scholarly journals Neutrophils use selective autophagy receptor p62/SQSTM1 to target Staphylococcus aureus for degradation in vivo in zebrafish

2019 ◽  
Author(s):  
Josie F Gibson ◽  
Tomasz K Prajsnar ◽  
Christopher J Hill ◽  
Amy K Tooke ◽  
Justyna J Serba ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Bacterial Degradation ◽  
Intracellular Pathogens ◽  
Life Threatening ◽  
Autophagy Pathway ◽  
Cellular Components ◽  
First Time

AbstractAutophagy leads to degradation of cellular components and has an important role in restricting intracellular pathogens. Autophagy receptors, including p62, target invading intracellular pathogens to the autophagy pathway for degradation. Staphylococcus aureus is a significant pathogen of humans and often life-threatening in the immunocompromised. Increasing evidence demonstrates that S. aureus is an intracellular pathogen of immune cells and may use neutrophils as proliferative niche but the intracellular fate of S. aureus following phagocytosis by neutrophils has not previously been analysed in vivo. In vitro, p62 is able to co-localise with intracellular Staphylococcus aureus, but whether p62 is beneficial or detrimental in host defence against S. aureus in vivo had not been determined.Here we use zebrafish to determine the fate and location of S. aureus within neutrophils throughout infection. We show that Lc3 and p62 recruitment to phagocytosed S. aureus is altered depending on the bacterial location within the neutrophil. We also show rapid Lc3 marking of bacterial phagosomes within neutrophils which may be associated with subsequent bacterial degradation. Finally, we find that p62 is important for controlling cytosolic bacteria demonstrating for the first time a key role of p62 in autophagic control of S. aureus in neutrophils.

scholarly journals Cathepsin L plays a key role in SARS-CoV-2 infection in humans and humanized mice and is a promising target for new drug development

2021 ◽  
Vol 6 (1) ◽  
Author(s):  
Miao-Miao Zhao ◽  
Wei-Li Yang ◽  
Fang-Yuan Yang ◽  
Li Zhang ◽  
Wei-Jin Huang ◽  
...  
Keyword(s):  
Drug Development ◽  
Cathepsin L ◽  
Human Cells ◽  
New Drugs ◽  
Disease Course ◽  
Promising Target ◽  
First Time

AbstractTo discover new drugs to combat COVID-19, an understanding of the molecular basis of SARS-CoV-2 infection is urgently needed. Here, for the first time, we report the crucial role of cathepsin L (CTSL) in patients with COVID-19. The circulating level of CTSL was elevated after SARS-CoV-2 infection and was positively correlated with disease course and severity. Correspondingly, SARS-CoV-2 pseudovirus infection increased CTSL expression in human cells in vitro and human ACE2 transgenic mice in vivo, while CTSL overexpression, in turn, enhanced pseudovirus infection in human cells. CTSL functionally cleaved the SARS-CoV-2 spike protein and enhanced virus entry, as evidenced by CTSL overexpression and knockdown in vitro and application of CTSL inhibitor drugs in vivo. Furthermore, amantadine, a licensed anti-influenza drug, significantly inhibited CTSL activity after SARS-CoV-2 pseudovirus infection and prevented infection both in vitro and in vivo. Therefore, CTSL is a promising target for new anti-COVID-19 drug development.

scholarly journals Secreted KIAA1199 promotes the progression of rheumatoid arthritis by mediating hyaluronic acid degradation in an ANXA1-dependent manner

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Wei Zhang ◽  
Guoyu Yin ◽  
Heping Zhao ◽  
Hanzhi Ling ◽  
Zhen Xie ◽  
...  
Keyword(s):  
Rheumatoid Arthritis ◽  
Hyaluronic Acid ◽  
Dependent Manner ◽  
Collagen Induced Arthritis ◽  
Intracellular Degradation ◽  
Main Pathway ◽  
First Time

AbstractIn inflamed joints, enhanced hyaluronic acid (HA) degradation is closely related to the pathogenesis of rheumatoid arthritis (RA). KIAA1199 has been identified as a hyaladherin that mediates the intracellular degradation of HA, but its extracellular function remains unclear. In this study, we found that the serum and synovial levels of secreted KIAA1199 (sKIAA1199) and low-molecular-weight HA (LMW-HA, MW < 100 kDa) in RA patients were significantly increased, and the positive correlation between them was shown for the first time. Of note, treatment with anti-KIAA1199 mAb effectively alleviated the severity of arthritis and reduced serum LMW-HA levels and cytokine secretion in collagen-induced arthritis (CIA) mice. In vitro, sKIAA1199 was shown to mediate exogenous HA degradation by attaching to the cell membrane of RA fibroblast-like synoviosytes (RA FLS). Furthermore, the HA-degrading activity of sKIAA1199 depended largely on its adhesion to the membrane, which was achieved by its G8 domain binding to ANXA1. In vivo, kiaa1199-KO mice exhibited greater resistance to collagen-induced arthritis. Interestingly, this resistance could be partially reversed by intra-articular injection of vectors encoding full-length KIAA1199 instead of G8-deleted KIAA119 mutant, which further confirmed the indispensable role of G8 domain in KIAA1199 involvement in RA pathological processes. Mechanically, the activation of NF-κB by interleukin-6 (IL-6) through PI3K/Akt signaling is suggested to be the main pathway to induce KIAA1199 expression in RA FLS. In conclusion, our study supported the contribution of sKIAA1199 to RA pathogenesis, providing a new therapeutic target for RA by blocking sKIAA1199-mediated HA degradation.

scholarly journals Arginase Activity in Eisenia andrei Coelomocytes: Function in the Earthworm Innate Response

2021 ◽  
Vol 22 (7) ◽  
pp. 3687
Author(s):  
Joanna Homa ◽  
Alina Klosowska ◽  
Magdalena Chadzinska
Keyword(s):  
Immune Response ◽  
Wound Healing ◽  
Arginase Activity ◽  
Eisenia Andrei ◽  
Heavy Metals Ions ◽  
First Time ◽  
Important Marker

Arginase is the manganese metalloenzyme catalyzing the conversion of l-arginine to l-ornithine and urea. In vertebrates, arginase is involved in the immune response, tissue regeneration, and wound healing and is an important marker of alternative anti-inflammatory polarization of macrophages. In invertebrates, data concerning the role of arginase in these processes are very limited. Therefore, in the present study, we focused on the changes in arginase activity in the coelomocytes of Eisenia andrei. We studied the effects of lipopolysaccharide (LPS), hydrogen peroxide (H2O2), heavy metals ions (e.g., Mn2+), parasite infection, wound healing, and short-term fasting (5 days) on arginase activity. For the first time in earthworms, we described arginase activity in the coelomocytes and found that it can be up-regulated upon in vitro stimulation with LPS and H2O2 and in the presence of Mn2+ ions. Moreover, arginase activity was also up-regulated in animals in vivo infected with nematodes or experiencing segment amputation, but not in fasting earthworms. Furthermore, we confirmed that the activity of coelomocyte arginase can be suppressed by l-norvaline. Our studies strongly suggest that similarly to the vertebrates, also in the earthworms, coelomocyte arginase is an important element of the immune response and wound healing processes.

Abstract P283: Parkin Mediates Mitophagy in Cardioprotection

2011 ◽  
Vol 109 (suppl_1) ◽  
Author(s):  
Allen M Andres ◽  
Chengqun Huang ◽  
Eric P Ratliff ◽  
Genaro Hernandez ◽  
Pamela Lee ◽  
...  
Keyword(s):  
Ex Vivo ◽  
Wild Type ◽  
Simulated Ischemia ◽  
Selective Targeting ◽  
Cardioprotective Effects ◽  
Mitochondrial Turnover ◽  
First Time

Autophagy-dependent mitochondrial turnover in response to cellular stress is necessary for maintaining cellular homeostasis. However, the mechanisms that govern the selective targeting of damaged mitochondria are poorly understood. Parkin, an E3 ubiquitin ligase, has been shown to be essential for the selective clearance of damaged mitochondria. Parkin is expressed in the heart, yet its function has not been investigated in the context of cardioprotection. We previously reported that autophagy is required for cardioprotection by ischemic preconditioning (IPC). In the present study, we used simulated ischemia in vitro and IPC in hearts (in vivo and ex vivo) to investigate the role of Parkin in mediating cardioprotection. In HL-1 cells, simulated ischemia induced Parkin translocation to mitochondria and mitochondrial elimination. Mitochondrial loss was blunted in Atg5-deficient cells, revealing the requirement for autophagy in mitochondrial elimination. Consistent with previous reports implicating p62/SQSTM1 in mitophagy, we found that downregulation of p62 attenuated mitophagy and exacerbated cell death in HL-1 cardiomyocytes subjected to simulated ischemia. While wild type mice showed p62 translocation to mitochondria after IPC, Parkin knockout mice exhibited attenuated translocation of p62 to mitochondria. Importantly, ablation of Parkin in mice abolished the cardioprotective effects of IPC. These results reveal for the first time the crucial role of Parkin and mitophagy in cardioprotection.

scholarly journals Fabrication and evaluation of an optimized xenogenic decellularized costal cartilage graft: preclinical studies of a novel biocompatible prosthesis for rhinoplasty

2021 ◽  
Author(s):  
Shuang Lin ◽  
Yuanjia He ◽  
Meihan Tao ◽  
Aijun Wang ◽  
Qiang Ao
Keyword(s):  
Costal Cartilage ◽  
Donor Site ◽  
Rabbit Model ◽  
Operation Time ◽  
Promising Alternative ◽  
Ionic Detergent ◽  
Cellular Components ◽  
First Time

Abstract On account of the poor biocompatibility of synthetic prosthesis, millions of rhinoplasty recipients have been forced to choose autologous costal cartilage as grafts, which suffer from limited availability, morbidity at donor site and prolonged operation time. Here, as a promising alternative to autologous costal cartilage, we developed a novel xenogeneic costal cartilage and explored its feasibility as a rhinoplasty graft for the first time. Adopting an improved decellularization protocol, in which the ionic detergent was substituted by trypsin, the resulting decellularized graft was confirmed to preserve more structural components and better mechanics, and eliminate cellular components effectively. The in vitro and in vivo compatibility experiments demonstrated that the decellularized graft showed excellent biocompatibility and biosecurity. Additionally, the functionality assessment of rhinoplasty was performed in a rabbit model, and the condition of grafts after implantation was comprehensively evaluated. The optimized graft exhibited better capacity to reduce the degradation rate and maintain the morphology, in comparison to the decellularized costal cartilage prepared by conventional protocol. These findings indicate that this optimized graft derived from decellularized xenogeneic costal cartilage provides a new prospective for future investigations of rhinoplasty prosthesis and has great potential for clinical application.

scholarly journals Candida albicans forms biofilms on the vaginal mucosa

Microbiology ◽  
2010 ◽  
Vol 156 (12) ◽  
pp. 3635-3644 ◽  
Author(s):  
M. M. Harriott ◽  
E. A. Lilly ◽  
T. E. Rodriguez ◽  
P. L. Fidel ◽  
M. C. Noverr
Keyword(s):  
Biofilm Formation ◽  
Ex Vivo ◽  
Microscopic Analysis ◽  
Vaginal Mucosa ◽  
First Time ◽  
Established Role ◽  
Type Strains

Current understanding of resistance and susceptibility to vulvovaginal candidiasis challenges existing paradigms of host defence against fungal infection. While abiotic biofilm formation has a clearly established role during systemic Candida infections, it is not known whether C. albicans forms biofilms on the vaginal mucosa and the possible role of biofilms in disease. In vivo and ex vivo murine vaginitis models were employed to examine biofilm formation by scanning electron and confocal microscopy. C. albicans strains included 3153A (lab strain), DAY185 (parental control strain), and mutants defective in morphogenesis and/or biofilm formation in vitro (efg1/efg1 and bcr1/bcr1). Both 3153A and DAY815 formed biofilms on the vaginal mucosa in vivo and ex vivo as indicated by high fungal burden and microscopic analysis demonstrating typical biofilm architecture and presence of extracellular matrix (ECM) co-localized with the presence of fungi. In contrast, efg1/efg1 and bcr1/bcr1 mutant strains exhibited weak or no biofilm formation/ECM production in both models compared to wild-type strains and complemented mutants despite comparable colonization levels. These data show for the first time that C. albicans forms biofilms in vivo on vaginal epithelium, and that in vivo biotic biofilm formation requires regulators of biofilm formation (BCR1) and morphogenesis (EFG1).

scholarly journals Ultrastructural study of degradation of calcium phosphate ceramic by human monocytes and modulation of this activity by HILDA/LIF cytokine.

1996 ◽  
Vol 44 (10) ◽  
pp. 1131-1140 ◽  
Author(s):  
M D Benahmed ◽  
D Heymann ◽  
M Berreur ◽  
M Cottrel ◽  
A Godard ◽  
...  
Keyword(s):  
Calcium Phosphate ◽  
Culture Medium ◽  
Marked Decrease ◽  
Calcium Phosphate Ceramic ◽  
Multinuclear Cells ◽  
Residual Bodies ◽  
First Time

Biodegradation of ceramics in vivo is achieved essentially by monocytes and multinuclear cells (osteoclasts). Monocytes are the key element in this process because they intervene first at the biomaterial implantation site during inflammatory reaction. In this work, in vitro studies were conducted on an ultrastructural scale to determine the specific behavior of these cells with regard to a calcium phosphate (CaP) ceramic. Two types of phagocytosis were observed when cells came into contact with the biomaterial: either CaP crystals were taken up alone and then dissolved in the cytoplasm after disappearance of the phagosome membrane or they were incorporated together with large quantities of culture medium, in which case dissolution occurred after the formation of heterophagosomes. Phagocytosis of CaP coincided with autophagy and the accumulation of residual bodies in the cells. Addition of HILDA/LIF factor to these cultures induced a very marked decrease in phagocytotic activity directed at the capture of CaP crystals and culture medium. Autophagy was reduced, and residual bodies were rare or absent. This study specifies the role of monocytes in CaP biodegradation and demonstrates for the first time that HILDA/LIF has a biological effect on this cell line.

scholarly journals Staphylococcus aureus Infection Induced Oxidative Imbalance in Neutrophils: Possible Protective Role of Nanoconjugated Vancomycin

2012 ◽  
Vol 2012 ◽  
pp. 1-11 ◽  
Author(s):  
Subhankari Prasad Chakraborty ◽  
Panchanan Pramanik ◽  
Somenath Roy
Keyword(s):  
Oxidative Stress ◽  
Staphylococcus Aureus ◽  
Cell Damage ◽  
Treated Group ◽  
Protective Role ◽  
Control Group ◽  
Similar Dose ◽  
Cellular Components

Staphylococcus aureus infection causes oxidative stress in neutrophils. The immune cells use reactive oxygen species (ROS) for carrying out their normal functions while an excess amount of ROS can attack cellular components that lead to cell damage. The present study was aimed to test the protective role of nanoconjugated vancomycin against vancomycin-sensitive Staphylococcus aureus (VSSA) and vancomycin-resistant Staphylococcus aureus (VRSA) infection induced oxidative stress in neutrophils. VSSA- and VRSA-infection were developed in Swiss mice by intraperitoneal injection of 5×106 CFU/mL bacterial solutions. Nanoconjugated vancomycin was treated to VSSA- and VRSA-infected mice at its effective dose for 10 days. Vancomycin was treated to VSSA and VRSA infected mice at similar dose, respectively, for 10 days. The result reveals that in vivo VSSA and VRSA infection significantly increases the level of lipid peroxidation, protein oxidation, oxidized glutathione level, and nitrite generation and decreases the level of reduced glutathione, antioxidant enzyme status, and glutathione-dependent enzymes as compared to control group; which were increased or decreased significantly near to normal in nanoconjugated vancomycin-treated group. These finding suggests the potential use and beneficial protective role of nanoconjugated vancomycin against VSSA and VRSA infection induced oxidative imbalance in neutrophils.

scholarly journals Evolutionarily ancient role of cholecystokinin-type neuropeptide signalling as an inhibitory regulator of feeding-related processes revealed in an echinoderm

2020 ◽  
Author(s):  
Ana B. Tinoco ◽  
Antón Barreiro-Iglesias ◽  
Luis Alfonso Yañez-Guerra ◽  
Jérôme Delroisse ◽  
Ya Zhang ◽  
...  
Keyword(s):  
Body Wall ◽  
Oral Feeding ◽  
Cardiac Stomach ◽  
First Time ◽  
Dose Dependent ◽  
Type Receptor ◽  
Tube Feet

AbstractCholecystokinin (CCK) / sulfakinin (SK)-type neuropeptides regulate feeding and digestion in chordates and protostomes (e.g. insects). Here we characterised CCK/SK-type signalling for the first time in a non-chordate deuterostome - the starfish Asterias rubens (phylum Echinodermata). In this species, two neuropeptides (ArCCK1, ArCCK2) derived from the precursor protein ArCCKP act as ligands for a CCK/SK-type receptor (ArCCKR) and are expressed in the nervous system, digestive system, tube feet and body wall. Furthermore, ArCCK1 and ArCCK2 cause dose-dependent contraction of cardiac stomach, tube foot and body wall apical muscle preparations in vitro and injection of these neuropeptides in vivo triggers cardiac stomach retraction and inhibition of the onset of feeding in A. rubens. Thus, an evolutionarily ancient role of CCK/SK-type neuropeptides as inhibitory regulators of feeding-related processes in the Bilateria has been conserved in the unusual and unique context of the extra-oral feeding behaviour and pentaradial body plan of an echinoderm.

scholarly journals Ancient role of sulfakinin/cholecystokinin-type signalling in inhibitory regulation of feeding processes revealed in an echinoderm

eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Ana B Tinoco ◽  
Antón Barreiro-Iglesias ◽  
Luis Alfonso Yañez Guerra ◽  
Jérôme Delroisse ◽  
Ya Zhang ◽  
...  
Keyword(s):  
Oral Feeding ◽  
Cardiac Stomach ◽  
First Time ◽  
Dose Dependent ◽  
Type Receptor ◽  
Tube Feet ◽  
Inhibitory Regulation

Sulfakinin (SK)/cholecystokinin (CCK)-type neuropeptides regulate feeding and digestion in protostomes (e.g. insects) and chordates. Here, we characterised SK/CCK-type signalling for the first time in a non-chordate deuterostome – the starfish Asterias rubens (phylum Echinodermata). In this species, two neuropeptides (ArSK/CCK1, ArSK/CCK2) derived from the precursor protein ArSK/CCKP act as ligands for an SK/CCK-type receptor (ArSK/CCKR) and these peptides/proteins are expressed in the nervous system, digestive system, tube feet, and body wall. Furthermore, ArSK/CCK1 and ArSK/CCK2 cause dose-dependent contraction of cardiac stomach, tube foot, and apical muscle preparations in vitro, and injection of these neuropeptides in vivo triggers cardiac stomach retraction and inhibition of the onset of feeding in A. rubens. Thus, an evolutionarily ancient role of SK/CCK-type neuropeptides as inhibitory regulators of feeding-related processes in the Bilateria has been conserved in the unusual and unique context of the extra-oral feeding behaviour and pentaradial body plan of an echinoderm.

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