scholarly journals Role of chaperone-mediated autophagy in the pathophysiology including pulmonary disorders

2021 ◽  
Vol 41 (1) ◽  
Author(s):  
Yusuke Hosaka ◽  
Jun Araya ◽  
Yu Fujita ◽  
Kazuyoshi Kuwano

AbstractAutophagy is a highly conserved mechanism of delivering cytoplasmic components for lysosomal degradation. Among the three major autophagic pathways, chaperone-mediated autophagy (CMA) is primarily characterized by its selective nature of protein degradation, which is mediated by heat shock cognate 71 kDa protein (HSC70: also known as HSPA8) recognition of the KFERQ peptide motif in target proteins. Lysosome-associated membrane protein type 2A (LAMP2A) is responsible for substrate binding and internalization to lysosomes, and thus, the lysosomal expression level of LAMP2A is a rate-limiting factor for CMA. Recent advances have uncovered not only physiological but also pathological role of CMA in multiple organs, including neurodegenerative disorders, kidney diseases, liver diseases, heart diseases, and cancers through the accumulation of unwanted proteins or increased degradation of target proteins with concomitant metabolic alterations resulting from CMA malfunction. With respect to pulmonary disorders, the involvement of CMA has been demonstrated in lung cancer and chronic obstructive pulmonary disease (COPD) pathogenesis through regulating apoptosis. Further understanding of CMA machinery may shed light on the molecular mechanisms of refractory disorders and lead to novel treatment modalities through CMA modulation.

2020 ◽  
Vol 21 (18) ◽  
pp. 6686
Author(s):  
Yu Ah Hong ◽  
Ji Eun Kim ◽  
Minjee Jo ◽  
Gang-Jee Ko

Sirtuins (SIRTs) are class III histone deacetylases (HDACs) that play important roles in aging and a wide range of cellular functions. Sirtuins are crucial to numerous biological processes, including proliferation, DNA repair, mitochondrial energy homeostasis, and antioxidant activity. Mammals have seven different sirtuins, SIRT1–7, and the diverse biological functions of each sirtuin are due to differences in subcellular localization, expression profiles, and cellular substrates. In this review, we summarize research advances into the role of sirtuins in the pathogenesis of various kidney diseases including acute kidney injury, diabetic kidney disease, renal fibrosis, and kidney aging along with the possible underlying molecular mechanisms. The available evidence indicates that sirtuins have great potential as novel therapeutic targets for the prevention and treatment of kidney diseases.


2014 ◽  
Vol 306 (7) ◽  
pp. L591-L603 ◽  
Author(s):  
Rustin R. Lovewell ◽  
Yash R. Patankar ◽  
Brent Berwin

Pseudomonas aeruginosa is an opportunistic bacterial pathogen responsible for a high incidence of acute and chronic pulmonary infection. These infections are particularly prevalent in patients with chronic obstructive pulmonary disease and cystic fibrosis: much of the morbidity and pathophysiology associated with these diseases is due to a hypersusceptibility to bacterial infection. Innate immunity, primarily through inflammatory cytokine production, cellular recruitment, and phagocytic clearance by neutrophils and macrophages, is the key to endogenous control of P. aeruginosa infection. In this review, we highlight recent advances toward understanding the innate immune response to P. aeruginosa, with a focus on the role of phagocytes in control of P. aeruginosa infection. Specifically, we summarize the cellular and molecular mechanisms of phagocytic recognition and uptake of P. aeruginosa, and how current animal models of P. aeruginosa infection reflect clinical observations in the context of phagocytic clearance of the bacteria. Several notable phenotypic changes to the bacteria are consistently observed during chronic pulmonary infections, including changes to mucoidy and flagellar motility, that likely enable or reflect their ability to persist. These traits are likewise examined in the context of how the bacteria avoid phagocytic clearance, inflammation, and sterilizing immunity.


Author(s):  
Татьяна Виткина ◽  
Tatyana Vitkina ◽  
К Сидлецкая ◽  
K Sidleckaya

The review focuses on the role of interleukin-6 (IL-6) signaling in the development of a systemic inflammatory process in chronic obstructive pulmonary disease (COPD). In most researches the attention is paid to local inflammation in COPD. However, it is known that the pathology is characterized by a systemic inflammatory process, which is manifested in the increased levels of proinflammatory mediators in blood flow, and the study of the molecular mechanisms of its development is very important for the therapy of the disease. One of the key mediators of systemic inflammation is cytokine IL-6 which has pro- and antiinflammatory properties. Its effect on the cells is determined by the type of signaling. Nowadays three types of IL-6 signaling are identified: transsignaling, classical and cluster signaling. The review presents the known pathophysiological mechanisms of the development of systemic inflammation in COPD involving IL-6. As a proinflammatory cytokine, IL-6 performs the following functions: transmission of a signal on lung tissue damage, initiation of leukocyte migration into the inflammation site, inhibition of T-cell apoptosis into the inflammation site, influence on T helper differentiation, participation in pathophysiological reactions of development of emphysema and fibrosis. The significance of IL-6 transsignaling for the development of inflammation in COPD has been confirmed by many studies, while there are practically no works devoted to the study of classical IL-6 signaling in COPD. The data presented in the review indicate the need for further study of the role of different types of IL-6 signaling, especially classical signaling, in the regulation of systemic inflammation in COPD.


Thorax ◽  
2021 ◽  
pp. thoraxjnl-2020-214712
Author(s):  
Qiong Huang ◽  
Chen Duo Li ◽  
Yi Ran Yang ◽  
Xiao Feng Qin ◽  
Jing Jing Wang ◽  
...  

BackgroundEfficient therapy and potential prophylaxis are confounded by current ignorance of the pathogenesis of airway remodelling and blockade in COPD.ObjectiveTo explore the role of the IL-33/ST2 axis in cigarette smoke (CS) exposure-induced airways remodelling.MethodsC57BL/6, BALB/c and IL-1RL1-/- mice exposed to CS were used to establish an animal surrogate of COPD (air-exposed=5~8, CS-exposed=6~12). Hallmarks of remodelling were measured in mice. Cigarette smoke extract (CSE)-induced proliferation and protein production in vitro by fibroblasts in the presence of anti-interleukin-33 (anti-IL-33) or hST2 antibodies were measured. Expression of IL-33 and ST2 and other remodelling hallmarks were measured, respectively, in bronchoalveolar lavage fluid (BALF) (controls=20, COPD=20), serum (controls=59, COPD=90) and lung tissue sections (controls=11, COPD=7) from patients with COPD and controls.ResultsWild-type mice exposed to CS elevated expression of hallmarks of tissue remodelling in the lungs and also in the heart, spleen and kidneys, which were significantly abrogated in the IL-1RL1-/- mice. Fibroblasts exposed to CSE, compared with control, exhibited early cellular translocation of IL-33, accompanied by proliferation and elevated protein synthesis, all inhabitable by blockade of IL-33/ST2 signalling. Expression of IL-33 and ST2 and hallmarks of tissue remodelling were significantly and proportionally elevated in BALF, serum and tissue samples from patients with COPD.ConclusionsExposure to CS induces remodelling changes in multiple organs. The data support the hypothesis that CS-induced lung collagen deposition is at least partly a result of CS-induced IL-33 translocation and release from local fibroblasts.


2018 ◽  
Vol 50 (3) ◽  
pp. 1029-1040 ◽  
Author(s):  
Ning Zhang ◽  
Xin Meng ◽  
Lijun Mei ◽  
Jian Hu ◽  
Chedong Zhao ◽  
...  

Background/Aims: Long non-coding RNAs (lncRNAs) are theorized to play key roles in the development of heart diseases. However, the role of lncRNAs in cardiomyocyte apoptosis is largely unknown. The present study examined the role of lncRNA SNHG1 in the human cardiomyocytes (HCMs) apoptosis and explored the underlying molecular mechanisms. Methods: SNHG1, miR-195 and mRNA expression was detected by qRT-PCR; protein level was determined by western blot; cell viability was detected by MTT assay; cell apoptosis was evaluated by flow cytometry and caspase-3 activity assay; the interaction between SNHG1 and miR195 was examined by using luciferase reporter assay. Results: Hydrogen peroxide (H2O2) treatment significantly suppressed cell viability and increased cell apoptotic rate and caspase-3 activity in HCMs. Overexpression of SNHG1 attenuated the effects of H2O2 on HCMs viability and apoptosis; while SNHG1 exerted the opposite effects. SNHG1 was found to sponge miR-195 and suppress the expression of miR-195 in HCMs. Overexpression of miR-195 suppressed cell viability and induced apoptosis in HCMs, and miR-195 was found to negatively regulate the expression of BCL-2 like protein 2 (BCL2L2) via targeting its 3’ untranslated region. Overexpression of BCL2L2 partially reversed the effects of miR-195 overexpression on cell viability and cell apoptosis of HCMs. MiR-195 overexpression or BCL2L2 knockdown attenuated the effects of SNHG1 overexpression on cell viability, cell apoptosis and protein levels of cleaved caspase-3, cleaved caspase-9 and Bax in H2O2-treated HCMs. Conclusion: Our results suggest a novel SNHG1/miR-195/BCL2L2 axis in the regulation of cardiomyocyte apoptosis. Modulation of SNHG1 may represent a novel strategy to treat cardiomyocyte apoptosis-related heart diseases.


2021 ◽  
Vol 11 (2) ◽  
pp. 736
Author(s):  
Giusi Alberti ◽  
Letizia Paladino ◽  
Alessandra Maria Vitale ◽  
Celeste Caruso Bavisotto ◽  
Everly Conway de Macario ◽  
...  

Neuroinflammation is implicated in central nervous system (CNS) diseases, but the molecular mechanisms involved are poorly understood. Progress may be accelerated by developing a comprehensive view of the pathogenesis of CNS disorders, including the immune and the chaperone systems (IS and CS). The latter consists of the molecular chaperones; cochaperones; and chaperone cofactors, interactors, and receptors of an organism and its main collaborators in maintaining protein homeostasis (canonical function) are the ubiquitin–proteasome system and chaperone-mediated autophagy. The CS has also noncanonical functions, for instance, modulation of the IS with induction of proinflammatory cytokines. This deserves investigation because it may be at the core of neuroinflammation, and elucidation of its mechanism will open roads toward developing efficacious treatments centered on molecular chaperones (i.e., chaperonotherapy). Here, we discuss information available on the role of three members of the CS—heat shock protein (Hsp)60, Hsp70, and Hsp90—in IS modulation and neuroinflammation. These three chaperones occur intra- and extracellularly, with the latter being the most likely involved in neuroinflammation because they can interact with the IS. We discuss some of the interactions, their consequences, and the molecules involved but many aspects are still incompletely elucidated, and we hope that this review will encourage research based on the data presented to pave the way for the development of chaperonotherapy. This may consist of blocking a chaperone that promotes destructive neuroinflammation or replacing or boosting a defective chaperone with cytoprotective activity against neurodegeneration.


2021 ◽  
Vol 12 ◽  
Author(s):  
Lee K. Page ◽  
Karl J. Staples ◽  
C. Mirella Spalluto ◽  
Alastair Watson ◽  
Tom M. A. Wilkinson

Under normal physiological conditions, the lung remains an oxygen rich environment. However, prominent regions of hypoxia are a common feature of infected and inflamed tissues and many chronic inflammatory respiratory diseases are associated with mucosal and systemic hypoxia. The airway epithelium represents a key interface with the external environment and is the first line of defense against potentially harmful agents including respiratory pathogens. The protective arsenal of the airway epithelium is provided in the form of physical barriers, and the production of an array of antimicrobial host defense molecules, proinflammatory cytokines and chemokines, in response to activation by receptors. Dysregulation of the airway epithelial innate immune response is associated with a compromised immunity and chronic inflammation of the lung. An increasing body of evidence indicates a distinct role for hypoxia in the dysfunction of the airway epithelium and in the responses of both innate immunity and of respiratory pathogens. Here we review the current evidence around the role of tissue hypoxia in modulating the host-pathogen interaction at the airway epithelium. Furthermore, we highlight the work needed to delineate the role of tissue hypoxia in the pathophysiology of chronic inflammatory lung diseases such as asthma, cystic fibrosis, and chronic obstructive pulmonary disease in addition to novel respiratory diseases such as COVID-19. Elucidating the molecular mechanisms underlying the epithelial-pathogen interactions in the setting of hypoxia will enable better understanding of persistent infections and complex disease processes in chronic inflammatory lung diseases and may aid the identification of novel therapeutic targets and strategies.


2001 ◽  
Vol 14 (2) ◽  
pp. 336-363 ◽  
Author(s):  
Sanjay Sethi ◽  
Timothy F. Murphy

SUMMARY Chronic obstructive pulmonary disease (COPD) is the fourth leading cause of death in the United States. The precise role of bacterial infection in the course and pathogenesis of COPD has been a source of controversy for decades. Chronic bacterial colonization of the lower airways contributes to airway inflammation; more research is needed to test the hypothesis that this bacterial colonization accelerates the progressive decline in lung function seen in COPD (the vicious circle hypothesis). The course of COPD is characterized by intermittent exacerbations of the disease. Studies of samples obtained by bronchoscopy with the protected specimen brush, analysis of the human immune response with appropriate immunoassays, and antibiotic trials reveal that approximately half of exacerbations are caused by bacteria. Nontypeable Haemophilus influenzae, Moraxella catarrhalis, and Streptococcus pneumoniae are the most common causes of exacerbations, while Chlamydia pneumoniae causes a small proportion. The role of Haemophilus parainfluenzae and gram-negative bacilli remains to be established. Recent progress in studies of the molecular mechanisms of pathogenesis of infection in the human respiratory tract and in vaccine development guided by such studies promises to lead to novel ways to treat and prevent bacterial infections in COPD.


2020 ◽  
Vol 4 (Supplement_2) ◽  
pp. 454-454
Author(s):  
Dexter Puckett ◽  
Mohammed Alquraishi ◽  
Samah Chahed ◽  
Dina Alani ◽  
Victoria Frankel ◽  
...  

Abstract Objectives The prevalence of obesity and its comorbidities has sparked a worldwide concern to address rates of adipose tissue accrual. Recent studies have demonstrated a novel role of Zyflamend, a natural herbal extract, in regulating lipid metabolism in several cancer cell lines through the activation of the AMPK signaling pathway. Yet, the role of Zyflamend in adipogenic differentiation and lipid metabolism remains largely unexplored. The objective of this study is to investigate the effects of Zyflamend on white 3T3-MBX pre-adipocyte differentiation and elucidate the molecular mechanisms. Methods 3T3-MBX pre-adipocytes were treated with Zyflamend, and the expression of various key adipogenic and lipolytic regulators was examined. We also investigated the effects of Zyflamend on pre-adipocyte survival, proliferation, and cell cycle. Results Zyflamend treatment altered cell cycle progression, attenuated proliferation, and increased cell death of 3T3-MBX pre-adipocytes. In addition, treatment with Zyflamend inhibited lipid accumulation during the differentiation of 3T3-MBX cells, consistent with decreased expression of lipogenic genes and increased lipolysis. Mechanistically, Zyflamend-induced alterations in adipogenesis were mediated, at least in part, through the activation of AMPK, PKA, and JNK. Inhibition of AMPK partially reversed Zyflamend-induced inhibition of differentiation, whereas the inhibition of either JNK or PKA fully restored adipocyte differentiation and decreased lipolysis. Conclusions Taken together, the present study demonstrates that Zyflamend, as a novel anti-adipogenic bioactive mix, inhibits adipocyte differentiation through the activation of PKA and JNK pathways.Our findings suggest that Zyflamend supplementation might help in developing novel anti-obesity therapeutic strategies. Funding Sources This work was supported by the National Institute of Diabetes and Digestive and Kidney Diseases (R00DK100736) to A.B.


2018 ◽  
Vol 315 (6) ◽  
pp. F1759-F1768 ◽  
Author(s):  
Hui Fang ◽  
Mokan Deng ◽  
Linlin Zhang ◽  
Aihua Lu ◽  
Jiahui Su ◽  
...  

Proteinuria is not only a common feature of chronic kidney diseases (CKD) but also an independent risk factor promoting CKD progression to end-stage renal failure. However, the underlying molecular mechanisms for protein overload-induced renal injury remain elusive. The present study examined the role of (pro)renin receptor (PRR) in pathogenesis of albumin overload (AO)-induced nephropathy and activation of the intrarenal renin-angiotensin system (RAS) in rats. Wistar rats underwent unilateral nephrectomy and were treated for 7 wk with vehicle, bovine serum albumin (5 g·kg−1·day−1via a single ip injection), alone or in conjunction with the PRR decoy inhibitor PRO20 (500 μg·kg−1·day−1via 3 sc injections). The AO rat model exhibited severe proteinuria, tubular necrosis, and interstitial fibrosis, oxidative stress, and inflammation, accompanied by elevated urinary N-acetyl-β-d-glucosaminidase activity and urinary β2-microglobulin secretion, all of which were significantly attenuated by PRO20. Urinary and renal levels of renin, angiotensinogen, and ANG II were elevated by AO and suppressed by PRO20, contrasting to largely unaltered plasma levels of the RAS parameters. The AO model also showed increased renal expression of full-length PRR and soluble PRR (sPRR) and urinary excretion of sPRR. Taken together, we conclude that PRR antagonism with PRO20 alleviates AO-induced nephropathy via inhibition of intrarenal RAS.


Sign in / Sign up

Export Citation Format

Share Document