression and/or function of dystrophin, including gene-based, cell-based and protein replacement therapies. The other line of therapeutic strategies aims to improve muscle function and quality by targeting the downstream pathological changes, including inflammation, fibrosis, and muscle atrophy. This review introduces the important developments in these two lines of strategies, especially those that have entered the clinical phase and/or have great potential for clinical translation. The rationale and efficacy of each agent in pre-clinical or clinical studies are presented. Furthermore, a meta-analysis of gene profiling in DMD patients has been performed to understand the molecular mechanisms of DMD.

Knockdown of NOVA1 inhibits inflammation and migration of asthmatic airway smooth muscle cells to regulate PTEN/Akt pathway by targeting PTBP1

NOVA1 (neuro-oncological ventral antigen 1) is a neuron specific RNA binding protein, belonging to the Nova family, which plays an important role in various diseases. However, the role of NOVA1 in childhood asthma remains unclear. This study was aimed to investigate the role of NOVA1 in TGF-β1-induced ASMCs proliferation and migration as well as the potential mechanisms. In our study, the NOVA1 expression was significantly increased in asthmatic tissues and TGF-β1-induced ASMCs. Inhibition of NOVA1 significantly inhibited TGF-β1-induced ASMCs cell proliferation and migration, and alleviates TGF-β1-induced inflammation. NOVA1 positively regulated the PTBP1 expression and si-NOVA1 inhibited the activation of PTEN/AKT signal pathway. Importantly, the overexpression of PTBP1 partially reversed the effect of NOVA1 on cell viability, migration, inflammation and the activation of PTEN/AKT signal pathway. Generally, our study demonstrated that si-NOVA1 inhibited TGF-β1-induced inflammation and migration in ASMCs through PTBP1/PTEN/AKT pathway. Therefore, inhibition of NOVA1 may be useful for the prevention or treatment of asthma airway remodeling.

Fibrosis, the Bad Actor in Cardiorenal Syndromes: Mechanisms Involved

Cardiorenal syndrome is a term that defines the complex bidirectional nature of the interaction between cardiac and renal disease. It is well established that patients with kidney disease have higher incidence of cardiovascular comorbidities and that renal dysfunction is a significant threat to the prognosis of patients with cardiac disease. Fibrosis is a common characteristic of organ injury progression that has been proposed not only as a marker but also as an important driver of the pathophysiology of cardiorenal syndromes. Due to the relevance of fibrosis, its study might give insight into the mechanisms and targets that could potentially be modulated to prevent fibrosis development. The aim of this review was to summarize some of the pathophysiological pathways involved in the fibrotic damage seen in cardiorenal syndromes, such as inflammation, oxidative stress and endoplasmic reticulum stress, which are known to be triggers and mediators of fibrosis.

Transforming Growth Factor-Beta1 and Human Gingival Fibroblast-to-Myofibroblast Differentiation: Molecular and Morphological Modifications

After oral mucosal injury, the healing response following specific steps that lead to wound closure and to tissue repair. Multiple cell populations are involved in this process; in particular, fibroblasts play a key role in the production of extracellular matrix (ECM). During wound healing the remodeling of ECM is a key stage to restore the tissue functionality through multifunctional fibroblast populations that are placed in the connective tissues of gingiva and periodontal ligament. Notably, a fibroblast sub-type (myofibroblast) is centrally involved in collagen synthesis and fibrillar remodeling. The present work evidenced the role of Transforming Growth Factor-beta1 (TGF-β1) to mediate human gingival fibroblasts (hGFs) differentiation into myofibroblasts derived from gingival fibroblasts (myo-hGFs). The morphological and functional features were analyzed through Confocal Laser Scanning Microscopy (CLSM), flow cytometry, and western blotting analyses. The specific markers, such as alpha-Smooth Muscle Actin (α-SMA), Vimentin, E-cadherin, β-catenin, and Smad 2/3, were modulated in myo-hGFs after the induction with TGF-β1, at different time points (24, 48, and 72 h). After 72 h of treatment TGF-β1 operates as an inducer of hGFs into myo-hGFs differentiation. We propose that TGF-β1 may promote in vitro the fibroblasts-to-myofibroblasts transition via the morphological and molecular modifications, as the induction of α-SMA, Vimentin, E-cadherin, β-catenin, and Smad 2/3.

Extracellular vesicles derived from umbilical cord mesenchymal stromal cells alleviate pulmonary fibrosis by means of transforming growth factor-β signaling inhibition

Background

Pulmonary fibrosis (PF), the end point of interstitial lung diseases, is characterized by myofibroblast over differentiation and excessive extracellular matrix accumulation, leading to progressive organ dysfunction and usually a terminal outcome. Studies have shown that umbilical cord-derived mesenchymal stromal cells (uMSCs) could alleviate PF; however, the underlying mechanism remains to be elucidated.

Methods

The therapeutic effects of uMSC-derived extracellular vesicles (uMSC-EVs) on PF were evaluated using bleomycin (BLM)-induced mouse models. Then, the role and mechanism of uMSC-EVs in inhibiting myofibroblast differentiation were investigated in vivo and in vitro.

Results

Treatment with uMSC-EVs alleviated the PF and enhanced the proliferation of alveolar epithelial cells in BLM-induced mice, thus improved the life quality, including the survival rate, body weight, fibrosis degree, and myofibroblast over differentiation of lung tissue. Moreover, these effects of uMSC-EVs on PF are likely achieved by inhibiting the transforming growth factor-β (TGF-β) signaling pathway, evidenced by decreased expression levels of TGF-β2 and TGF-βR2. Using mimics of uMSC-EV-specific miRNAs, we found that miR-21 and miR-23, which are highly enriched in uMSC-EVs, played a critical role in inhibiting TGF-β2 and TGF-βR2, respectively.

Conclusion

The effects of uMSCs on PF alleviation are likely achieved via EVs, which reveals a new role of uMSC-EV-derived miRNAs, opening a novel strategy for PF treatment in the clinical setting.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13287-021-02296-8.

AITC inhibits fibroblast-myofibroblast transition via TRPA1-independent MAPK and NRF2/HO-1 pathways and reverses corticosteroids insensitivity in human lung fibroblasts

Background

Little is known on the role of transient receptor potential ankyrin 1 (TRPA1) in fibroblast—myofibroblast transition (FMT) that can lead to airway remodeling which is a major problem for severe asthma and fibrosis. Thus, this study investigated the effect of TRPA1 modulators on transforming growth factor beta 1(TGF-β1) -treated lung fibroblasts.

Methods

MRC-5 cells were preincubated with TGF-β1 for 24 h. TRPA1 agonist or antagonist were added and further incubated for 24 h. The changes in TRPA1 and alpha-smooth muscle actin (α-SMA) expressions by stimuli were evaluated using qRT-PCR, western blot and immunohistochemical analyses. Statistical significance was determined by using one- or two-way ANOVA, followed by Bonferroni’s post hoc analysis for comparison of multiple groups and paired 2-tailed Student’s t-test between 2 groups.

Results

MRC-5 cells treated by TGF-β1 significantly upregulated α-SMA mRNA expressions (P < 0.01), but downregulated TRPA1 gene expression (P < 0.001). Post-treatment of TRPA1 activator, allyl isothiocyanate (AITC), after TGF-β1 significantly downregulated the α-SMA gene induction (P < 0.01 at 24 h), protein expression (P < 0.05) and immunoreactivity with stress fibers (P < 0.05). On the other hand, TRPA1 antagonist HC-030031 did not prevent this effect, and instead tended to facilitate the suppressive effect of AITC when co-stimulated. AITC significantly increased phosphorylated- extracellular signal-regulated kinase (ERK) 1/2 and heme oxygenase (HO)-1 protein expressions (P < 0.05) in TGF-β1-treated cells. Combined inhibition with ERK1/2 mitogen-activated protein kinase (MAPK) and nuclear factor erythroid 2-related factor (NRF2) almost completely reversed AITC-induced α-SMA suppression (P < 0.05). Dexamethasone was not able to inhibit the upregulated α-SMA induction by TGF-β1. However, AITC improved dexamethasone-insensitive myodifferentiation in the presence of the corticosteroid (P < 0.01).

Conclusion

We found that AITC exerts protective effect on TGF-β1-induced α-SMA induction by activating ERK1/2 MAPK and NRF2/HO-1 pathways in lung fibroblasts. It also overcomes corticosteroids insensitivity in TGF-β1-induced α-SMA induction. TRPA1 antagonist modulates the suppressive effect, but not prevent it. AITC and TRPA1 antagonist may be therapeutic agents in treating chronic respiratory diseases.

Signatures of Dermal Fibroblasts from RDEB Pediatric Patients

The recessive form of dystrophic epidermolysis bullosa (RDEB) is a debilitating disease caused by impairments in the junctions of the dermis and the basement membrane of the epidermis. Mutations in the COL7A1 gene induce multiple abnormalities, including chronic inflammation and profibrotic changes in the skin. However, the correlations between the specific mutations in COL7A1 and their phenotypic output remain largely unexplored. The mutations in the COL7A1 gene, described here, were found in the DEB register. Among them, two homozygous mutations and two cases of compound heterozygous mutations were identified. We created the panel of primary patient-specific RDEB fibroblast lines (FEB) and compared it with control fibroblasts from healthy donors (FHC). The set of morphological features and the contraction capacity of the cells distinguished FEB from FHC. We also report the relationships between the mutations and several phenotypic traits of the FEB. Based on the analysis of the available RNA-seq data of RDEB fibroblasts, we performed an RT-qPCR gene expression analysis of our cell lines, confirming the differential status of multiple genes while uncovering the new ones. We anticipate that our panels of cell lines will be useful not only for studying RDEB signatures but also for investigating the overall mechanisms involved in disease progression.

Regulation of cardiomyocyte fate plasticity: a key strategy for cardiac regeneration

With the high morbidity and mortality rates, cardiovascular diseases have become one of the most concerning diseases worldwide. The heart of adult mammals can hardly regenerate naturally after injury because adult cardiomyocytes have already exited the cell cycle, which subseqently triggers cardiac remodeling and heart failure. Although a series of pharmacological treatments and surgical methods have been utilized to improve heart functions, they cannot replenish the massive loss of beating cardiomyocytes after injury. Here, we summarize the latest research progress in cardiac regeneration and heart repair through altering cardiomyocyte fate plasticity, which is emerging as an effective strategy to compensate for the loss of functional cardiomyocytes and improve the impaired heart functions. First, residual cardiomyocytes in damaged hearts re-enter the cell cycle to acquire the proliferative capacity by the modifications of cell cycle-related genes or regulation of growth-related signals. Additionally, non-cardiomyocytes such as cardiac fibroblasts, were shown to be reprogrammed into cardiomyocytes and thus favor the repair of damaged hearts. Moreover, pluripotent stem cells have been shown to transform into cardiomyocytes to promote heart healing after myocardial infarction (MI). Furthermore, in vitro and in vivo studies demonstrated that environmental oxygen, energy metabolism, extracellular factors, nerves, non-coding RNAs, etc. play the key regulatory functions in cardiac regeneration. These findings provide the theoretical basis of targeting cellular fate plasticity to induce cardiomyocyte proliferation or formation, and also provide the clues for stimulating heart repair after injury.

Nano nickel oxide promotes epithelial-mesenchymal transition through transforming growth factor β1/smads signaling pathway in A549 cells

Our previous study demonstrated that nano nickel oxide (NiO) induce pulmonary fibrosis in rats and collagen excessive formation in A549 cells, which mechanism was related with the increasing transforming growth factor β1 (TGF-β1) secretion. However, it remains unclear understanding the role of TGF-β1 in collagen excessive formation. Here, we found nano NiO could directly promote epithelial-mesenchymal transition (EMT) via the TGF-β1/Smads pathway in A549 cells. First, cytotoxicity induced by nano NiO has a dose- and time-dependent manner according to methylthiaozol tetrazolium assay. Second, nano NiO led to the increased contents of type I collagen (Col-I), TGF-β1, p-Smad2, p-Smad3, alpha-smooth muscle actin (α-SMA), vimentin, and fibronectin, indicating Smads pathway activation and EMT occurence. Third, to verify whether TGF-β1 activated Smads signaling pathway and EMT occurence, A549 cells were exposed to nano NiO and TGF-β1 inhibitors (10 μM SB431542). The results showed that TGF-β1 inhibitors alleviated the nano NiO-induced cytotoxicity and Col-I excessive formation. Meanwhile, TGF-β1 inhibitors reversed the proteins expression trends of Col-I, p-Smad2, p-Smad3, α-SMA, vimentin, fibronectin, and E-cadherin. These observations suggested that EMT occurrence via TGF-β1/Smads pathway might play an important role in the collagen excessive formation induced by nano NiO in A549 cells.

Asthma genomics and pharmacogenomics

In this review, we summarize recent published work interrogating the relationship between genetic variation or gene expression regulation across the genome and asthma or asthma treatment outcomes. This includes 11 genome-wide association studies of asthma phenotypes that collectively identified 64 novel loci; transcriptome-wide asthma association studies which identified genes involved in virus recognition, bacterial infection, lung tissue remodeling, eosinophilic and neutrophilic inflammation and genes in the chromosome 17q12 asthma susceptibility locus; and three epigenome-wide studies of asthma that had robust sample sizes and replicated findings. We also highlight pharmacogenomic studies of corticosteroids, bronchodilator response to albuterol and zileuton, although finding from these studies may still be preliminary due to their relatively small sample sizes and limited availability of replication cohorts.

Leonurus sibiricus root extracts decrease airway remodeling markers expression in fibroblasts

Bronchial asthma is believed to be provoked by the interaction between airway inflammation and remodeling. Airway remodeling is a complex and poorly understood process, and controlling it appears key for halting the progression of asthma and other obstructive lung diseases. Plants synthesize a number of valuable compounds as constitutive products and as secondary metabolites, many of which have curative properties. The aim of this study was to evaluate the anti-remodeling properties of extracts from transformed and transgenic Leonurus sibiricus roots with transformed L. sibiricus roots extract with transcriptional factor AtPAP1 overexpression (AtPAP1). Two fibroblast cell lines, Wistar Institute-38 (WI-38) and human fetal lung fibroblast (HFL1), were incubated with extracts from transformed L. sibiricus roots (TR) and roots with transcriptional factor AtPAP1 over-expression (AtPAP1 TR). Additionally, remodeling conditions were induced in the cultures with rhinovirus 16 (HRV16). The expressions of metalloproteinase 9 (MMP)-9, tissue inhibitor of metalloproteinases 1 (TIMP-1), arginase I and transforming growth factor (TGF)-β were determined by quantitative polymerase chain reaction (qPCR) and immunoblotting methods. AtPAP1 TR decreased arginase I and MMP-9 expression with no effect on TIMP-1 or TGF-β mRNA expression. This extract also inhibited HRV16-induced expression of arginase I, MMP-9 and TGF-β in both cell lines (P < 0·05) Our study shows for the first time to our knowledge, that transformed AtPAP1 TR extract from L. sibiricus root may affect the remodeling process. Its effect can be attributed an increased amount of phenolic acids such as: chlorogenic acid, caffeic acid or ferulic acid and demonstrates the value of biotechnology in medicinal research.

Prolonged Scar-in-a-Jar: an in vitro screening tool for anti-fibrotic therapies using biomarkers of extracellular matrix synthesis

BACKGROUND

Idiopathic pulmonary fibrosis (IPF) is a rapidly progressing disease with challenging management. To find novel effective therapies, better preclinical models are needed for the screening of anti-fibrotic compounds. Activated fibroblasts drive fibrogenesis and are the main cells responsible for the accumulation of extracellular matrix (ECM). Here, a prolonged Scar-in-a-Jar assay was combined with clinically validated biochemical markers of ECM synthesis to evaluate ECM synthesis over time. To validate the model as a drug screening tool for novel anti-fibrotic compounds, two approved compounds for IPF, nintedanib and pirfenidone, and a compound in development, omipalisib, were tested.

METHODS

Primary human lung fibroblasts from healthy donors were cultured for 12 days in the presence of ficoll and were stimulated with TGF-β1 with or without treatment with an ALK5/TGF-β1 receptor kinase inhibitor (ALK5i), nintedanib, pirfenidone or the mTOR/PI3K inhibitor omipalisib (GSK2126458). Biomarkers of ECM synthesis were evaluated over time in cell supernatants using ELISAs to assess type I, III, IV, V and VI collagen formation (PRO-C1, PRO-C3, PRO-C4, PRO-C5, PRO-C6), fibronectin (FBN-C) deposition and α-smooth muscle actin (α-SMA) expression.

RESULTS

TGF-β1 induced synthesis of PRO-C1, PRO-C6 and FBN-C as compared with unstimulated fibroblasts at all timepoints, while PRO-C3 and α-SMA levels were not elevated until day 8. Elevated biomarkers were reduced by suppressing TGF-β1 signalling with ALK5i. Nintedanib and omipalisib were able to reduce all biomarkers induced by TGF-β1 in a concentration dependent manner, while pirfenidone had no effect on α-SMA.

CONCLUSIONS

TGF-β1 stimulated synthesis of type I, III and VI collagen, fibronectin and α-SMA but not type IV or V collagen. Synthesis was increased over time, although temporal profiles differed, and was modulated pharmacologically by ALK5i, nintedanib, pirfenidone and omipalisib. This prolonged 12-day Scar-in-a-Jar assay utilising biochemical markers of ECM synthesis provides a useful screening tool for novel anti-fibrotic compounds.