scholarly journals Impairment of the autophagy-lysosomal pathway and activation of pyroptosis in macular corneal dystrophy

2020 ◽  
Vol 6 (1) ◽  
Author(s):  
Tao Zheng ◽  
Chuchu Zhao ◽  
Baowen Zhao ◽  
Hanruo Liu ◽  
Shijian Wang ◽  
...  
Keyword(s):  
Inflammatory Responses ◽  
Periodic Acid ◽  
Corneal Transplantation ◽  
Corneal Stroma ◽  
Keratan Sulfate ◽  
Corneal Dystrophy ◽  
Autophagic Flux ◽  
Periodic Acid Schiff ◽  
Caspase 1 ◽  
Macular Corneal Dystrophy

Abstract Macular corneal dystrophy (MCD) is ascribed to mutations in the carbohydrate sulfotransferase (CHST6) gene affecting keratan sulfate (KS) hydrophilicity and causing non-sulfated KS to precipitate in keratocytes and the corneal stroma. We investigated roles for inflammatory responses in MCD pathogenesis by examining the lysosomal-autophagy pathway and activation of pyroptosis in MCD keratocytes. Normal and lesioned keratocytes were obtained from MCD patients undergoing corneal transplantation. The keratocytes were subjected to gene sequencing, RT-PCR, western blotting, transmission electron microscopy, histological staining, induction and inhibition assays of autophagy and pyroptosis, CCK-8 and LysoTracker Green DND-26 labeling, and flow cytometry. A novel homozygous MCD mutation was identified in a family from Northeast China; the mutation was distinguished by cytoplasmic vacuolation, cell membrane disruption, electron dense deposits, and deposition of a band of Periodic acid-Schiff and Alcian blue-positive material in the keratocytes and stroma layer. KS protein levels were decreased, expression of p62 and LC3-II proteins was enhanced, cathepsin D expression was declined and the LysoTracker Green DND-26 signal was dramatically reduced in MCD keratocytes. Bafilomycin-A1 treatment significantly increased caspase-1 and Pro-IL-1β expression in normal and MCD keratocytes. Nod-like receptors pyrins-3 (NLRP3), caspase-1, Pro-IL-1β, and IL-1β levels were pronouncedly elevated in cells exposed to H2O2. Ac-YVAD-CMK treatment reversed this expression in normal and MCD keratocytes. Suppression of the autophagic degradation of non-sulfated KS by impaired autophagic flux in MCD keratocytes triggers pyroptosis. Amelioration of impaired autophagy and restraint of pyroptosis may, therefore, have therapeutic efficacy in the treatment of MCD.

Effects of matrix metalloproteinase inhibitor on LPS-induced goblet cell metaplasia

2004 ◽  
Vol 287 (1) ◽  
pp. L127-L133 ◽  
Author(s):  
Je Hyeong Kim ◽  
Sung Yong Lee ◽  
Sang Myeon Bak ◽  
In Bum Suh ◽  
Sang Yeub Lee ◽  
...  
Keyword(s):  
Goblet Cell ◽  
Bacterial Infections ◽  
Inflammatory Responses ◽  
Periodic Acid ◽  
Growth Factor Receptor ◽  
Sprague Dawley ◽  
Neutrophilic Infiltration ◽  
Periodic Acid Schiff ◽  
Mucus Hypersecretion ◽  
Egfr Expression

Bacterial infections of the lung are known to induce inflammatory responses, which lead to mucus hypersecretion. Moreover, mucin synthesis in the airways has been reported to be regulated by neutrophilic inflammation-induced epidermal growth factor receptor (EGFR) expression and its activation. Furthermore, matrix metalloproteinases (MMPs), especially MMP-9, have been reported to promote the transmigration of activated neutrophils. In this study, we investigated the associations between lipopolysaccharide (LPS)-induced goblet cell (GC) metaplasia and EGFR expression and the effects of MMP inhibitor (MMPI). Various concentrations of LPS were instilled into the tracheas of pathogen-free Sprague-Dawley rats, and airways were examined at different times after LPS instillation. To examine the role of MMP-9, we treated rats 3 days before LPS instillation and daily thereafter with MMPI. Neutrophilic infiltration, Alcian blue/periodic acid-Schiff (AB/PAS) staining, and immunohistochemical staining for MUC5AC, EGFR, and MMP-9 were performed. The instillation of LPS increased AB/PAS and MUC5AC staining in time- and dose-dependent manners, and treatment with MMPI significantly prevented GC metaplasia. The instillation of LPS into the trachea also induced neutrophilic infiltration and EGFR and MMP-9 expression in the airway epithelium, and MMPI was found to significantly prevent neutrophil recruitment, GC metaplasia, and EGFR and MMP-9 expression. This study demonstrates that the MMP-9 and EGFR cascades are associated with LPS-induced mucus hypersecretion.

scholarly journals Aggravated renal inflammatory responses in TRPV1 gene knockout mice subjected to DOCA-salt hypertension

2009 ◽  
Vol 297 (6) ◽  
pp. F1550-F1559 ◽  
Author(s):  
Youping Wang ◽  
Donna H. Wang
Keyword(s):  
Transient Receptor Potential ◽  
Inflammatory Responses ◽  
Gene Knockout ◽  
Periodic Acid ◽  
Immunosuppressive Drug ◽  
Transient Receptor Potential Vanilloid ◽  
Tubulointerstitial Injury ◽  
Salt Treatment ◽  
Periodic Acid Schiff ◽  
Salt Hypertension

To test the hypothesis that deletion of the transient receptor potential vanilloid type 1 (TRPV1) channel exaggerates hypertension-induced renal inflammatory response, wild-type (WT) or TRPV1-null mutant (TRPV1−/−) mice were subjected to uninephrectomy and deoxycorticosterone acetate (DOCA)-salt treatment for 4 wk. Mean arterial pressure (MAP) determined by radiotelemetry increased in DOCA-salt-treated WT or TRPV1−/− mice, whereas there was no difference in MAP between two strains at the baseline or after DOCA-salt treatment. DOCA-salt treatment increased urinary excretion of albumin and 8-isoprostane in both WT and TRPV1−/− mice, and the increases were greater in magnitude in the latter strain. Periodic acid-Schiff and Mason's trichrome staining showed that kidneys of DOCA-salt-treated TRPV1−/− mice exhibited more severe glomerulosclerosis and tubulointerstitial injury compared with DOCA-salt-treated WT mice. NF-κB assay showed that DOCA-salt treatment increased renal activated NF-κB concentrations in TRPV1−/− mice compared with WT mice. Immunostaining and ELISA assay revealed that DOCA-salt-treated TRPV1−/− mice had enhanced renal infiltration of monocyte/macrophage and lymphocyte, as well as increased renal levels of proinflammatory cytokine (TNF-α, IL-6) and chemokine (MCP-1) compared with DOCA-salt-treated WT mice. Renal ICAM-1 but not VCAM-1 expression was also greater in DOCA-salt-treated TRPV1−/− than WT mice. Dexamethasone (DEXA), an immunosuppressive drug, conveyed a renoprotective effect that was greater in DOCA-salt-treated TRPV1−/− compared with WT mice. These data show that renal inflammation is exacerbated in DOCA-salt hypertension when TRPV1 gene is deleted and that the deterioration is ameliorated by DEXA treatment, indicating that TRPV1 may act as a potential regulator of the inflammatory process to lessen renal injury in DOCA-salt hypertension.

scholarly journals Histochemical properties of cartilage proteoglycans.

1983 ◽  
Vol 31 (1) ◽  
pp. 53-61 ◽  
Author(s):  
E Ippolito ◽  
V A Pedrini ◽  
A Pedrini-Mille
Keyword(s):  
Alcian Blue ◽  
Magnesium Chloride ◽  
Periodic Acid ◽  
Keratan Sulfate ◽  
Periodic Acid Schiff ◽  
Histological Sections ◽  
Connective Tissue Matrix ◽  
Cartilage Proteoglycans ◽  
Tissue Matrix

Proteoglycan interaction with alcian blue at different concentrations of magnesium chloride was studied both in vitro and in histological sections of paraffin-embedded tissues. Our experiments indicate that a) proteoglycans with different contents of chondroitin sulfate and keratan sulfate, prepared under nondegradative conditions, are not distinguishable on the basis of the critical electrolyte concentrations at which staining is abolished; b) the state of aggregation of proteoglycans only very slightly affects the alcian blue affinity of the macromolecules at different concentrations of magnesium chloride; c) the interaction of proteoglycans with other components of the connective tissue matrix is an important factor in determining the strength of binding of alcian blue to the polyanionic macromolecules in histological sections. These factors should be considered in interpreting histochemical data obtained by staining tissue sections with alcian blue at different concentrations of magnesium chloride. Proteoglycans, like glycosaminoglycans, are only weakly periodic acid-Schiff-positive.

scholarly journals Altered Fine Structures of Corneal and Skeletal Keratan Sulfate and Chondroitin/Dermatan Sulfate in Macular Corneal Dystrophy

2001 ◽  
Vol 276 (43) ◽  
pp. 39788-39796 ◽  
Author(s):  
Anna H. Plaas ◽  
Leigh A. West ◽  
Eugene J. A. Thonar ◽  
Zeynel A. Karcioglu ◽  
Clayton J. Smith ◽  
...  
Keyword(s):  
Dermatan Sulfate ◽  
Keratan Sulfate ◽  
Corneal Dystrophy ◽  
Fine Structures ◽  
Macular Corneal Dystrophy

scholarly journals Defective processing of keratan sulfate in macular corneal dystrophy.

1984 ◽  
Vol 259 (22) ◽  
pp. 13751-13757 ◽  
Author(s):  
K Nakazawa ◽  
J R Hassell ◽  
V C Hascall ◽  
L S Lohmander ◽  
D A Newsome ◽  
...  
Keyword(s):  
Keratan Sulfate ◽  
Corneal Dystrophy ◽  
Macular Corneal Dystrophy

scholarly journals Sulfation patterns of keratan sulfate in different macular corneal dystrophy immunophenotypes using three different probes

2008 ◽  
Vol 92 (10) ◽  
pp. 1434-1436 ◽  
Author(s):  
T Saito ◽  
K Nishida ◽  
J Nakayama ◽  
T O Akama ◽  
M N Fukuda ◽  
...  
Keyword(s):  
Keratan Sulfate ◽  
Corneal Dystrophy ◽  
Macular Corneal Dystrophy

scholarly journals Deciphering the mechanoresponsive role of β-catenin in keratoconus epithelium

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Chatterjee Amit ◽  
Prema Padmanabhan ◽  
Janakiraman Narayanan
Keyword(s):  
Corneal Epithelium ◽  
Refractive Surgery ◽  
Structural Changes ◽  
Corneal Transplantation ◽  
Corneal Stroma ◽  
Corneal Dystrophy ◽  
Collagen Crosslinking ◽  
Immunofluorescence Studies ◽  
Ultrastructural Characteristics

AbstractKeratoconus (KC) is a corneal dystrophy characterized by progressive ectasia that leads to severe visual impairment and remains one of the leading indications for corneal transplantation. The etiology is believed to be multifactorial and alterations have been documented in the biomechanical, biochemical and ultrastructural characteristics of the cornea. While the exact site of disease origin is still debated, changes in the corneal epithelium are believed to occur even before the disease is clinically manifested. In this study we investigate the possible role of β-catenin as mechanotransducer in KC corneal epithelium. The sheets of corneal epithelium removed from keratoconic eyes when they underwent collagen crosslinking as a therapeutic procedure were used for this study. The healthy corneal epithelium of patients undergoing Laser Refractive Surgery for the correction of their refractive error, served as controls. Immunoblotting and tissue immunofluorescence studies were performed on KC epithelium to analyse the expression and localization of β-catenin, E-cadherin, ZO1, α-catenin, Cyclin D1, α-actinin, RhoA, and Rac123. Co-immunoprecipitation of β-catenin followed by mass spectrometry of KC epithelium was performed to identify its interacting partners. This was further validated by using epithelial tissues grown on scaffolds of different stiffness. Histology data reported breaks in the Bowman’s layer in KC patients. We hypothesize that these breaks expose the epithelium to the keratoconic corneal stroma, which, is known to have a decreased elastic modulus and that β-catenin acts as a mechanotransducer that induces structural changes such as loss of polarity (Syntaxin3) and barrier function (ZO1) through membrane delocalization. The results of our study strongly suggest that β-catenin could be a putative mechanotransducer in KC epithelium, thus supporting our hypothesis.

scholarly journals Ultrastructural localization of sulfated and unsulfated keratan sulfate in normal and macular corneal dystrophy type I

Glycobiology ◽  
2000 ◽  
Vol 10 (3) ◽  
pp. 305-312 ◽  
Author(s):  
D. Lewis ◽  
Y. Davies ◽  
I. A. Nieduszynski ◽  
F. Lawrence ◽  
A. J. Quantock ◽  
...  
Keyword(s):  
Keratan Sulfate ◽  
Ultrastructural Localization ◽  
Corneal Dystrophy ◽  
Type I ◽  
Macular Corneal Dystrophy
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