scholarly journals FINE STRUCTURAL IDENTIFICATION OF PEROXISOMES IN MOUSE AND RAT BRONCHIOLAR AND ALVEOLAR EPITHELIUM

1971 ◽  
Vol 19 (6) ◽  
pp. 339-348 ◽  
Author(s):  
PETR PETRIK

Following incubation in Novikoff and Goldfischer's alkaline modification of Graham and Karnovsky's diaminobenzidine (DAB) medium, densely stained bodies were identified in the bronchiolar nonciliated cells (Clara cells) and in type II alveolar cells (great alveolar cells, granular pneumonocytes) in mouse and rat lung. In Clara cells, the electron-dense reaction product was distributed in spherical, single membrane-bound bodies having an average diameter of 0.3-0.4 µ but varying from 0.15-0.65 µ. Neither nucleoids nor crystalline cores were seen inside these structures. These bodies were seen to be often closely associated with rough endoplasmic reticulum cisternae. The electron-lucent vesicles, some of them with a dense core, previously reported as secretion granules, never stained with DAB. The DAB-stained bodies present in type II alveolar cells had a somewhat different morphology. They were often elongated, with an average size of 0.2-0.3 x 0.1 µ but varying between 0.6 and 0.08 µ. The electron density of their staining was the same as in the DAB-positive bodies of Clara cells. Both cell types were studied for acid phosphatase activity; the distribution pattern of the reaction was entirely different from the one reported above. Considering the specificity of this modified reaction and the effect of inhibitors, it is assumed that the DAB-stained bodies present in both Clara and type II alveolar cells—in spite of a slightly atypical aspect in the latter—are peroxisomes.

2019 ◽  
Vol 116 (5) ◽  
pp. 1603-1612 ◽  
Author(s):  
Aaditya Khatri ◽  
Bryan D. Kraft ◽  
Purushothama Rao Tata ◽  
Scott H. Randell ◽  
Claude A. Piantadosi ◽  
...  

Current therapeutic interventions for the treatment of respiratory infections are hampered by the evolution of multidrug resistance in pathogens as well as the lack of effective cellular targets. Despite the identification of multiple region-specific lung progenitor cells, the identity of molecules that might be therapeutically targeted in response to infections to promote activation of progenitor cell types remains elusive. Here, we report that loss of Abl1 specifically in SCGB1A1-expressing cells leads to a significant increase in the proliferation and differentiation of bronchiolar epithelial cells, resulting in dramatic expansion of an SCGB1A1+ airway cell population that coexpresses SPC, a marker for type II alveolar cells that promotes alveolar regeneration following bacterial pneumonia. Furthermore, treatment with an Abl-specific allosteric inhibitor enhanced regeneration of the alveolar epithelium and promoted accelerated recovery of mice following pneumonia. These data reveal a potential actionable target that may be exploited for efficient recovery after pathogen-induced infections.


1998 ◽  
Vol 76 (7-8) ◽  
pp. 721-727 ◽  
Author(s):  
M W Bolt ◽  
W J Racz ◽  
J F Brien ◽  
T M Bray ◽  
T E Massey

Treatment of cardiac dysrhythmias with the iodinated benzofuran derivative amiodarone (AM) is limited by pulmonary toxicity. The susceptibilities of different lung cell types of male Golden Syrian hamsters to AM-induced cytotoxicity were investigated in vitro. Bronchoalveolar lavage and protease digestion to release cells, followed by centrifugal elutriation and density gradient centrifugation, resulted in preparations enriched with alveolar macrophages (98%), alveolar type II cells (75-85%), and nonciliated bronchiolar epithelial (Clara) cells (35-50%). Alveolar type II cell and Clara cell preparations demonstrated decreased viability (by 0.5% trypan blue dye exclusion) when incubated with 50 µM AM for 36 h, and all AM-treated cell preparations demonstrated decreased viability when incubated with 100 or 200 µM AM. Based on a viability index ((viability of AM-treated cells ÷ viability of controls) × 100%), the Clara cell fraction was significantly (p < 0.05) more susceptible than all of the other cell types to 50 µM AM. However, AM cytotoxicity was greatest (p < 0.05) in alveolar macrophages following incubation with 100 or 200 µM AM. There was no difference between any of the enriched cell preparations in the amount of drug accumulated following 24 h of incubation with 50 µM AM, whereas alveolar macrophages accumulated the most drug during incubation with 100 µM AM. Thus, the most susceptible cell type was dependent on AM concentration. AM-induced cytotoxicity in specific cell types may initiate processes leading to inflammation and pulmonary fibrosis.Key words: amiodarone, susceptibility, alveolar macrophage, accumulation.


1993 ◽  
Vol 264 (3) ◽  
pp. L290-L299 ◽  
Author(s):  
S. Hawgood ◽  
D. Latham ◽  
J. Borchelt ◽  
D. Damm ◽  
T. White ◽  
...  

Pulmonary surfactant-associated protein B (SP-B) is a 9-kDa lung-specific protein expressed in alveolar epithelial type II cells and Clara cells. The protein markedly increases the surface activity of phospholipids and is an active component in some surfactants in clinical use. SP-B is produced from a 43-kDa precursor protein by proteolytic cleavage of flanking regions from both the NH2- and COOH-terminal ends of the active protein. In this study we have compared the nature of the posttranslational processing of the SP-B precursor in type II cells and in a heterologous cell line transfected with the SP-B precursor. We found that isolated type II cells produce the 9-kDa form of SP-B from the precursor through a series of intermediates detectable in the cell lysates. In contrast Chinese hamster ovary cells stably transfected with the full-length human SP-B precursor produce the precursor and a 26-kDa intermediate but not the 9-kDa protein. The precursor protein in both cell types is glycosylated with NH2-linked sugars. Our results suggest there is cell specificity in the posttranslational processing of the SP-B precursor.


1998 ◽  
Vol 153 (6) ◽  
pp. 1885-1893 ◽  
Author(s):  
Sekiya Koyama ◽  
Etsuro Sato ◽  
Hiroshi Nomura ◽  
Keishi Kubo ◽  
Masakazu Miura ◽  
...  

2017 ◽  
Vol 37 (10) ◽  
pp. 1203-1218 ◽  
Author(s):  
Miao He ◽  
Takamichi Ichinose ◽  
Seiichi Yoshida ◽  
Tomohiro Ito ◽  
Cuiying He ◽  
...  

2001 ◽  
Vol 194 (12) ◽  
pp. 1835-1846 ◽  
Author(s):  
Barbara A. Small ◽  
Sarah A. Dressel ◽  
Christopher W. Lawrence ◽  
Donald R. Drake ◽  
Mark H. Stoler ◽  
...  

Tissue injury is a common sequela of acute virus infection localized to a specific organ such as the lung. Tissue injury is an immediate consequence of infection with lytic viruses. It can also result from the direct destruction of infected cells by effector CD8+ T lymphocytes and indirectly through the action of the T cell–derived proinflammatory cytokines and recruited inflammatory cells on infected and uninfected tissue. We have examined CD8+ T cell–mediated pulmonary injury in a transgenic model in which adoptively transferred, virus-specific cytotoxic T lymphocytes (CTLs) produce lethal, progressive pulmonary injury in recipient mice expressing the viral target transgene exclusively in the lungs. We have found that over the 4–5 day course of the development of lethal pulmonary injury, the effector CTLs, while necessary for the induction of injury, are present only transiently (24–48 h) in the lung. We provide evidence that the target of the antiviral CD8+ T cells, the transgene expressing type II alveolar cells, are not immediately destroyed by the effector T cells. Rather, after T cell–target interaction, the type II alveolar cells are stimulated to produce the chemokine monocyte chemoattractant protein 1. These results reinforce the concept that, in vivo, the cellular targets of specific CTLs may participate directly in the development of progressive tissue injury by activating in response to interaction with the T cells and producing proinflammatory mediators without sustained in vivo activation of CD8+ T cell effectors.


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