Expression of norA, norB and norC efflux pump genes mediating fluoroquinolones resistance in MRSA isolates.

INTRODUCTION: Although fluoroquinolones are used to treat methicillin-resistant Staphylococcus aureus (MRSA)-induced infections, acquisition of antibiotic resistance by bacteria has impaired their clinical relevance. We aimed to evaluate the frequency of norA, norB, and norC efflux pump genes-mediating fluoroquinolones resistance and measure their expression levels in MRSA isolates. METHODOLOGY: 126 S. aureus isolates were collected from different clinical samples of adult hospitalized patients and identified by conventional microbiological methods. MRSA was diagnosed by cefoxitin disc diffusion method and minimum inhibitory concentration (MIC) of ciprofloxacin by broth microdilution method. The expression levels of efflux pump genes were measured by quantitative real-time polymerase chain reaction (qRT-PCR). RESULTS: 80 (63.5%) MRSA isolates were identified and showed high level of resistance to erythromycin (80%), gentamicin (75%), clindamycin (65%) and ciprofloxacin (60 %). norA, norB and norC were detected in 75%, 35% and 55% of the MRSA isolates respectively. norC was the most commonly overexpressed gene measured by qRT-PCR, occurring in 40% of MRSA isolates, followed by norA (35%) and norB (30%). The expression of these genes was significantly higher in ciprofloxacin-resistant than quantitative real-time PCR ciprofloxacin-sensitive MRSA isolates. CONCLUSIONS: This study showed high prevalence and overexpression of efflux pump genes among MRSA isolates which indicates the significant role of these genes in the development of multidrug resistance against antibiotics including fluoroquinolones.

Stattic ameliorates the cecal ligation and puncture-induced cardiac injury in septic mice via IL-6-gp130-STAT3 signaling pathway.

AIM: Sepsis-induced cardiac dysfunction is the leading cause of higher morbidity and mortality with poor prognosis in septic patients. Our recent previous investigation provides evidence of the hallmarks of signal transducer and activator of transcription3 (STAT3) activation in sepsis and targeting of STAT3 with Stattic, a small-molecule inhibitor of STAT3, has beneficial effects in various septic tissues. We investigated the possible cardioprotective effects of Stattic on cardiac inflammation and dysfunction in mice with cecal ligation and puncture (CLP)-induced sepsis. MAIN METHODS: A polymicrobial sepsis model was induced by CLP in mice and Stattic (25 mg/kg) was intraperitoneally given at one and twelve hours after CLP operation. The cecum was exposed in sham-control mice without CLP. After 18 h of surgery, electrocardiogram (ECG) for anaesthized mice was registered followed by collecting of samples of blood and tissues for bimolecular and histopathological assessments. Myeloperoxidase, a marker of neutrophil infiltration, was assessed immunohistochemically. KEY FINDINGS: CLP profoundly impaired cardiac functions as evidenced by ECG changes in septic mice as well as elevation of cardiac enzymes, and inflammatory markers with myocardial histopathological and immunohistochemical alterations. While, Stattic markedly reversed the CLP-induced cardiac abnormalities and restored the cardiac function by its anti-inflammatory activities. SIGNIFICANCE: Stattic treatment had potential beneficial effects against sepsis-induced cardiac inflammation, dysfunction and damage. Its cardioprotective effects were possibly attributed to its anti-inflammatory activities by targeting STAT3 and downregulation of IL-6 and gp130. Our investigations suggest that Stattic could be a promising target for management of cardiac sepsis and inflammation-related cardiac damage.

The immunomodulatory effects of probiotics and azithromycin in dextran sodium sulfate-induced ulcerative colitis in rats via TLR4-NF-κB and p38-MAPK pathway.

Ulcerative colitis (UC), a chronic autoimmune disease of the gut with a relapsing and remitting nature, considers a major health-care problem. DSS is a well-studied pharmacologically-induced model for UC. Toll-Like Receptor 4 (TLR4) and its close association with p-38-Mitogen-Activated Protein Kinase (p-38 MAPK) and nuclear factor kappa B (NF-κB) has important regulatory roles in inflammation and developing UC. Probiotics are gaining popularity for their potential in UC therapy. The immunomodulatory and anti-inflammatory role of azithromycin in UC remains a knowledge need. In the present rats-established UC, the therapeutic roles of oral probiotics (60 billion probiotic bacteria per kg per day) and azithromycin (40 mg per kg per day) regimens were evaluated by measuring changes in disease activity index, macroscopic damage index, oxidative stress markers, TLR4, p-38 MAPK, NF-κB signaling pathway in addition to their molecular downstream; tumor necrosis factor alpha (TNFα), interleukin (IL)1ß, IL6, IL10 and inducible nitric oxide synthase (iNOS). After individual and combination therapy with probiotics and azithromycin regimens, the histological architecture of the UC improved with restoration of intestinal tissue normal architecture. These findings were consistent with the histopathological score of colon tissues. Each separate regimen lowered the remarkable TLR4, p-38 MAPK, iNOS, NF-κB as well as TNFα, IL1ß, IL6 and MDA expressions and elevated the low IL10, glutathione and superoxide dismutase expressions in UC tissues. The combination regimen possesses the most synergistic beneficial effects in UC that, following thorough research, should be incorporated into the therapeutic approach in UC to boost the patients' quality of life.

Cardioprotective and renoprotective effects of venlafaxine on cisplatin-induced cardiotoxicity and nephrotoxicity in rats.

AIM: The current work aims to demonstrate the potential defensive function of venlafaxine (VLF) in cardiotoxicity and nephrotoxicity caused by cisplatin (CP), that could be by modulating extracellular signal-regulated kinase (ERK)1/2 and nicotinamide adenine dinucleotide phosphate (NAPDH) oxidase NOX4 pathways. MAIN METHODS: Five groups of rats were used, as follow: three control groups (control, carboxymethyl cellulose, and VLF), CP group got CP once (7 mg/kg, intraperitoneally, i.p.), and (CP+ VLF) group got CP once then after 1 h they got VLF {50 mg/kg daily, orally for 14 days}. At the end of the study; electrocardiogram (ECG) was recorded for anaesthized rats then blood samples and tissues were taken for biochemical and histopathological investigations. Caspase 3, a marker of cellular damage and apoptosis was detected by immunohistochemistry. KEY FINDINGS: CP treatment significantly impaired cardiac functions as evidenced by changes in rats' ECG. Cardiac enzymes, renal markers and inflammatory markers were increased with decreased activities of the total antioxidant capacity, superoxide dismutase and glutathione peroxidase. Also, ERK1/2 and NOX4 were upregulated with histopathological and immunohistochemical alterations of heart and kidney. While, VLF markedly alleviated CP-induced functional cardiac abnormalities and improved ECG pattern. It reduced both cardiac and renal biomarkers, oxidative stress, proinflammatory cytokine with ERK1/2 and NOX4 downregulation, improved the histopathological and immunohistochemical changes induced by cisplatin in heart and kidney. SIGNIFICANCE: VLF treatment impedes cardiotoxicity and nephrotoxicity caused by CP. This beneficial effect was mediated through reduction of oxidative stress, inflammation, and apoptosis by targeting the ERK1/2 and NOX4.

The GSTP1/MAPKs/BIM/SMAC modulatory actions of nitazoxanide: Bioinformatics and experimental evidence in subcutaneous solid Ehrlich carcinoma-inoculated mice.

AIMS: Ehrlich ascites carcinoma and its subcutaneous inoculated solid tumour form (SEC) are reliable models for chemotherapeutic molecular targets exploration. Novel chemotherapeutic approaches are identified as molecular targets for intrinsic apoptosis, like the modulation of the second mitochondria-derived activator of caspases (SMAC). SMAC is a physiological substrate of mitogen-activated protein kinases (MAPKs). Glutathione-S-transferase P1 (GSTP1) and its close association with MAPKs play an important role in malignant cell proliferation, metastasis, and resistance to chemotherapeutics. Nitazoxanide (NTZ) is an emerging cancer therapy and its targeted GSTP1 evidence remains a knowledge need. MAIN METHODS: In the present mice-established SEC, the chemotherapeutic roles of oral NTZ (200 mg/kg/day) and 5-fluorouracil (5-FU; 20 mg/kg/day, intraperitoneally) regimens were evaluated by measuring changes in tumour mass, the tumour MAPKs, cytochrome c, Bcl-2 interacting mediator of cell death (BIM), and SMAC signalling pathway in addition to its molecular downstream; caspases 3 and 9. KEY FINDINGS: Computational analysis for these target protein interactions showed direct-ordered interactions. After individual therapy with NTZ and 5-FU regimens, the histological architecture of the extracted tumour discs revealed decreases in viable tumour regions with significant necrosis surrounds. These findings were consistent with gross tumour sizes. Each separate regimen lowered the remarkable GSTP1 and elevated the low MAPKs expressions, cytochrome c, BIM, SMAC, and caspases 3, and 9 in EST tissues. SIGNIFICANCE: The chemotherapeutic activity of NTZ in SEC was proven. Additionally, NTZ possesses a SMAC modulatory activity that, following thorough research, should be taken into consideration as a chemotherapeutic approach in solid tumours.

Acute toxic effects of new synthetic cannabinoid on brain: Neurobehavioral and Histological: Preclinical studies.

The psychoactive effects of new synthetic cannabinoids (SCs), MDMB-4en-PINACA, are being marketed as a blend of herbs and spices. This study aims to determine the behavioral, neurochemical, histopathological, and immunohistochemical alterations associated with the acute toxicity of MDMB-4en-PINACA compounds. METHODS: Adult male albino rats were administered various toxic doses of the drug (1.5, 3, and 6 mg/kg), and behavioral studies were conducted 2 and 24 h later; animals were then sacrificed. Histopathological and neurochemical examinations were performed. Two hours after intraperitoneal. RESULTS: Intraperitoneal injection of MDMB-4en-PINACA, horizontal movement, the number of stops, and mobility ratio were significantly impaired, along with coordination and balance. In addition, it led to a decline in spatial learning and memory, and neurotransmitter concentrations decreased significantly in a dose-dependent manner. Further examination of the cerebral cortex and hippocampus histopathology revealed pathological degeneration of small pyramidal cells. CONCLUSION: Thus, these findings revealed that MDMB-4en-PINACA interferes with hippocampal function and impairs cognitive performance, highlighting the cognitive risk associated with SC abuse.

Protective effects of evening primrose oil on behavioral activities, nigral microglia and histopathological changes in a rat model of rotenone-induced parkinsonism.

Parkinson's disease (PD) is a neurodegenerative illness described as damage to dopaminergic neurons. There is increasing evidence that neuroinflammatory activity mediated by microglia is extensively involved in the initiation and development of PD. This study assessed the protective effect of evening primrose oil [EPO] as an anti-inflammatory mediator in rotenone-induced Parkinsonism in rats. Forty-eight adult male albino rats were distributed into four groups. Group I: control. Group II: rotenone [1.5 mg/kg/48 h] was administered subcutaneously to the rats. Groups III and IV: the rats had rotenone plus daily oral [EPO] 5 and 10 mg/kg respectively. After 24 days, motor behaviour was assessed by the open field and rotarod tests. The brain striata were isolated and tested for tumor necrosis factor (TNF)-α, interleukin 6, NF-B [nuclear factor-kappa B], and dopamine levels. The mid-brain tissues were processed for light and electron microscopy examinations, and immunohistochemical staining for tyrosine hydroxylase [TH], and microglia cells' markers: [CD68 and IBA1]. Results revealed that rotenone-treated rats had poor motor function, a significantly increased striatal level of inflammatory markers, markedly shrunken neurons, degeneration, pyknotic neuroglia, neuropil vacuolation, markedly destructed swollen mitochondria with loss of their cristae, and dilated rough endoplasmic reticulum, as well as decreased TH and increased CD68 and IBA1-positive cells. Treatment with EPO ameliorates all the neuropathological changes of rotenone in the rat brain. In conclusion, EPO enhanced the motor performance, reduced the inflammatory marker levels, restored dopamine levels, and ameliorated the neurohistopathological lesions of rats with experimental parkinsonism, suggesting its neuroprotective and anti-inflammatory effects.

Beneficial effect of STAT3 decoy oligodeoxynucleotide transfection on organ injury and mortality in mice with cecal ligation and puncture-induced sepsis.

Sepsis is a major clinical challenge with unacceptably high mortality. The signal transducers and activators of transcription (STAT) family of transcription factors is known to activate critical mediators of cytokine responses, and, among this family, STAT3 is implicated to be a key transcription factor in both immunity and inflammatory pathways. We investigated whether in vivo introduction of synthetic double-stranded STAT3 decoy oligodeoxynucleotides (ODNs) can provide benefits for reducing organ injury and mortality in mice with cecal ligation and puncture (CLP)-induced polymicrobial sepsis. We found that STAT3 was rapidly activated in major end-organ tissues following CLP, which was accompanied by activation of the upstream kinase JAK2. Transfection of STAT3 decoy ODNs downregulated pro-inflammatory cytokine/chemokine overproduction in CLP mice. Moreover, STAT3 decoy ODN transfection significantly reduced the increases in tissue mRNAs and proteins of high mobility group box 1 (HMGB1) and strongly suppressed the excessive elevation in serum HMGB1 levels in CLP mice. Finally, STAT3 decoy ODN administration minimized the development of sepsis-driven major end-organ injury and led to a significant survival advantage in mice after CLP. Our results suggest a critical role of STAT3 in the sepsis pathophysiology and the potential usefulness of STAT3 decoy ODNs for sepsis gene therapy.

Vascular endothelial growth factor contributes to lung vascular hyperpermeability in sepsis-associated acute lung injury.

Vascular endothelial growth factor (VEGF) is a prime regulator of vascular permeability. Acute lung injury (ALI) is characterized by high-permeability pulmonary edema in addition to refractory hypoxemia and diffuse pulmonary infiltrates. In this study, we examined whether VEGF can be implicated as a pulmonary vascular permeability factor in sepsis-associated ALI. We found that a great increase in lung vascular leak occurred in mice instilled intranasally with lipopolysaccharide (LPS), as assessed by IgM levels in bronchoalveolar lavage fluid. Treatment with the VEGF-neutralizing monoclonal antibody bevacizumab significantly reduced this hyperpermeability response, suggesting active participation of VEGF in non-cardiogenic lung edema associated with LPS-induced ALI. However, this was not solely attributable to excessive levels of intrapulmonary VEGF. Expression levels of VEGF were significantly reduced in lung tissues from mice with both intranasal LPS administration and cecal ligation and puncture (CLP)-induced sepsis, which may stem from decreases in non-endothelial cells-dependent VEGF production in the lungs. In support of this assumption, stimulation with LPS and interferon-γ (IFN-γ) significantly increased VEGF in human pulmonary microvascular endothelial cells (HPMECs) at mRNA and protein levels. Furthermore, a significant rise in plasma VEGF levels was observed in CLP-induced septic mice. The increase in VEGF released from HPMECs after LPS/IFN-γ challenge was completely blocked by either specific inhibitor of mitogen-activated protein kinase (MAPK) subgroups. Taken together, our results indicate that VEGF can contribute to the development of non-cardiogenic lung edema in sepsis-associated ALI due to increased VEGF secretion from pulmonary vascular endothelial cells through multiple MAPK-dependent pathways.