scholarly journals Beclin-1–Dependent Autophagy Improves Outcomes of Pneumonia-Induced Sepsis

Author(s):  
Azadeh Nikouee ◽  
Matthew Kim ◽  
Xiangzhong Ding ◽  
Yuxiao Sun ◽  
Qun S. Zang

ObjectiveWe previously demonstrated that promoting Beclin-1–dependent autophagy is cardiac protective during endotoxemia shock, suggesting that autophagy-based approaches may become a promising therapeutic strategy for sepsis. In this study, we applied both genetic and pharmacological approaches to evaluate whether Beclin-1 activation improves sepsis outcomes in a model of pneumonia-induced sepsis.MethodsSepsis was induced in mice by Klebsiella pneumoniae infection via intubation, and outcomes of clinical sickness scores, systemic infection, inflammation, survival, and pulmonary pathology were examined. Evaluation of Beclin-1 activation was achieved by comparing strains of C57BL/6J wild type and Becn1F121A that carries a transgenic expression of Beclin-1–active mutant F121A, and by comparing animal groups treated with Beclin-1–activating peptide, Tat-beclin-1 peptide (TB-peptide), or with vehicle control. The status of autophagy in the lung tissue was examined in autophagy reporter mice, CAG-RFP-EGFP-LC3, by fluorescence microscopy.ResultsPulmonary infection by K. pneumoniae produced an insufficient, maladaptive autophagy in the lung. Activation of Beclin-1 by forced expression of active mutant Becn1F121A or by treatment with TB-peptide enhanced autophagy and significantly reduced sickness scores, systemic infection, and circulating and pulmonary cytokine production. Both approaches demonstrated notable benefits in limiting post-infection pathogenesis in the lung, such as decreases in alveolar congestion, hemorrhage, infiltration of inflammatory cells, and alveolar wall thickness.ConclusionData suggest that targeted activation of Beclin-1 alleviates adverse outcomes of pneumonia-induced sepsis, and thus, possess a therapeutic potential.

2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Faris Alrumaihi ◽  
Ahmad Almatroudi ◽  
Khaled S. Allemailem ◽  
Arshad H. Rahmani ◽  
Arif Khan ◽  
...  

Asthma is characterized by the elevated level of Th2 immune responses, oxidative stress, and airway inflammation. Bilsaan, an exudate from the stem of Sambucus nigra, has been traditionally used in the treatment of various ailments in Saudi Arabia. Here, we investigated the therapeutic potential of Bilsaan against ovalbumin- (OVA-) induced allergic asthma in a mouse model. In order to induce allergic asthma, mice were intraperitoneally injected with alum-emulsified-OVA (20 μg/mouse) on days 0, 14, and 21 that is followed by an intranasal OVA exposure from days 22 to 30. During this time, mice were orally administered with Bilsaan at the doses of 5, 10, and 25 mg/kg. The numbers of total and differential inflammatory cells and the levels of Th2 cytokines (IL-4, IL-5, and IL-13) and IgE were determined in bronchoalveolar lavage fluid (BALF). Moreover, the therapeutic effect of Bilsaan was also assessed to analyze the oxidative stress and inflammatory changes in the lung tissues. The results demonstrated that Bilsaan treatment significantly reduced the total and differential inflammatory cell count in the BALF. The BALF from the mice treated with Bilsaan showed significantly lower levels of IL-4, IL-5, IL-13, and IgE. Interestingly, a similar pattern was observed in IL-4, IL-5, and IL-13 secreted by OVA-sensitized splenocytes from the mice of various groups. Bilsaan treatment alleviated the status of oxidative stress by modulating malondialdehyde (MDA), superoxide dismutase (SOD), and catalase levels in the lung. Moreover, Bilsaan treatment reduced the infiltration of inflammatory cells, thickening of alveolar wall, and congestion in the lung tissues. The findings of the present study demonstrated an antiasthmatic effect of Bilsaan through the modulation of Th2 immune responses, inflammation, and the oxidative stress.


2021 ◽  
pp. 1-4
Author(s):  
Anders Björklund

In two recent postmortem studies, Jeffrey Kordower and colleagues report new findings that open up for an interesting discussion on the status of GDNF/NRTN signaling in patients with Parkinson’s disease (PD), adding an interesting perspective on the, admittedly very limited, signs of restorative effects previously seen in GDNF/NRTN-treated patients. Their new findings show that the level of the GDNF signaling receptor Ret is overall reduced by about 65% relative to non-PD controls, and most severely, up to 80%, in nigral neurons containing α-synuclein inclusions, accompanied by impaired signaling downstream of the Ret receptor. Notably, however, the vast majority of the remaining nigral neurons retained a low level of Ret expression, and hence a threshold level of signaling. Further observations made in two patients who had received AAV-NRTN gene therapy 8–10 years earlier suggest the intriguing possibility that NRTN is able to restore Ret expression and upregulate its own signaling pathway. This “wind-up” mechanism, which is likely to depend on an interaction with dopaminergic transcription factor Nurr1, has therapeutic potential and should encourage renewed efforts to turn GDNF/NRTN therapy into success, once the recurring problem of under-dosing is resolved.


Nutrients ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 1143
Author(s):  
Haiyan Xu ◽  
Keizo Hiraishi ◽  
Lin-Hai Kurahara ◽  
Yuko Nakano-Narusawa ◽  
Xiaodong Li ◽  
...  

Chronic inflammation is a risk factor for colorectal cancer, and inflammatory cytokines secreted from inflammatory cells and active oxygen facilitate tumorigenesis. Intestinal bacteria are thought to regulate tumorigenesis. The longer the breastfeeding period, the lower is the risk of inflammatory bowel disease. Here, we investigated preventive effects of the probiotic Lactobacillus rhamnosus M9 (Probio-M9) on colitis-associated tumorigenesis. An inflammatory colorectal tumor model was established using a 6-week-old male C57BL/6NCrSlc mouse, which was intraperitoneally administered with azoxymethane (AOM: 12 mg/kg body weight). On weeks 2 and 4, 2% dextran sulfate sodium (DSS) was administered to mice for 7 days through drinking water. On weeks 8 and 10, Probio-M9 (2 × 109/day) was orally administered for 7 days. Animals were sacrificed at 20 weeks after AOM administration and immunohistochemical staining and Western blotting was performed. The α-diversity of microflora (Shannon index), principal coordinate analysis, and distribution of intestinal bacterium genera and metabolic pathways were compared. The AOM/DSS group showed weight loss, diarrhea, intestinal shortening, increased number of colon tumors, proliferating tumorigenesis, increased inflammation score, fibrosis, increased CD68+, or CD163+ macrophage cells in the subserosal layer of non-tumor areas. Inflammation and tumorigenesis ameliorated after Probio-M9 treatment. Fecal microbial functions were altered by AOM/DSS treatment. Probio-M9 significantly upregulated the fecal microbial diversity and reversed fecal microbial functions. Thus, Probio-M9 could suppress tumor formation in the large intestine by regulating the intestinal environment and ameliorating inflammation, suggesting its therapeutic potential for treatment of inflammation and colitis-associated tumorigenesis.


2016 ◽  
Vol 113 (27) ◽  
pp. 7614-7619 ◽  
Author(s):  
Yu-bing Dai ◽  
Yi-fei Miao ◽  
Wan-fu Wu ◽  
Yu Li ◽  
Francesca D'Errico ◽  
...  

The etiology of peripheral squamous cell lung cancer (PSCCa) remains unknown. Here, we show that this condition spontaneously develops in mice in which the genes for two oxysterol receptors, Liver X Receptor (LXR) α (Nr1h3) and β (Nr1h2), are inactivated. By 1 y of age, most of these mice have to be euthanized because of severe dyspnea. Starting at 3 mo, the lungs of LXRα,βDko mice, but not of LXRα or LXRβ single knockout mice, progressively accumulate foam cells, so that by 1 y, the lungs are covered by a “golden coat.” There is infiltration of inflammatory cells and progressive accumulation of lipid in the alveolar wall, type 2 pneumocytes, and macrophages. By 14 mo, there are three histological lesions: one resembling adenomatous hyperplasia, one squamous metaplasia, and one squamous cell carcinoma characterized by expression of transformation-related protein (p63), sex determining region Y-box 2 (Sox2), cytokeratin 14 (CK14), and cytokeratin 13 (CK13) and absence of thyroid transcription factor 1 (TTF1), and prosurfactant protein C (pro-SPC). RNA sequencing analysis at 12 mo confirmed a massive increase in markers of M1 macrophages and lymphocytes. The data suggest a previously unidentified etiology of PSCCa: cholesterol dysregulation and M1 macrophage-predominant lung inflammation combined with damage to, and aberrant repair of, lung tissue, particularly the peripheral parenchyma. The results raise the possibility that components of the LXR signaling may be useful targets in the treatment of PSCCa.


2021 ◽  
Vol 12 ◽  
Author(s):  
Emilio G. Vozza ◽  
Michelle E. Mulcahy ◽  
Rachel M. McLoughlin

The success of Staphylococcus aureus as a human commensal and an opportunistic pathogen relies on its ability to adapt to several niches within the host. The innate immune response plays a key role in protecting the host against S. aureus infection; however, S. aureus adeptness at evading the innate immune system is indisputably evident. The “Trojan horse” theory has been postulated to describe a mechanism by which S. aureus takes advantage of phagocytes as a survival niche within the host to facilitate dissemination of S. aureus to secondary sites during systemic infection. Several studies have determined that S. aureus can parasitize both professional and non-professional phagocytes by manipulating the host autophagy pathway in order to create an intracellular survival niche. Neutrophils represent a critical cell type in S. aureus infection as demonstrated by the increased risk of infection among patients with congenital neutrophil disorders. However, S. aureus has been repeatedly shown to survive intracellularly within neutrophils with evidence now supporting a pathogenic role of host autophagy. By manipulating this pathway, S. aureus can also alter the apoptotic fate of the neutrophil and potentially skew other important signalling pathways for its own gain. Understanding these critical host-pathogen interactions could lead to the development of new host directed therapeutics for the treatment of S. aureus infection by removing its intracellular niche and restoring host bactericidal functions. This review discusses the current findings surrounding intracellular survival of S. aureus within neutrophils, the pathogenic role autophagy plays in this process and considers the therapeutic potential for targeting this immune evasion mechanism.


2020 ◽  
Author(s):  
Xue-wei Pan ◽  
Li-xuan Xue ◽  
Qian-liu Zhou ◽  
Jia-zhi Zhang ◽  
Yu-jie Dai ◽  
...  

Abstract Background: Sepsis is a severe disorder leading to a clinically critical syndrome of multiple organ dysfunction syndrome. Most patients with sepsis will be associated with acute lung injury (ALI), which is an independent risk factors of organ failure and death in patients with sepsis at the same time. YiQiFuMai Lyophilized Injection (YQFM) is a modern traditional Chinese prescription preparation, which could ameliorate ALI induced by lipopolysaccharide (LPS) or fine particulate matter. The current study aimed to investigate the effect of YQFM on sepsis-induced ALI and the underlying mechanism.Methods: Male C57BL/6J mice were treated with cecal ligation and puncture (CLP) after tail intravenous injected with YQFM (1, 2 and 4 g/kg). The measurements of lung edema, evans blue leakage, myeloperoxidase content, inflammatory cells in bronchoalveolar lavage fluid, histopathological assay and expression of associated proteins were performed at 18 h after CLP.Results: The results illustrated that YQFM inhibited pulmonary edema and inflammatory response, thus ameliorated ALI in sepsis mice. Furthermore, the expression of TLR4 and phosphorylated Src was down-regulated, and the expression of p120-catenin and VE-cadherin was restored by YQFM administration.Conclusion: Our study suggested the therapeutic potential of YQFM on treating sepsis-induced ALI via regulating TLR4/Src/VE-cadherin/p120-catenin signaling pathway.


2020 ◽  
Vol 12 (524) ◽  
pp. eaax6601 ◽  
Author(s):  
Manoj Puthia ◽  
Marta Butrym ◽  
Jitka Petrlova ◽  
Ann-Charlotte Strömdahl ◽  
Madelene Å. Andersson ◽  
...  

There is a clinical need for improved wound treatments that prevent both infection and excessive inflammation. TCP-25, a thrombin-derived peptide, is antibacterial and scavenges pathogen-associated molecular patterns (PAMPs), such as lipopolysaccharide, thereby preventing CD14 interaction and Toll-like receptor dimerization, leading to reduced downstream immune activation. Here, we describe the development of a hydrogel formulation that was functionalized with TCP-25 to target bacteria and associated PAMP-induced inflammation. In vitro studies determined the polymer prerequisites for such TCP-25–mediated dual action, favoring the use of noncharged hydrophilic hydrogels, which enabled peptide conformational changes and LPS binding. The TCP-25–functionalized hydrogels killed Gram-positive Staphylococcus aureus and Gram-negative Pseudomonas aeruginosa bacteria in vitro, as well as in experimental mouse models of subcutaneous infection. The TCP-25 hydrogel also mediated reduction of LPS-induced local inflammatory responses, as demonstrated by analysis of local cytokine production and in vivo bioimaging using nuclear factor κB (NF-κB) reporter mice. In porcine partial thickness wound models, TCP-25 prevented infection with S. aureus and reduced concentrations of proinflammatory cytokines. Proteolytic fragmentation of TCP-25 in vitro yielded a series of bioactive TCP fragments that were identical or similar to those present in wounds in vivo. Together, the results demonstrate the therapeutic potential of TCP-25 hydrogel, a wound treatment based on the body’s peptide defense, for prevention of both bacterial infection and the accompanying inflammation.


2020 ◽  
Vol 9 (18) ◽  
Author(s):  
Michael T. Kleinman ◽  
Rebecca Johnson Arechavala ◽  
David Herman ◽  
Jianru Shi ◽  
Irene Hasen ◽  
...  

Abstract E‐cigarette or vaping product use–associated lung injury was recognized in the United States in the summer of 2019 and is typified by acute respiratory distress, shortness of breath, chest pain, cough, and fever, associated with vaping. It can mimic many of the manifestations of coronavirus disease 2019 (COVID‐19). Some investigators have suggested that E‐cigarette or vaping product use–associated lung injury was due to tetrahydrocannabinol or vitamin E acetate oil mixed with the electronic cigarette liquid. In experimental rodent studies initially designed to study the effect of electronic cigarette use on the cardiovascular system, we observed an E‐cigarette or vaping product use–associated lung injury‐like condition that occurred acutely after use of a nichrome heating element at high power, without the use of tetrahydrocannabinol, vitamin E, or nicotine. Lung lesions included thickening of the alveolar wall with foci of inflammation, red blood cell congestion, obliteration of alveolar spaces, and pneumonitis in some cases; bronchi showed accumulation of fibrin, inflammatory cells, and mucus plugs. Electronic cigarette users should be cautioned about the potential danger of operating electronic cigarette units at high settings; the possibility that certain heating elements may be deleterious; and that E‐cigarette or vaping product use–associated lung injury may not be dependent upon tetrahydrocannabinol, vitamin E, or nicotine.


2016 ◽  
Vol 44 (01) ◽  
pp. 133-147 ◽  
Author(s):  
Chen-Chen Lee ◽  
Yueh-Lun Lee ◽  
Chien-N Wang ◽  
Hsing-Chuan Tsai ◽  
Chun-Lung Chiu ◽  
...  

The root of Polygonum multiflorum (also called He-Shou-Wu in Chinese) is a common herb and medicinal food in Asia used for its anti-aging properties. Our study investigated the therapeutic potential of an extract of the root of Polygonum multiflorum (PME) in allergic asthma by using a mouse model. Feeding of 0.5 and 1 mg/mouse PME inhibited ovalbumin (OVA)-induced allergic asthma symptoms, including airway inflammation, mucus production, and airway hyper-responsiveness (AHR), in a dose-dependent manner. To discern PME’s mechanism of action, we examined the profile and cytokine production of inflammatory cells in bronchial alveolar lavage fluid (BALF). We found that eosinophils, the main inflammatory cell infiltrate in the lung of OVA-immunized mice, significantly decreased after PME treatment. Th2 cytokine levels, including interleukin (IL)-4, IL-5, IL-13, eotaxin, and the proinflammatory cytokine tumor necrosis factor (TNF)-[Formula: see text], decreased in PME-treated mice. Elevated mRNA expression of Th2 transcription factor GATA-3 in the lung tissue was also inhibited after oral feeding of PME in OVA-immunized mice. Thus, we conclude that PME produces anti-asthma activity through the inhibition of Th2 cell activation.


2016 ◽  
Vol 397 (6) ◽  
pp. 485-496 ◽  
Author(s):  
Julie Laval ◽  
Anjali Ralhan ◽  
Dominik Hartl

Abstract Cystic fibrosis (CF) lung disease is characterized by chronic infection and inflammation. Among inflammatory cells, neutrophils represent the major cell population accumulating in the airways of CF patients. While neutrophils provide the first defensive cellular shield against bacterial and fungal pathogens, in chronic disease conditions such as CF these short-lived immune cells release their toxic granule contents that cause tissue remodeling and irreversible structural damage to the host. A variety of human and murine studies have analyzed neutrophils and their products in the context of CF, yet their precise functional role and therapeutic potential remain controversial and incompletely understood. Here, we summarize the current evidence in this field to shed light on the complex and multi-faceted role of neutrophils in CF lung disease.


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