scholarly journals Antibacterial Activity of a Competence-Stimulating Peptide in Experimental Sepsis Caused by Streptococcus pneumoniae

2004 ◽  
Vol 48 (12) ◽  
pp. 4725-4732 ◽  
Author(s):  
Marco R. Oggioni ◽  
Francesco Iannelli ◽  
Susanna Ricci ◽  
Damiana Chiavolini ◽  
Riccardo Parigi ◽  
...  
Keyword(s):  
Streptococcus Pneumoniae ◽  
Histidine Kinase ◽  
Drug Target ◽  
Systemic Disease ◽  
Experimental Sepsis ◽  
Inhibition Of Growth ◽  
Peptide Pheromone ◽  
Set Up

ABSTRACT Streptococcus pneumoniae, a major cause of human disease, produces a 17-mer autoinducer peptide pheromone (competence-stimulating peptide [CSP]) for the control of competence for genetic transformation. Due to previous work linking CSP to stress phenotypes, we set up an in vivo sepsis model to assay its effect on virulence. Our data demonstrate a significant increase in the rates of survival of mice, reductions of blood S. pneumoniae counts, and prolonged times to death for mice treated with CSP. In vitro the dose of CSP used in the animal model produced a transitory inhibition of growth. When a mutant with a mutation in the CSP sensor histidine kinase was assayed, no bacteriostatic phenotype was detected in vitro and no change in disease outcome was observed in vivo. The data demonstrate that CSP, which induces in vitro a temporary growth arrest through stimulation of its cognate histidine kinase receptor, is able to block systemic disease in mice. This therapeutic effect is novel, in that the drug-like effect is obtained by stimulation, rather than inhibition, of a bacterial drug target.

Rapid, Refined, and Robust Method for Expression, Purification, and Characterization of Recombinant Human Amyloid-beta M1-42

2019 ◽  
Author(s):  
Priya Prakash ◽  
Travis Lantz ◽  
Krupal P. Jethava ◽  
Gaurav Chopra
Keyword(s):  
Amyloid Beta ◽  
Western Blots ◽  
Force Microscopy ◽  
E Coli ◽  
Atomic Force ◽  
Set Up ◽  
Short Time

Amyloid plaques found in the brains of Alzheimer’s disease (AD) patients primarily consists of amyloid beta 1-42 (Ab42). Commercially, Ab42 is synthetized using peptide synthesizers. We describe a robust methodology for expression of recombinant human Ab(M1-42) in Rosetta(DE3)pLysS and BL21(DE3)pLysS competent E. coli with refined and rapid analytical purification techniques. The peptide is isolated and purified from the transformed cells using an optimized set-up for reverse-phase HPLC protocol, using commonly available C18 columns, yielding high amounts of peptide (~15-20 mg per 1 L culture) in a short time. The recombinant Ab(M1-42) forms characteristic aggregates similar to synthetic Ab42 aggregates as verified by western blots and atomic force microscopy to warrant future biological use. Our rapid, refined, and robust technique to purify human Ab(M1-42) can be used to synthesize chemical probes for several downstream in vitro and in vivo assays to facilitate AD research.

scholarly journals Multiple screening approaches reveal HDAC6 as a novel regulator of glycolytic metabolism in triple-negative breast cancer

2021 ◽  
Vol 7 (3) ◽  
pp. eabc4897
Author(s):  
Catríona M. Dowling ◽  
Kate E. R. Hollinshead ◽  
Alessandra Di Grande ◽  
Justin Pritchard ◽  
Hua Zhang ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Triple Negative Breast Cancer ◽  
Histone Deacetylase Inhibitors ◽  
Triple Negative ◽  
Mitochondrial Apoptosis ◽  
Glycolytic Metabolism ◽  
Set Up ◽  
Screening Approaches

Triple-negative breast cancer (TNBC) is a subtype of breast cancer without a targeted form of therapy. Unfortunately, up to 70% of patients with TNBC develop resistance to treatment. A known contributor to chemoresistance is dysfunctional mitochondrial apoptosis signaling. We set up a phenotypic small-molecule screen to reveal vulnerabilities in TNBC cells that were independent of mitochondrial apoptosis. Using a functional genetic approach, we identified that a “hit” compound, BAS-2, had a potentially similar mechanism of action to histone deacetylase inhibitors (HDAC). An in vitro HDAC inhibitor assay confirmed that the compound selectively inhibited HDAC6. Using state-of-the-art acetylome mass spectrometry, we identified glycolytic substrates of HDAC6 in TNBC cells. We confirmed that inhibition or knockout of HDAC6 reduced glycolytic metabolism both in vitro and in vivo. Through a series of unbiased screening approaches, we have identified a previously unidentified role for HDAC6 in regulating glycolytic metabolism.

scholarly journals In Vitro and In Vivo Activities of DA-7867, a New Oxazolidinone, against Aerobic Gram-Positive Bacteria

2005 ◽  
Vol 49 (6) ◽  
pp. 2498-2500 ◽  
Author(s):  
Eun Jeong Yoon ◽  
Yeong Woo Jo ◽  
Sung Hak Choi ◽  
Tae Ho Lee ◽  
Jae Keol Rhee ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Streptococcus Pneumoniae ◽  
Gram Positive ◽  
Methicillin Resistant ◽  
Gram Positive Bacteria ◽  
Vancomycin Resistant Enterococci ◽  
Infection Models ◽  
Vancomycin Resistant

ABSTRACT In vitro and in vivo activities of DA-7867 were assessed against methicillin-resistant Staphylococcus aureus, vancomycin-resistant enterococci, and penicillin-resistant Streptococcus pneumoniae. All isolates were inhibited by DA-7867 at ≤0.78 μg/ml, a four-times-lower concentration than that of inhibition by linezolid. For murine infection models, DA-7867 also exhibited greater efficacy than linezolid against all isolates tested.

scholarly journals Amount of RNA secondary structure required to induce an alternative splice.

1987 ◽  
Vol 7 (9) ◽  
pp. 3194-3198 ◽  
Author(s):  
D Solnick ◽  
S I Lee
Keyword(s):  
Alternative Splicing ◽  
Secondary Structure ◽  
Alternative Splice ◽  
Rna Secondary Structure ◽  
Secondary Structures ◽  
Splice Sites ◽  
Perfect Complementarity ◽  
Set Up

We set up an alternative splicing system in vitro in which the relative amounts of two spliced RNAs, one containing and the other lacking a particular exon, were directly proportional to the length of an inverted repeat inserted into the flanking introns. We then used the system to measure the effect of intramolecular complementarity on alternative splicing in vivo. We found that an alternative splice was induced in vivo only when the introns contained more than approximately 50 nucleotides of perfect complementarity, that is, only when the secondary structure was much more stable than most if not all possible secondary structures in natural mRNA precursors. We showed further that intron insertions containing long complements to splice sites and a branch point inhibited splicing in vitro but not in vivo. These results raise the possibility that in cells most pre-mRNA secondary structures either are not maintained long enough to influence splicing choices, or never form at all.

scholarly journals lncRNA Chronos is an aging-induced inhibitor of muscle hypertrophy

2017 ◽  
Vol 216 (11) ◽  
pp. 3497-3507 ◽  
Author(s):  
Ronald L Neppl ◽  
Chia-Ling Wu ◽  
Kenneth Walsh
Keyword(s):  
Skeletal Muscle ◽  
Noncoding Rna ◽  
Muscle Hypertrophy ◽  
Systemic Disease ◽  
Noncoding Rnas ◽  
Rapid Progression ◽  
Gradual Loss ◽  
Epigenetic Modulation

Skeletal muscle exhibits remarkable plasticity in its ability to modulate its mass in response to the physiologic changes associated with functional use, systemic disease, and aging. Although a gradual loss of muscle mass normally occurs with advancing age, its increasingly rapid progression results in sarcopenia in a subset of individuals. The identities of muscle-enriched, long noncoding RNAs that regulate this process are unknown. Here, we identify a long noncoding RNA, named Chronos, whose expression in muscle is positively regulated with advancing age and negatively regulated during Akt1-mediated growth. Inhibition of Chronos induces myofiber hypertrophy both in vitro and in vivo, in part, through the epigenetic modulation of Bmp7 signaling.

scholarly journals Characterization of the Anti-Inflammatory Capacity of IL-10-Producing Neutrophils in Response to Streptococcus pneumoniae Infection

2021 ◽  
Vol 12 ◽  
Author(s):  
Liliana A. González ◽  
Felipe Melo-González ◽  
Valentina P. Sebastián ◽  
Omar P. Vallejos ◽  
Loreani P. Noguera ◽  
...  
Keyword(s):  
Streptococcus Pneumoniae ◽  
Lung Injury ◽  
Interleukin 10 ◽  
Effector Cells ◽  
Cellular Source ◽  
Lung Histopathology ◽  
Morphological Differences ◽  
Direct Recognition

Neutrophils are immune cells classically defined as pro-inflammatory effector cells. However, current accumulated evidence indicates that neutrophils have more versatile immune-modulating properties. During acute lung infection with Streptococcus pneumoniae in mice, interleukin-10 (IL-10) production is required to temper an excessive lung injury and to improve survival, yet the cellular source of IL-10 and the immunomodulatory role of neutrophils during S. pneumoniae infection remain unknown. Here we show that neutrophils are the main myeloid cells that produce IL-10 in the lungs during the first 48 h of infection. Importantly, in vitro assays with bone-marrow derived neutrophils confirmed that IL-10 can be induced by these cells by the direct recognition of pneumococcal antigens. In vivo, we identified the recruitment of two neutrophil subpopulations in the lungs following infection, which exhibited clear morphological differences and a distinctive profile of IL-10 production at 48 h post-infection. Furthermore, adoptive transfer of neutrophils from WT mice into IL-10 knockout mice (Il10-/-) fully restored IL-10 production in the lungs and reduced lung histopathology. These results suggest that IL-10 production by neutrophils induced by S. pneumoniae limits lung injury and is important to mediate an effective immune response required for host survival.

scholarly journals Ultrasound-Mediated Drug Delivery With a Clinical Ultrasound System: In Vitro Evaluation

2021 ◽  
Vol 12 ◽  
Author(s):  
Josanne S. de Maar ◽  
Charis Rousou ◽  
Benjamin van Elburg ◽  
Hendrik J. Vos ◽  
Guillaume P.R. Lajoinie ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Clinical Translation ◽  
Drug Uptake ◽  
Single Element ◽  
Hydrophilic Drug ◽  
Ultrasound System ◽  
Fadu Cells ◽  
Set Up

Chemotherapy efficacy is often reduced by insufficient drug uptake in tumor cells. The combination of ultrasound and microbubbles (USMB) has been shown to improve drug delivery and to enhance the efficacy of several drugs in vitro and in vivo, through effects collectively known as sonopermeation. However, clinical translation of USMB therapy is hampered by the large variety of (non-clinical) US set-ups and US parameters that are used in these studies, which are not easily translated to clinical practice. In order to facilitate clinical translation, the aim of this study was to prove that USMB therapy using a clinical ultrasound system (Philips iU22) in combination with clinically approved microbubbles (SonoVue) leads to efficient in vitro sonopermeation. To this end, we measured the efficacy of USMB therapy for different US probes (S5-1, C5-1 and C9-4) and US parameters in FaDu cells. The US probe with the lowest central frequency (i.e. 1.6 MHz for S5-1) showed the highest USMB-induced intracellular uptake of the fluorescent dye SYTOX™ Green (SG). These SG uptake levels were comparable to or even higher than those obtained with a custom-built US system with optimized US parameters. Moreover, USMB therapy with both the clinical and the custom-built US system increased the cytotoxicity of the hydrophilic drug bleomycin. Our results demonstrate that a clinical US system can be used to perform USMB therapy as efficiently as a single-element transducer set-up with optimized US parameters. Therefore, future trials could be based on these clinical US systems, including validated US parameters, in order to accelerate successful translation of USMB therapy.

scholarly journals Antimicrobial Peptides Epinecidin-1 and Beta-Defesin-3 Are Effective against a Broad Spectrum of Antibiotic-Resistant Bacterial Isolates and Increase Survival Rate in Experimental Sepsis

Antibiotics ◽  
2022 ◽  
Vol 11 (1) ◽  
pp. 76
Author(s):  
Albert Bolatchiev
Keyword(s):  
Antibacterial Activity ◽  
Survival Rate ◽  
Antimicrobial Peptides ◽  
Lethal Dose ◽  
Experimental Models ◽  
Experimental Sepsis ◽  
Epinephelus Coioides ◽  
Sterile Saline

The antimicrobial peptides human Beta-defensin-3 (hBD-3) and Epinecidin-1 (Epi-1; by Epinephelus coioides) could be a promising tool to develop novel antibacterials to combat antibiotic resistance. The antibacterial activity of Epi-1 + vancomycin against methicillin-resistant Staphylococcus aureus (22 isolates) and Epi-1 + hBD-3 against carbapenem-resistant isolates of Klebsiella pneumoniae (n = 23), Klebsiella aerogenes (n = 17), Acinetobacter baumannii (n = 9), and Pseudomonas aeruginosa (n = 13) was studied in vitro. To evaluate the in vivo efficacy of hBD-3 and Epi-1, ICR (CD-1) mice were injected intraperitoneally with a lethal dose of K. pneumoniae or P. aeruginosa. The animals received a single injection of either sterile saline, hBD-3 monotherapy, meropenem monotherapy, hBD-3 + meropenem, or hBD-3 + Epi-1. Studied peptides showed antibacterial activity in vitro against all studied clinical isolates in a concentration of 2 to 32 mg/L. In both experimental models of murine sepsis, an increase in survival rate was seen with hBD-3 monotherapy, hBD-3 + meropenem, and hBD-3 + Epi-1. For K. pneumoniae-sepsis, hBD-3 was shown to be a promising option in overcoming the resistance of Klebsiella spp. to carbapenems, though more research is needed. In the P. aeruginosa-sepsis model, the addition of Epi-1 to hBD-3 was found to have a slightly reduced mortality rate compared to hBD-3 monotherapy.

scholarly journals Antioxidant Effects of Eryngium carlinae in Diabetic Rats

2018 ◽  
Vol 6 (5) ◽  
Author(s):  
Diana García-Cerrillo ◽  
Ruth Noriega-Cisneros ◽  
Donovan Peña-Montes ◽  
Maribel Huerta-Cervantes ◽  
Mónica Silva-Ríos ◽  
...  
Keyword(s):  
Metabolic Diseases ◽  
Systemic Disease ◽  
Cardiac Injury ◽  
Thiobarbituric Acid ◽  
Diabetic Rats ◽  
Cardiovascular Risks ◽  
Thiobarbituric Acid Reactive Substances ◽  
Antioxidant Effects

Metabolic diseases have increased considerably such as diabetes mellitus (DM). Since diabetes is a systemic disease, it implies high cardiovascular risks. It has been widely established that cardiac injury is related to mitochondrial dysfunction through increment of reactive oxygen species (ROS). Synthetic antioxidants can have important side effects; therefore natural sources may represent a better option. Traditional Mexican medicine has been using Eryngium carlinae (EC) for medical treatment. Also our group showed that hexanic extract possesses in vitro antioxidant capacity. Experimental diabetes in Wistar rats was generated by streptozotocin (STZ) and hexanic extract of EC was supplied for 7 weeks (30 mg/kg). Cholesterol, triacylglycerides, glucose, and thiobarbituric acid reactive substances (TBARS) levels were determined in serum. Mitochondria from left ventricle were used in the quantification of TBARS, reduced glutathione, nitric oxide (NO) levels and activity of superoxide dismutase (SOD) enzyme was performed.  Biochemical parameters of glucose and triacylglycerides, as well as TBARS levels in serum show a significant reduction in diabetic group supplied with EC hexanic extract. Thus, we can conclude that the EC hexanic extract possesses antioxidant activity in vitro, and in vivo, by reducing glucose and triacylglycerides levels during hyperglycemia, which may eventually reduce the risk of developing diabetic cardiomyopathy.

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