Hyperoxia-induced airway hyperresponsiveness and remodeling in immature rats

1992 ◽  
Vol 262 (3) ◽  
pp. L263-L269 ◽  
Author(s):  
M. B. Hershenson ◽  
S. Aghili ◽  
N. Punjabi ◽  
C. Hernandez ◽  
D. W. Ray ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Airway Hyperresponsiveness ◽  
Muscle Layer ◽  
Airway Responsiveness ◽  
Wall Thickening ◽  
Small Airways ◽  
Smooth Muscle Layer ◽  
Hyperoxic Exposure ◽  
Immature Rats

We exposed 21-day-old rats to either normoxia or hyperoxia (greater than 95% O2) for 8 days and assessed in vivo airway responsiveness to aerosolized and intravenous methacholine (MCh) and airway architecture. Airway responsiveness was determined using a plethysmographic method. Hyperoxia increased airway cholinergic responsiveness, as reflected in a decreased mean ED200 (concentration of MCh required to increase respiratory system resistance by 100%) for both aerosolized MCh [air exposed, 5.94 +/- 2.50 vs. O2 exposed, 0.29 +/- 3.34 (SD) mg/ml, P = 0.0013, unpaired t test] and intravenous MCh (air, 1.40 x 10(-8) vs. O2, 2.45 x 10(-10) mol/kg, P = 0.0002). Airway morphometry was studied in a separate cohort of animals. After fixation by distension with Formalin at 25 cmH2O pressure, each airway cross section was photographed, and airway circumference, epithelial area, and smooth muscle layer area were determined by means of contour tracing using a digitizing pad and microcomputer. For the small airways (circumference less than 1,000 microns), hyperoxia increased both mean epithelial thickness (air, 4.88 +/- 0.53; O2, 8.64 +/- 0.90 microns) and mean smooth muscle layer thickness (air, 2.69 +/- 0.11; O2, 4.79 +/- 0.56 microns; P less than 0.0001 for each). O2 had similar effects on the larger (1,000-3,000 microns) central airways (P less than 0.0001 for both layers). We conclude that chronic hyperoxic exposure induces both airway hyperresponsiveness and airway wall thickening in immature rats.

scholarly journals Distribution of Major Basic Protein on Human Airway following In Vitro Eosinophil Incubation

2010 ◽  
Vol 2010 ◽  
pp. 1-13 ◽  
Author(s):  
Ailing Xue ◽  
John Wang ◽  
Gary C. Sieck ◽  
Mark E. Wylam
Keyword(s):  
Smooth Muscle ◽  
Airway Hyperresponsiveness ◽  
Basic Protein ◽  
Muscle Layer ◽  
Eosinophil Infiltration ◽  
Dependent Manner ◽  
Major Basic Protein ◽  
Human Eosinophil ◽  
Smooth Muscle Layer ◽  
Human Airway

Major basic protein (MBP) released from activated eosinophils may influence airway hyperresponsiveness (AHR) by either direct effects on airway myocytes or by an indirect effect. In this study, human bronchi, freshly isolated human eosinophils, or MBP purified from human eosinophil granules were incubated for studying eosinophil infiltration and MBP localization. Eosinophils immediately adhered to intact human airway as well as to cultured human airway myocytes and epithelium. Following incubation 18–24 h, eosinophils migrated into the airway media, including the smooth muscle layer, but had no specific recruitment to airway neurons. Eosinophils released significant amounts of MBP within the airway media, including areas comprising the smooth muscle layer. Most deposits of MBP were focally discrete and restricted by immunologic detection to a maximum volume of∼300 μm3about the eosinophil. Native MBP applied exogenously was immediately deposited on the surface of the airway, but required at least 1 h to become detected within the media of the airway wall. Tissue MBP infiltration and deposition increased in a time- and concentration-dependent manner. Taken together, these findings suggest that eosinophil-derived cationic proteins may alter airway hyperresponsiveness (AHR) in vivo by an effect that is not limited to the bronchial epithelium.

Adrenomedullin insufficiency increases allergen-induced airway hyperresponsiveness in mice

2007 ◽  
Vol 102 (6) ◽  
pp. 2361-2368 ◽  
Author(s):  
Hiroshi Yamamoto ◽  
Takahide Nagase ◽  
Takayuki Shindo ◽  
Shinji Teramoto ◽  
Tomoko Aoki-Nagase ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Airway Smooth Muscle ◽  
Airway Hyperresponsiveness ◽  
Airway Responsiveness ◽  
Mutant Mice ◽  
Wild Type ◽  
T Helper 1 ◽  
Littermate Control

Adrenomedullin (ADM), a newly identified vasodilating peptide, is reported to be expressed in lungs and have a bronchodilating effect. We hypothesized whether ADM could be involved in the pathogenesis of bronchial asthma. We examined the role of ADM in airway responsiveness using heterozygous ADM-deficient mice ( AM+/−) and their littermate control ( AM+/+). Here, we show that airway responsiveness is enhanced in ADM mutant mice after sensitization and challenge with ovalbumin (OVA). The immunoreactive ADM level in the lung tissue after methacholine challenge was significantly greater in the wild-type mice than that in the mutant. However, the impairment of ADM gene function did not affect immunoglobulins (OVA-specific IgE and IgG1), T helper 1 and 2 cytokines, and leukotrenes. Thus the conventional mechanism of allergen-induced airway responsiveness is not relevant to this model. Furthermore, morphometric analysis revealed that eosinophilia and airway hypersecretion were similarly found in both the OVA-treated ADM mutant mice and the OVA-treated wild-type mice. On the other hand, the area of the airway smooth muscle layer of the OVA-treated mutant mice was significantly greater than that of the OVA-treated wild-type mice. These results suggest that ADM gene disruption may be associated with airway smooth muscle hyperplasia as well as enhanced airway hyperresponsiveness. ADM mutant mice might provide novel insights to study the pathophysiological role of ADM in vivo.

Testosterone exposure in prenatal life disrupts epithelial nuclear morphology, smooth muscle layer pattern, and FGF10 and Shh expression in prostate

Life Sciences ◽  
2021 ◽  
Vol 271 ◽  
pp. 119198
Author(s):  
Luana Araújo Manso ◽  
Barbara Costa Malmann Medeiros ◽  
Giovanna Amaral Rodrigues ◽  
Jordana Gomes Ramos ◽  
Mara Rúbia Marques ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Muscle Layer ◽  
Nuclear Morphology ◽  
Smooth Muscle Layer

scholarly journals Ultrastructural and immunohistochemical localization of plasma membrane Ca2+-ATPase 4 in Ca2+-transporting epithelia

2015 ◽  
Vol 309 (7) ◽  
pp. F604-F616 ◽  
Author(s):  
R. Todd Alexander ◽  
Megan R. Beggs ◽  
Reza Zamani ◽  
Niels Marcussen ◽  
Sebastian Frische ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Plasma Membrane ◽  
Transient Receptor Potential ◽  
Basolateral Membrane ◽  
Receptor Potential ◽  
Human Kidney ◽  
Muscle Layer ◽  
Transient Receptor Potential Vanilloid ◽  
Distal Nephron

Plasma membrane Ca2+-ATPases (PMCAs) participate in epithelial Ca2+ transport and intracellular Ca2+ signaling. The Pmca4 isoform is enriched in distal nephron isolates and decreased in mice lacking the epithelial transient receptor potential vanilloid 5 Ca2+ channel. We therefore hypothesized that Pmca4 plays a significant role in transcellular Ca2+ flux and investigated the localization and regulation of Pmca4 in Ca2+-transporting epithelia. Using antibodies directed specifically against Pmca4, we found it expressed only in the smooth muscle layer of mouse and human intestines, whereas pan-specific Pmca antibodies detected Pmca1 in lateral membranes of enterocytes. In the kidney, Pmca4 showed broad localization to the distal nephron. In the mouse, expression was most abundant in segments coexpressing the epithelial ransient receptor potential vanilloid 5 Ca2+ channel. Significant, albeit lower, expression was also evident in the region encompassing the cortical thick ascending limbs, macula densa, and early distal tubules as well as smooth muscle layers surrounding renal vessels. In the human kidney, a similar pattern of distribution was observed, with the highest PMCA4 expression in Na+-Cl− cotransporter-positive tubules. Electron microscopy demonstrated Pmca4 localization in distal nephron cells at both the basolateral membrane and intracellular perinuclear compartments but not submembranous vesicles, suggesting rapid trafficking to the plasma membrane is unlikely to occur in vivo. Pmca4 expression was not altered by perturbations in Ca2+ balance, pointing to a housekeeping function of the pump in Ca2+-transporting epithelia. In conclusion, Pmca4 shows a divergent expression pattern in Ca2+-transporting epithelia, inferring diverse roles for this isoform not limited to transepithelial Ca2+ transport.

scholarly journals In vivo magnetofection: a novel approach for targeted topical delivery of nucleic acids for rectoanal motility disorders

2018 ◽  
Vol 314 (1) ◽  
pp. G109-G118 ◽  
Author(s):  
Jagmohan Singh ◽  
Ipsita Mohanty ◽  
Satish Rattan
Keyword(s):  
Smooth Muscle ◽  
Gene Delivery ◽  
Nucleic Acids ◽  
Internal Anal Sphincter ◽  
Fecal Pellet ◽  
Muscle Layer ◽  
Motility Disorders ◽  
Circular Smooth Muscle ◽  
Novel Approach

In these studies, we developed a novel approach of in vivo magnetofection for localized delivery of nucleic acids such as micro-RNA-139-5p (miR-139-5p; which is known to target Rho kinase2) to the circular smooth muscle layer of the internal anal sphincter (IAS). The IAS tone is known to play a major role in the rectoanal continence via activation of RhoA-associated kinase (RhoA/ROCK2). These studies established an optimized protocol for efficient gene delivery using an assembly of equal volumes of in vivo PolyMag and miR139-5p or anti-miR-139-5p (100 nM each) injected in the circular smooth muscle layer in the pinpointed areas of the rat perianal region and then incubated for 20 min under magnetic field. Magnetofection efficiency was confirmed and analyzed by confocal microscopy of FITC-tagged siRNA. Using physiological and biochemical approaches, we investigated the effects of miR-139-5p and anti-miR-139-5p on basal intraluminal IAS pressure (IASP), fecal pellet count, IAS tone, agonist-induced contraction, contraction-relaxation kinetics, and RhoA/ROCK2 signaling. Present studies demonstrate that magnetofection-mediated miR-139-5p delivery significantly decreased RhoA/ROCK2, p-MYPT1, and p-MLC20 signaling, leading to decreases in the basal IASP and IAS tone and in rates of contraction and relaxation associated with increase in fecal pellet output. Interestingly, anti-miR-139-5p transfection had opposite effects on these parameters. Collectively, these data demonstrate that magnetofection is a promising novel method of in vivo gene delivery and of nucleotides to the internal anal sphincter for the site-directed and targeted therapy for rectoanal motility disorders. NEW & NOTEWORTHY These studies for the first time demonstrate the success of topical in vivo magnetofection (MF) of nucleic acids using perianal injections. To demonstrate its effectiveness, we used FITC-tagged siRNA via immunofluorescence microcopy and functional and biochemical evidence using miR-139-5p (which is known to target ROCK2). In conclusion, MF allows safe, convenient, efficient, and targeted delivery of oligonucleotides such as siRNAs and microRNAs. These studies have direct therapeutic implications in rectoanal motility disorders especially associated with IAS.

scholarly journals Decreased airway narrowing and smooth muscle contraction in hyperresponsive pigs

2002 ◽  
Vol 93 (4) ◽  
pp. 1296-1300 ◽  
Author(s):  
Debra J. Turner ◽  
Peter B. Noble ◽  
Matthew P. Lucas ◽  
Howard W. Mitchell
Keyword(s):  
Smooth Muscle ◽  
Airway Hyperresponsiveness ◽  
Porcine Model ◽  
Smooth Muscle Contraction ◽  
Airway Wall ◽  
Muscle Contractility ◽  
Smooth Muscle Contractility ◽  
Airway Narrowing

Increased smooth muscle contractility or reduced smooth muscle mechanical loads could account for the excessive airway narrowing and hyperresponsiveness seen in asthma. These mechanisms were investigated by using an allergen-induced porcine model of airway hyperresponsiveness. Airway narrowing to electric field stimulation was measured in isolated bronchial segments, over a range of transmural pressures (0–20 cmH2O). Contractile responses to ACh were measured in bronchial segments and in isolated tracheal smooth muscle strips isolated from control and test (ovalbumin sensitized and challenged) pigs. Test airways narrowed less than controls ( P < 0.0001). Test pigs showed reduced contractility to ACh, both in isolated bronchi ( P < 0.01) and smooth muscle strips ( P < 0.01). Thus isolated airways from pigs exhibiting airway hyperresponsiveness in vivo are hyporesponsive in vitro. The decreased narrowing in bronchi from hyperresponsive pigs may be related to decreased smooth muscle contractility. These data suggest that mechanisms external to the airway wall may be important to the hyperresponsive nature of sensitized lungs.

Origin of Motion in the Human Ureter: Mechanics, Energetics and Kinetics of the Myosin Molecular Motors

2012 ◽  
Vol 79 (2) ◽  
pp. 123-129 ◽  
Author(s):  
Romina Vargiu ◽  
Anna Perinu ◽  
Antonello De Lisa ◽  
Frank Tintrup ◽  
Francesco Manca ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Molecular Motors ◽  
Circular Muscle ◽  
Muscle Layer ◽  
Shortening Velocity ◽  
Smooth Muscle Layer ◽  
Circular Smooth Muscle ◽  
Longitudinal Smooth Muscle ◽  
Human Ureter

Background Ureteral peristalsis is the result of coordinated mechanical motor performance of longitudinal and circular smooth muscle layer of the ureter wall. The main aim of this study was to characterize in smooth muscle of proximal segments of human ureter, the mechanical properties at level of muscle tissue and at level of myosin molecular motors. Methods Ureteral samples were collected from 15 patients, who underwent nephrectomy for renal cancer. Smooth muscle strips longitudinally and circularly oriented from proximal segments of human ureter were used for the in vitro experiments. Mechanical indices including the maximum unloaded shortening velocity (Vmax), and the maximum isometric tension (P0) normalized per cross-sectional area, were determined in vitro determined in electrically evoked contractions of longitudinal and circular smooth muscle strips. Myosin cross-bridge (CB) number per mm2 (Ψ) the elementary force per single CB (Ψ) and kinetic parameters were calculated in muscle strips, using Huxley's equations adapted to nonsarcomeric muscles. Results Longitudinal smooth muscle strips exhibited a significantly (p<0.05) faster Vmax (63%) and a higher P0 (40%), if compared to circular strips. Moreover, longitudinal muscle strips showed a significantly higher unitary force (Ψ) per CB. However, no significant differences were observed in CB number, the attachment (f1) and the detachment (g2) rate constants between longitudinal and circular muscle strips. Conclusions The main result obtained in the present work documents that the mechanical, energetic and unitary forces per CB of longitudinal layer of proximal ureter are better compared to the circular one; these preliminary findings suggested, unlike intestinal smooth muscle, a major role of longitudinal smooth muscle layer in the ureter peristalsis.

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