Protective effects of Cathelicidin against glomerulonephritis through promotion of host defense

2014 ◽  
Vol 2 (3) ◽  
pp. 189-198
Author(s):  
Ajay H. Bahl ◽  
Wanda Lee
Keyword(s):  
Host Defense ◽  
Disulfide Bonds ◽  
Helical Conformation ◽  
Antimicrobial Protein ◽  
Protective Effects ◽  
In Vivo Models ◽  
E Coli ◽  
Risk Of Death

Cathelicidin-related antimicrobial peptides are a family of polypeptides found in lysosomes of macrophages and polymorphonuclear leukocytes (PMNs). Some of these peptides can assume an alpha-helical conformation, others contain one or two disulfide bonds, still others are Pro- and Arg-rich, or Trp-rich. Higher levels of human cathelicidin antimicrobial protein (hCAP18), which are up-regulated by vitamin D, appear to significantly reduce the risk of death from infection in dialysis patients. Using in vitro and in vivo models of kidney infection, we demonstrate key antimicrobial and host immunomodulatory properties of cathelicidins. To directly assess the role of endogenous cathelicidin in the development of glomerulonephritis, WT and mCRAMP KO mice were provided with 5% DSS to induce glomerulonephritis. Some mice groups were administered with E. coli DNA I.P. Our findings showed that mCRAMP KO mice develop more severe glomerulonephritis. These data demonstrate key roles for cathelicidins in host defense against glomerulonephritis and the potential to inform the development of synthetic analogues to modulate specific host-pathogen interactions as novel antimicrobial therapeutics.

scholarly journals Probiotic and Functional Properties of Limosilactobacillus reuteri INIA P572

Nutrients ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 1860
Author(s):  
Patricia Diez-Echave ◽  
Izaskun Martín-Cabrejas ◽  
José Garrido-Mesa ◽  
Susana Langa ◽  
Teresa Vezza ◽  
...  
Keyword(s):  
In Vitro Assays ◽  
Immunomodulatory Activity ◽  
Probiotic Properties ◽  
Protective Effects ◽  
Mice Model ◽  
In Vivo Models ◽  
Food Borne ◽  
Gastrointestinal Conditions

Limosilactobacillus reuteri INIA P572 is a strain able to produce the antimicrobial compound reuterin in dairy products, exhibiting a protective effect against some food-borne pathogens. In this study, we investigated some probiotic properties of this strain such as resistance to gastrointestinal passage or to colonic conditions, reuterin production in a colonic environment, and immunomodulatory activity, using different in vitro and in vivo models. The results showed a high resistance of this strain to gastrointestinal conditions, as well as capacity to grow and produce reuterin in a human colonic model. Although the in vitro assays using the RAW 264.7 macrophage cell line did not demonstrate direct immunomodulatory properties, the in vivo assays using a Dextran Sulphate Sodium (DSS)-induced colitic mice model showed clear immunomodulatory and protective effects of this strain.

scholarly journals Protective effects of carbonic anhydrase inhibition in brain ischaemia in vitro and in vivo models

2021 ◽  
Vol 36 (1) ◽  
pp. 964-976
Author(s):  
Ilaria Dettori ◽  
Irene Fusco ◽  
Irene Bulli ◽  
Lisa Gaviano ◽  
Elisabetta Coppi ◽  
...  
Keyword(s):  
Carbonic Anhydrase ◽  
Protective Effects ◽  
Brain Ischaemia ◽  
In Vivo Models ◽  
Carbonic Anhydrase Inhibition

scholarly journals In Vitro and In Vivo Antibacterial Activities of a Novel Glycylcycline, the 9-t-Butylglycylamido Derivative of Minocycline (GAR-936)

1999 ◽  
Vol 43 (4) ◽  
pp. 738-744 ◽  
Author(s):  
P. J. Petersen ◽  
N. V. Jacobus ◽  
W. J. Weiss ◽  
P. E. Sum ◽  
R. T. Testa
Keyword(s):  
Anaerobic Bacteria ◽  
Tetracycline Resistance ◽  
Protective Effects ◽  
Gram Negative ◽  
E Coli ◽  
Resistance Determinants ◽  
Aerobic And Anaerobic ◽  
Ribosomal Protection

ABSTRACT The 9-t-butylglycylamido derivative of minocycline (TBG-MINO) is a recently synthesized member of a novel group of antibiotics, the glycylcyclines. This new derivative, like the first glycylcyclines, theN,N-dimethylglycylamido derivative of minocycline and 6-demethyl-6-deoxytetracycline, possesses activity against bacterial isolates containing the two major determinants responsible for tetracycline resistance: ribosomal protection and active efflux. The in vitro activities of TBG-MINO and the comparative agents were evaluated against strains with characterized tetracycline resistance as well as a spectrum of recent clinical aerobic and anaerobic gram-positive and gram-negative bacteria. TBG-MINO, with an MIC range of 0.25 to 0.5 μg/ml, showed good activity against strains expressing tet(M) (ribosomal protection), tet(A), tet(B),tet(C), tet(D), and tet(K) (efflux resistance determinants). TBG-MINO exhibited similar activity against methicillin-resistant Staphylococcus aureus (MRSA), penicillin-resistant streptococci, and vancomycin-resistant enterococci (MICs at which 90% of strains are inhibited, ≤0.5 μg/ml). TBG-MINO exhibited activity against a wide diversity of gram-negative aerobic and anaerobic bacteria, most of which were less susceptible to tetracycline and minocycline. The in vivo protective effects of TBG-MINO were examined against acute lethal infections in mice caused by Escherichia coli, S. aureus, andStreptococcus pneumoniae isolates. TBG-MINO, administered intravenously, demonstrated efficacy against infections caused byS. aureus including MRSA strains and strains containingtet(K) or tet(M) resistance determinants (median effective doses [ED50s], 0.79 to 2.3 mg/kg of body weight). TBG-MINO demonstrated efficacy against infections caused by tetracycline-sensitive E. coli strains as well asE. coli strains containing either tet(M) or the efflux determinant tet(A), tet(B), ortet(C) (ED50s, 1.5 to 3.5 mg/kg). Overall, TBG-MINO shows antibacterial activity against a wide spectrum of gram-positive and gram-negative aerobic and anaerobic bacteria including strains resistant to other chemotherapeutic agents. The in vivo protective effects, especially against infections caused by resistant bacteria, corresponded with the in vitro activity of TBG-MINO.

scholarly journals Full Capacity of Recombinant Escherichia coliHeat-Stable Enterotoxin Fusion Proteins for Extracellular Secretion, Antigenicity, Disulfide Bond Formation, and Activity

2000 ◽  
Vol 68 (7) ◽  
pp. 4064-4074 ◽  
Author(s):  
Isabelle Batisson ◽  
Maurice Der Vartanian ◽  
Brigitte Gaillard-Martinie ◽  
Michel Contrepois
Keyword(s):  
Disulfide Bonds ◽  
Secretory Pathway ◽  
Biological Properties ◽  
Leader Peptide ◽  
Dependent Manner ◽  
Reporter Protein ◽  
E Coli ◽  
Heat Stable

ABSTRACT We have successfully used the major subunit ClpG ofEscherichia coli CS31A fimbriae as an antigenic and immunogenic exposure-delivery vector for various heterologous peptides varying in nature and length. However, the ability of ClpG as a carrier to maintain in vitro and in vivo the native biological properties of passenger peptide has not yet been reported. To address this possibility, we genetically fused peptides containing all or part of the E. coli human heat-stable enterotoxin (STh) sequence to the amino or carboxyl ends of ClpG. Using antibodies to the ClpG and STh portions for detecting the hybrids; AMS (4-acetamido-4′-maleimidylstilbene-2,2′-disulfonate), a potent free thiol-trapping reagent, for determining the redox state of STh in the fusion; and the suckling mouse assay for enterotoxicity, we demonstrated that all ClpG-STh proteins were secreted in vitro and in vivo outside the E. coli cells in a heat-stable active oxidized (disulfide-bonded) form. Indeed, in contrast to many earlier studies, blocking the natural NH2 or COOH extremities of STh had, in all cases, no drastic effect on cell release and toxin activity. Only antigenicity of STh C-terminally extended with ClpG was strongly affected in a conformation-dependent manner. These results suggest that the STh activity was not altered by the chimeric structure, and therefore that, like the natural toxin, STh in the fusion had a spatial structure flexible enough to be compatible with secretion and enterotoxicity (folding and STh receptor recognition). Our study also indicates that disulfide bonds were essential for enterotoxicity but not for release, that spontaneous oxidation by molecular oxygen occurred in vitro in the medium, and that the E. coli cell-bound toxin activity in vivo resulted from an effective export processing of hybrids and not cell lysis. None of the ClpG-STh subunits formed hybrid CS31A-STh fimbriae at the cell surface ofE. coli, and a strong decrease in the toxin activity was observed in the absence of CS31A helper proteins. In fact, chimeras translocated across the outer membrane as a free folded monomer once they were guided into the periplasm by the ClpG leader peptide through the CS31A-dependent secretory pathway. In summary, ClpG appears highly attractive as a carrier reporter protein for basic and applied research through the engineering of E. coli for culture supernatant delivery of an active cysteine-containing protein, such as the heat-stable enterotoxin.

scholarly journals DHEA Attenuates Microglial Activation via Induction of JMJD3 in Experimental Subarachnoid Haemorrhage

2019 ◽  
Vol 16 (1) ◽  
Author(s):  
Tao Tao ◽  
Guang-Jie Liu ◽  
Xuan Shi ◽  
Yan Zhou ◽  
Yue Lu ◽  
...  
Keyword(s):  
Subarachnoid Haemorrhage ◽  
Microglial Activation ◽  
Neuronal Damage ◽  
Neuroprotective Effect ◽  
Early Brain Injury ◽  
Protective Effects ◽  
In Vivo Models ◽  
The Brain

Abstract Background Microglia are resident immune cells in the central nervous system and central to the innate immune system. Excessive activation of microglia after subarachnoid haemorrhage (SAH) contributes greatly to early brain injury, which is responsible for poor outcomes. Dehydroepiandrosterone (DHEA), a steroid hormone enriched in the brain, has recently been found to regulate microglial activation. The purpose of this study was to address the role of DHEA in SAH. Methods We used in vivo models of endovascular perforation and in vitro models of haemoglobin exposure to illustrate the effects of DHEA on microglia in SAH. Results In experimental SAH mice, exogenous DHEA administration increased DHEA levels in the brain and modulated microglial activation. Ameliorated neuronal damage and improved neurological outcomes were also observed in the SAH mice pretreated with DHEA, suggesting neuronal protective effects of DHEA. In cultured microglia, DHEA elevated the mRNA and protein levels of Jumonji d3 (JMJD3, histone 3 demethylase) after haemoglobin exposure, downregulated the H3K27me3 level, and inhibited the transcription of proinflammatory genes. The devastating proinflammatory microglia-mediated effects on primary neurons were also attenuated by DHEA; however, specific inhibition of JMJD3 abolished the protective effects of DHEA. We next verified that DHEA-induced JMJD3 expression, at least in part, through the tropomyosin-related kinase A (TrkA)/Akt signalling pathway. Conclusions DHEA has a neuroprotective effect after SAH. Moreover, DHEA increases microglial JMJD3 expression to regulate proinflammatory/anti-inflammatory microglial activation after haemoglobin exposure, thereby suppressing inflammation.

scholarly journals An Explanation of the Underlying Mechanisms for the In Vitro and In Vivo Antiurolithic Activity of Glechoma longituba

2016 ◽  
Vol 2016 ◽  
pp. 1-11 ◽  
Author(s):  
Qiang Liang ◽  
Xiaoran Li ◽  
Wangning Zhou ◽  
Yu Su ◽  
Shenbao He ◽  
...  
Keyword(s):  
Kidney Injury ◽  
Positive Control ◽  
Potassium Citrate ◽  
Positive Control Group ◽  
Control Group ◽  
Protective Effects ◽  
In Vivo Models ◽  
Glechoma Longituba

Purpose. To use in vitro and in vivo models to evaluate Glechoma longituba extract to provide scientific evidence for this extract’s antiurolithic activity. Materials and Methods. Potassium citrate was used as a positive control group. Oxidative stress (OS) markers and the expression of osteopontin (OPN) and kidney injury molecule-1 (KIM-1) were measured to assess the protective effects of Glechoma longituba. Multiple urolithiasis-related biochemical parameters were evaluated in urine and serum. Kidneys were harvested for histological examination and the assessment of crystal deposits. Results. In vitro and in vivo experiments demonstrated that treatment with Glechoma longituba extract significantly decreased calcium oxalate- (CaOx-) induced OPN expression, KIM-1 expression, and OS compared with the positive control group (P<0.05). Additionally, in vivo rats that received Glechoma longituba extract exhibited significantly decreased CaOx deposits and pathological alterations (P<0.05) compared with urolithic rats. Significantly lower levels of oxalate, creatinine, and urea and increased citrate levels were observed among rats that received Glechoma longituba (P<0.05) compared with urolithic rats. Conclusion. Glechoma longituba has antiurolithic effects due to its possible combined effects of increasing antioxidant levels, decreasing urinary stone-forming constituents and urolithiasis-related protein expression, and elevating urinary citrate levels.

scholarly journals The emerging role of iron in heart failure and vascular calcification in CKD

2020 ◽  
Author(s):  
Paola Ciceri ◽  
Mario Cozzolino
Keyword(s):  
Heart Failure ◽  
Iron Deficiency ◽  
Vascular Calcification ◽  
Strong Association ◽  
In Vivo Models ◽  
Risk Of Death ◽  
Increased Risk ◽  
Cv Disease

Abstract Iron deficiency is a frequent comorbidity of cardiovascular (CV) diseases and nearly 50% of patients with heart failure (HF) with or without anaemia have low levels of available iron. There is a strong association between anaemia and the increase in mortality and hospitalizations in patients with CV disease and HF. Moreover, anaemia and chronic kidney disease (CKD) often coexist in patients with HF, with anaemia increasing the risk of death in these subjects and with a further increased risk in CKD population. The evidence that the treatment of iron deficiency and the increase in haemoglobin are associated with a better prognosis in HF patients has elicited new interest in the utilization of iron in HF and CKD patients. One of the central players in CV disease is vascular calcification (VC), which has been recognized as a major independent risk factor for incident CV disease and overall mortality in chronic disease patients. In this review, we summarize the evidences generated by clinical trials aimed to study the effect of iron deficiency correction, the effect of iron-based phosphate binder in in vivo models of kidney failure and the effect of iron in in vitro models of VC, trying to give an overview of the present knowledge on iron effect and its mechanisms of action.

scholarly journals Macrophage Class A Scavenger Receptor-Mediated Phagocytosis of Escherichia coli: Role of Cell Heterogeneity, Microbial Strain, and Culture Conditions In Vitro

2000 ◽  
Vol 68 (4) ◽  
pp. 1953-1963 ◽  
Author(s):  
Leanne Peiser ◽  
Peter J. Gough ◽  
Tatsuhiko Kodama ◽  
Siamon Gordon
Keyword(s):  
Escherichia Coli ◽  
Host Defense ◽  
Bacterial Strain ◽  
Chinese Hamster Ovary Cells ◽  
Culture Conditions ◽  
E Coli ◽  
Class A

ABSTRACT Macrophage class A scavenger receptors (SR-AI and SR-AII) contribute to host defense by binding polyanionic ligands such as lipopolysaccharide and lipoteichoic acid. SR-A knockout (SR-A−/−) mice are more susceptible to endotoxic shock and Listeria monocytogenes infection in vivo, possibly due to decreased clearance of lipopolysaccharide and microorganisms, respectively. We have used flow cytometry to analyze the role of SR-A and other scavenger-like receptors in phagocytosis of bacteria in vitro. Chinese hamster ovary cells stably transfected with human SR-A bound Escherichia coli and Staphylococcus aureus but ingested few organisms. Primary human monocyte-derived macrophages (Mφ) bound and ingested E. coli more efficiently, and this was partially but selectively blocked by the general SR inhibitor, poly(I). A specific and selective role for SR-A was shown, since bone marrow culture-derived Mφ from SR-A−/− mice ingested fewer E. coli organisms than did wild-type cells, while uptake of antibody-opsonized E. coli was unaffected. SR-A-dependent uptake of E. colivaried with the bacterial strain; ingestion of DH5α and K1 by SR-A−/− Mφ was reduced by 30 to 60% and 70 to 75%, respectively. Phagocytosis and endocytosis via SR-A were markedly down-modulated when Mφ were plated on serum-coated tissue culture plastic compared to bacteriologic plastic, where cell adhesion is mediated by SR-A and CR3, respectively. This paper demonstrates that SR-A can bind and ingest bacteria directly, consistent with a role in host defense in vivo, and highlights the importance of the source of the Mφ, bacterial strain, and culture conditions on receptor function in vitro.

Sign in / Sign up

Export Citation Format

Share Document