scholarly journals Cellular Senescence: Pathogenic Mechanisms in Lung Fibrosis

Author(s):  
Tanyalak Parimon ◽  
Miriam Hohmann ◽  
Changfu Yao

:Pulmonary fibrosis is a chronic and fatal lung disease that significantly impacts the aging population globally. To date, anti-fibrotic, immunosuppressive, and other adjunct therapy demonstrate a limited efficacy. Advancing our understanding of pathogenic mechanisms of lung fibrosis provides a future path for the cure. Cellular senescence has gained substantial interest in the past decades due to the increased incidence of fibroproliferative lung diseases in the older age group. Furthermore, the pathologic state of cellular senescence that includes maladaptive tissue repair, decreased regeneration, and chronic inflammation resembles key features of progressive lung fibrosis. This review describes regulatory pathways of cellular senescence and discusses the current knowledge on the senescence of critical cellular players of lung fibrosis, including epithelial cells (alveolar type 2 cells, basal cells, etc.), fibroblasts, and immune cells, their phenotypic changes, and the cellular and molecular mechanisms by which these cells contribute to the pathogenesis of pulmonary fibrosis. A few challenges in the field include establishing appropriate in vivo experimental models and identifying senescence targeted signaling molecules and specific therapy to target senescent cells, known collectively as "senolytic" or “senotherapeutic” agents.

2021 ◽  
Vol 22 (12) ◽  
pp. 6214
Author(s):  
Tanyalak Parimon ◽  
Miriam S. Hohmann ◽  
Changfu Yao

Pulmonary fibrosis is a chronic and fatal lung disease that significantly impacts the aging population globally. To date, anti-fibrotic, immunosuppressive, and other adjunct therapy demonstrate limited efficacies. Advancing our understanding of the pathogenic mechanisms of lung fibrosis will provide a future path for the cure. Cellular senescence has gained substantial interest in recent decades due to the increased incidence of fibroproliferative lung diseases in the older age group. Furthermore, the pathologic state of cellular senescence that includes maladaptive tissue repair, decreased regeneration, and chronic inflammation resembles key features of progressive lung fibrosis. This review describes regulatory pathways of cellular senescence and discusses the current knowledge on the senescence of critical cellular players of lung fibrosis, including epithelial cells (alveolar type 2 cells, basal cells, etc.), fibroblasts, and immune cells, their phenotypic changes, and the cellular and molecular mechanisms by which these cells contribute to the pathogenesis of pulmonary fibrosis. A few challenges in the field include establishing appropriate in vivo experimental models and identifying senescence-targeted signaling molecules and specific therapies to target senescent cells, known collectively as “senolytic” or “senotherapeutic” agents.


2020 ◽  
Vol 11 ◽  
Author(s):  
Fei Gao ◽  
Yun Zhang ◽  
Zhizhou Yang ◽  
Mengmeng Wang ◽  
Zhiyi Zhou ◽  
...  

Arctigenin (ATG), a major bioactive substance of Fructus Arctii, counters renal fibrosis; however, whether it protects against paraquat (PQ)-induced lung fibrosis remains unknown. The present study was to determine the effect of ATG on PQ-induced lung fibrosis in a mouse model and the underlying mechanism. Firstly, we found that ATG suppressed PQ-induced pulmonary fibrosis by blocking the epithelial-mesenchymal transition (EMT). ATG reduced the expressions of Vimentin and α-SMA (lung fibrosis markers) induced by PQ and restored the expressions of E-cadherin and Occludin (two epithelial markers) in vivo and in vitro. Besides, the Wnt3a/β-catenin signaling pathway was significantly activated in PQ induced pulmonary fibrosis. Further analysis showed that pretreatment of ATG profoundly abrogated PQ-induced EMT-like phenotypes and behaviors in A549 cells. The Wnt3a/β-catenin signaling pathway was repressed by ATG treatment. The overexpression of Wnt3a could weaken the therapeutic effect of ATG in A549 cells. These findings suggested that ATG could serve as a new therapeutic candidate to inhibit or even reverse EMT-like changes in alveolar type II cells during PQ-induced lung fibrosis, and unraveled that the Wnt3a/β-catenin pathway might be a mechanistic tool for ATG to control pulmonary fibrosis.


2021 ◽  
Vol 8 ◽  
Author(s):  
Mirjam Kiener ◽  
Nuria Roldan ◽  
Carlos Machahua ◽  
Arunima Sengupta ◽  
Thomas Geiser ◽  
...  

The coronavirus disease 2019 (COVID-19) pandemic has caused considerable socio-economic burden, which fueled the development of treatment strategies and vaccines at an unprecedented speed. However, our knowledge on disease recovery is sparse and concerns about long-term pulmonary impairments are increasing. Causing a broad spectrum of symptoms, COVID-19 can manifest as acute respiratory distress syndrome (ARDS) in the most severely affected patients. Notably, pulmonary infection with Severe Acute Respiratory Syndrome coronavirus 2 (SARS-CoV-2), the causing agent of COVID-19, induces diffuse alveolar damage (DAD) followed by fibrotic remodeling and persistent reduced oxygenation in some patients. It is currently not known whether tissue scaring fully resolves or progresses to interstitial pulmonary fibrosis. The most aggressive form of pulmonary fibrosis is idiopathic pulmonary fibrosis (IPF). IPF is a fatal disease that progressively destroys alveolar architecture by uncontrolled fibroblast proliferation and the deposition of collagen and extracellular matrix (ECM) proteins. It is assumed that micro-injuries to the alveolar epithelium may be induced by inhalation of micro-particles, pathophysiological mechanical stress or viral infections, which can result in abnormal wound healing response. However, the exact underlying causes and molecular mechanisms of lung fibrosis are poorly understood due to the limited availability of clinically relevant models. Recently, the emergence of SARS-CoV-2 with the urgent need to investigate its pathogenesis and address drug options, has led to the broad application of in vivo and in vitro models to study lung diseases. In particular, advanced in vitro models including precision-cut lung slices (PCLS), lung organoids, 3D in vitro tissues and lung-on-chip (LOC) models have been successfully employed for drug screens. In order to gain a deeper understanding of SARS-CoV-2 infection and ultimately alveolar tissue regeneration, it will be crucial to optimize the available models for SARS-CoV-2 infection in multicellular systems that recapitulate tissue regeneration and fibrotic remodeling. Current evidence for SARS-CoV-2 mediated pulmonary fibrosis and a selection of classical and novel lung models will be discussed in this review.


2017 ◽  
Vol 23 (7) ◽  
pp. 615-624 ◽  
Author(s):  
Huimin Yue ◽  
Yarong Zhao ◽  
Haining Wang ◽  
Feiya Ma ◽  
Fei Liu ◽  
...  

Hirsutella sinensis, cultured in vitro, is an attractive substitute for Cordyceps sinensis as health supplement. The aim of this study was to demonstrate whether H. sinensis mycelium (HSM) attenuates murine pulmonary fibrosis induced by bleomycin and to explore the underlying molecular mechanisms. Using lung fibrosis modle induced by intratracheal instillation of bleomycin (BLM; 4 mg/kg), we observed that the administration of HSM reduced HYP, TGF-β1 and the production of several pro-fibrosis cytokines (α-smooth muscle actin, fibronectin and vimentin) in fibrotic mice lung sections. Histopathological examination of lung tissues also demonstrated that HSM improved BLM-induced pathological damage. Concurrently, HSM supplementation markedly reduced the chemotaxis of alveolar macrophages and potently suppressed the expression of inflammatory cytokines. Also, HSM influenced Th1/Th2 and Th17/Treg imbalance and blocked the phosphorylation of mTOR pathway in vivo. Alveolar epithelial A549 cells acquired a mesenchymal phenotype and an increased expression of myofibroblast markers of differentiation (vimentin and fibronectin) after treatment with TGF-β1. HSM suppressed these markers and blocked the phosphorylation of mTOR pathway in vitro. The results provide evidence supporting the use of HSM in the intervention of pulmonary fibrosis and suggest that HSM is a potential therapeutic agent for lung fibrosis.


2020 ◽  
Author(s):  
Benedikt Jaeger ◽  
Jonas Christian Schupp ◽  
Linda Plappert ◽  
Oliver Terwolbeck ◽  
Gian Kayser ◽  
...  

ABSTRACTIdiopathic pulmonary fibrosis (IPF) is a fatal disease with limited treatment options. In this study we focus on the profibrotic properties of airway basal cells (ABC) obtained from patients with IPF (IPF-ABC). Single cell RNA sequencing of bronchial brushes revealed extensive reprogramming of IPF-ABC towards a KRT17high PTENlow dedifferentiated cell type. In the 3D organoid model, compared to ABC obtained from healthy volunteers, IPF-ABC give rise to more bronchospheres, de novo bronchial structures resembling lung developmental processes, induce fibroblast proliferation and extracellular matrix deposition in co-culture. Intratracheal application of IPF-ABC into minimally injured lungs of Rag2-/- or NRG mice causes severe fibrosis, remodeling of the alveolar compartment, and formation of honeycomb cyst-like structures. Connectivity MAP analysis of scRNA seq of bronchial brushings suggested that gene expression changes in IPF-ABC can be reversed by SRC inhibition. After demonstrating enhanced SRC expression and activity in these cells, and in IPF lungs, we tested the effects of saracatinib, a potent SRC inhibitor previously studied in humans. We demonstrated that saracatinib modified in-vitro and in-vivo the profibrotic changes observed in our 3D culture system and novel mouse xenograft model.


Molecules ◽  
2019 ◽  
Vol 24 (1) ◽  
pp. 193 ◽  
Author(s):  
Yasuyoshi Miyata ◽  
Yohei Shida ◽  
Tomoaki Hakariya ◽  
Hideki Sakai

Prostate cancer is the most common cancer among men. Green tea consumption is reported to play an important role in the prevention of carcinogenesis in many types of malignancies, including prostate cancer; however, epidemiological studies show conflicting results regarding these anti-cancer effects. In recent years, in addition to prevention, many investigators have shown the efficacy and safety of green tea polyphenols and combination therapies with green tea extracts and anti-cancer agents in in vivo and in vitro studies. Furthermore, numerous studies have revealed the molecular mechanisms of the anti-cancer effects of green tea extracts. We believe that improved understanding of the detailed pathological roles at the molecular level is important to evaluate the prevention and treatment of prostate cancer. Therefore, in this review, we present current knowledge regarding the anti-cancer effects of green tea extracts in the prevention and treatment of prostate cancer, with a particular focus on the molecular mechanisms of action, such as influencing tumor growth, apoptosis, androgen receptor signaling, cell cycle, and various malignant behaviors. Finally, the future direction for the use of green tea extracts as treatment strategies in patients with prostate cancer is introduced.


2016 ◽  
Vol 29 (7-8) ◽  
pp. 476 ◽  
Author(s):  
Elisabete Coelho ◽  
Ana Magalhães ◽  
Mário Dinis-Ribeiro ◽  
Celso A. Reis

Introduction: Helicobacter pylori infection is very prevalent worldwide and is associated with the progression of the gastriccarcinogenesis cascade, being one of the main risk factors for the development of gastric carcinoma. Several factors are determinant for the infection and for the development of gastric disease, including environmental factors, host genetic factors and virulence factors of the bacteria.Material and Methods: In this review, we present an overview of the current knowledge on the determinants of the infection and on the recently described molecular mechanisms of Helicobacter pylori adhesion to the gastric mucosa, as well as its possible future therapeutic application.Results: The adhesion of Helicobacter pylori to the gastric epithelium is critical for gastric pathogenesis, allowing bacterial access to nutrients and the action of bacterial virulence factors, promoting recurrence of the infection and the progression of the gastric carcinogenesis pathway.Discussion: Eradication of Helicobacter pylori infection is the best preventive strategy available against gastric cancer, mainly if it is achieved before the development of pre-neoplastic lesions. The increase in antibiotics resistance, together with the eradication failures in some patients, has promoted the development of alternative treatments.Conclusion: The new therapeutic strategies, focused on the molecular mechanism of Helicobacter pylori adhesion, are very promising; however, future studies are needed to evaluate its in vivo efficiency and toxicity.


Cancers ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 1868 ◽  
Author(s):  
Oihane Erice ◽  
Adrian Vallejo ◽  
Mariano Ponz-Sarvise ◽  
Michael Saborowski ◽  
Arndt Vogel ◽  
...  

Cholangiocarcinoma (CCA) is a genetically and histologically complex disease with a highly dismal prognosis. A deeper understanding of the underlying cellular and molecular mechanisms of human CCA will increase our current knowledge of the disease and expedite the eventual development of novel therapeutic strategies for this fatal cancer. This endeavor is effectively supported by genetic mouse models, which serve as sophisticated tools to systematically investigate CCA pathobiology and treatment response. These in vivo models feature many of the genetic alterations found in humans, recapitulate multiple hallmarks of cholangiocarcinogenesis (encompassing cell transformation, preneoplastic lesions, established tumors and metastatic disease) and provide an ideal experimental setting to study the interplay between tumor cells and the surrounding stroma. This review is intended to serve as a compendium of CCA mouse models, including traditional transgenic models but also genetically flexible approaches based on either the direct introduction of DNA into liver cells or transplantation of pre-malignant cells, and is meant as a resource for CCA researchers to aid in the selection of the most appropriate in vivo model system.


2018 ◽  
Vol 315 (4) ◽  
pp. L563-L575 ◽  
Author(s):  
Hua Jiang ◽  
Yingzhun Chen ◽  
Tong Yu ◽  
Xiaoguang Zhao ◽  
Huitong Shan ◽  
...  

Idiopathic pulmonary fibrosis (IPF) is a devastating interstitial lung disease with increasing mortality and poor prognosis. The current understanding of the role of long noncoding RNAs (lncRNAs) in IPF remains limited. In the present study, we identified a lncRNA NONMMUT022554, designated pulmonary fibrosis-regulatory lncRNA (PFRL), with unknown functions and found that its levels were increased in fibrotic lung tissues of mice and pulmonary fibroblasts exposed to transforming growth factor (TGF)-β1. Furthermore, we found that enforced expression of PFRL induced fibroblast activation and collagen deposition, which could be mitigated by the overexpression of microRNA (miR)-26a. By contrast, the inhibition of PFRL could markedly alleviate the TGF-β1-induced upregulation of fibrotic markers and attenuate fibroblast proliferation and differentiation by regulating miR-26a. Meanwhile, our study confirmed that PFRL inhibited the expression and activity of miR-26a, which has been identified as an antifibrotic miRNA in our previous study. Interestingly, our molecular study further confirmed that Smad2 transcriptionally inhibits the expression of miR-26a and that the miR-26a/Smad2 feedback loop mediates the profibrotic effects of PFRL in lung fibrosis. More importantly, knockdown of PFRL ablated bleomycin-induced pulmonary fibrosis in vivo. Taken together, our findings indicate that lncRNA PFRL contributes to the progression of lung fibrosis by modulating the reciprocal repression between miR-26a and Smad2 and that this lncRNA may be a therapeutic target for IPF.


Reproduction ◽  
2009 ◽  
Vol 138 (1) ◽  
pp. 95-105 ◽  
Author(s):  
Maud Vallée ◽  
Isabelle Dufort ◽  
Stéphanie Desrosiers ◽  
Aurélie Labbe ◽  
Catherine Gravel ◽  
...  

Gene expression profiling is proving to be a powerful approach for the identification of molecular mechanisms underlying complex cellular functions such as the dynamic early embryonic development. The objective of this study was to perform a transcript abundance profiling analysis of bovine early embryonic development in vivo using a bovine developmental array. The molecular description of the first week of life at the mRNA level is particularly challenging when considering the important fluctuations in RNA content that occur between developmental stages. Accounting for the different intrinsic RNA content between developmental stages was achieved by restricting the reaction time during the global amplification steps and by using spiked controls and reference samples. Analysis based on intensity values revealed that most of the transcripts on the array were present at some point during in vivo bovine early embryonic development, while the varying number of genes detected in each developmental stage confirmed the dynamic profile of gene expression occurring during embryonic development. Pair-wise comparison of gene expression showed a marked difference between oocytes and blastocysts profiles, and principal component analysis revealed that the majority of the transcripts could be regrouped into three main clusters representing distinct RNA abundance profiles. Overall, these data provide a detailed temporal profile of the abundance of mRNAs revealing the richness of signaling processes in early mammalian development. Results presented here provide better knowledge of bovine in vivo embryonic development and contribute to the progression of our current knowledge regarding the first week of life in mammals.


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