Downregulation of Hemeoxygenase-1 and Altered Cellular Homeostasis in Cystic Fibrosis

Pneumologie ◽  
2014 ◽  
Vol 68 (06) ◽  
Author(s):  
SP Chillappagari ◽  
S Venkatesan ◽  
V Garapati ◽  
P Mahavadi ◽  
A Munder ◽  
...  
Cells ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 1952 ◽  
Author(s):  
Garrett Pehote ◽  
Neeraj Vij

The preservation of cellular homeostasis requires the synthesis of new proteins (proteostasis) and organelles, and the effective removal of misfolded or impaired proteins and cellular debris. This cellular homeostasis involves two key proteostasis mechanisms, the ubiquitin proteasome system and the autophagy–lysosome pathway. These catabolic pathways have been known to be involved in respiratory exacerbations and the pathogenesis of various lung diseases, such as chronic obstructive pulmonary disease (COPD), cystic fibrosis (CF), idiopathic pulmonary fibrosis (IPF), acute lung injury (ALI), acute respiratory distress syndrome (ARDS), and coronavirus disease-2019 (COVID-19). Briefly, proteostasis and autophagy processes are known to decline over time with age, cigarette or biomass smoke exposure, and/or influenced by underlying genetic factors, resulting in the accumulation of misfolded proteins and cellular debris, elevating apoptosis and cellular senescence, and initiating the pathogenesis of acute or chronic lung disease. Moreover, autophagic dysfunction results in an impaired microbial clearance, post-bacterial and/or viral infection(s) which contribute to the initiation of acute and recurrent respiratory exacerbations as well as the progression of chronic obstructive and restrictive lung diseases. In addition, the autophagic dysfunction-mediated cystic fibrosis transmembrane conductance regulator (CFTR) immune response impairment further exacerbates the lung disease. Recent studies demonstrate the therapeutic potential of novel autophagy augmentation strategies, in alleviating the pathogenesis of chronic obstructive or restrictive lung diseases and exacerbations such as those commonly seen in COPD, CF, ALI/ARDS and COVID-19.


JAMA ◽  
1966 ◽  
Vol 195 (12) ◽  
pp. 993-1000 ◽  
Author(s):  
R. J. Grand
Keyword(s):  

Author(s):  
J. V. Briggman ◽  
J. Bigelow ◽  
H. Bank ◽  
S. S. Spicer

The prevalence of strands shown by freeze-fracture in the zonula occludens of junctional complexes is thought to correspond closely with the transepi-thelial electrical resistance and with the tightness of the junction and its obstruction to paracellular flow.1 The complexity of the network of junc¬tional complex strands does not appear invariably related to the degree of tightness of the junction, however, as rabbit ileal junctions have a complex network of strands and are permeable to lanthanum. In human eccrine sweat glands the extent of paracellular relative to transcellular flow remains unknown, both for secretion of the isotonic precursor fluid by the coil and for resorption of a hypertonic solution by the duct. The studies reported here undertook, therefore, to determine with the freeze-fracture technique the complexity of the network of ridges in the junctional complexes between cells in the secretory coil and the sweat ducts. Glands from a patient with cystic fibrosis were also examined because an alteration in junctional strands could underlie the decreased Na+ resorption by sweat ducts in this disease. Freeze-fracture replicas were prepared by standard procedures on isolated coil and duct segments of human sweat glands. Junctional complexes between clear cells, between dark cells and between clear and dark cells on the main lumen, and between clear cells on intercellular canaliculi of the coil con¬tained abundant anastomosing closely spaced strands averaging 6.4 + 0.7 (mean + SE) and 9.0 +0.5 (Fig. 1) per complex, respectively. Thus, the junctions in the intercellular canaliculi of the coil appeared comparable in complexity to those of tight epithlia. Occasional junctions exhibited, in addition, 2 to 5 widely spaced anastomosing strands in a very close network basal to the compact network. The fewer junctional complexes observed thus far between the superficial duct cells consisted on the average of 6 strands arranged in a close network and 1 to 4 underlying strands that lay widely separated from one another (Fig. 2). The duct epitelium would, thus, be judged slightly more "leaky" than the coil. Infrequent junctional complexes observed to date in the secretory coil segment of a cystic fibrosis specimen disclosed rela¬tively few closely crowded strands.


2020 ◽  
Vol 48 (2) ◽  
pp. 631-644 ◽  
Author(s):  
Rajdeep Das ◽  
Oishee Chakrabarti

The cellular mitochondrial population undergoes repeated cycles of fission and fusion to maintain its integrity, as well as overall cellular homeostasis. While equilibrium usually exists between the fission–fusion dynamics, their rates are influenced by organellar and cellular metabolic and pathogenic conditions. Under conditions of cellular stress, there is a disruption of this fission and fusion balance and mitochondria undergo either increased fusion, forming a hyperfused meshwork or excessive fission to counteract stress and remove damaged mitochondria via mitophagy. While some previous reports suggest that hyperfusion is initiated to ameliorate cellular stress, recent studies show its negative impact on cellular health in disease conditions. The exact mechanism of mitochondrial hyperfusion and its role in maintaining cellular health and homeostasis, however, remain unclear. In this review, we aim to highlight the different aspects of mitochondrial hyperfusion in either promoting or mitigating stress and also its role in immunity and diseases.


1999 ◽  
Vol 37 (4) ◽  
pp. 291-293 ◽  
Author(s):  
B. Cimon ◽  
J. Carrere ◽  
J. P. Chazalette ◽  
J. F. Vinatier ◽  
D. Chabasse ◽  
...  

2001 ◽  
Vol 120 (5) ◽  
pp. A137-A137
Author(s):  
D CHILDS ◽  
D CROMBIE ◽  
V PRATHA ◽  
Z SELLERS ◽  
D HOGAN ◽  
...  

2005 ◽  
Vol 39 (8) ◽  
pp. 43
Author(s):  
DAMIAN MCNAMARA
Keyword(s):  

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