34 research outputs found
Nitric oxide contributes to learning and memory deficits observed in hypothyroid rats during neonatal and juvenile growth
INTRODUCTION: Severe cognitive impairment follows thyroid hormone deficiency during the neonatal period. The role of nitric oxide (NO) in learning and memory has been widely investigated. METHODS: This study aimed to investigate the effect of hypothyroidism during neonatal and juvenile periods on NO metabolites in the hippocampi of rats and on learning and memory. Animals were divided into two groups and treated for 60 days from the first day of lactation. The control group received regular water, whereas animals in a separate group were given water supplemented with 0.03% methimazole to induce hypothyroidism. Male offspring were selected and tested in the Morris water maze. Samples of blood were collected to measure the metabolites of NO, NO2, NO3 and thyroxine. The animals were then sacrificed, and their hippocampi were removed to measure the tissue concentrations of NO2 and NO3. DISCUSSION: Compared to the control group's offspring, serum thyroxine levels in the methimazole group's offspring were significantly lower (P<0.01). In addition, the swim distance and time latency were significantly higher in the methimazole group (P<0.001), and the time spent by this group in the target quadrant (Q1) during the probe trial was significantly lower (P<0.001). There was no significant difference in the plasma levels of NO metabolites between the two groups; however, significantly higher NO metabolite levels in the hippocampi of the methimazole group were observed compared to controls (P<0.05). CONCLUSION: These results suggest that the increased NO level in the hippocampus may play a role in the learning and memory deficits observed in childhood hypothyroidism; however, the precise underlying mechanism(s) remains to be elucidated
Salinomycin Triggers Human Colorectal Cancer HCT116 Cell Death by Targeting Unfolded Protein Responses and Autophagy Pathways
Background: Autophagy and the unfolded protein response (UPR) are important pathways in colorectal tumorigenesis and drug resistance, rendering them as potential therapeutic targets for treating this cancer. As an ionophoric polyether antibiotic, salinomycin has anti-cancer effects and overcomes drug resistance in cancer cells. Considering the minimal information on the molecular action mechanism of salinomycin in colorectal cancer (CRC), this study was designed to investigate the effect of this compound on autophagy and UPR pathways in CRC cells. Methods: The in vitro cytotoxicity of salinomycin on CRC cell line HCT116 was determined using the MTT assay by treating the cells with different concentrations of salinomycin for 24 and 48 h. The gene expression analysis of three main autophagy biomarkers (Beclin1, LC3, and P62) and two UPR biomarkers (XBP-1s and CHOP) was performed using quantitative real-time polymerase chain reaction (RT-PCR). Data were analyzed with GraphPad Prism 8 software. Results: Salinomycin had cytotoxic effects on HCT116 cells in a time- and dose-dependent manner. The expression analysis of the UPR and autophagy-related genes showed UPR activation at both 24 h and 48 h (increase of XBP-1s and CHOP), autophagy activation at 24 h (increase of Beclin 1, LC3II, and decrease of P62), and autophagy flux inhibition at 48 h (increase of Beclin 1, LC3II and P62). Conclusion: The anti-cancer activity of salinomycin against the HCT116 cell line seems to be through triggering cell death by targeting UPR and autophagy pathways. Further studies are required to confirm our results
Stevia aquatic extract protects the pancreas from streptozocin (STZ) induced damage: A stereological study
299-307In recent years, among antidiabetic medicinal herbs, Stevia received a lot of attention due to its diverse therapeutic
applications. Despite extensive reports on the effects of Stevia on the pancreas, its molecular mechanism is not clear yet. In
this study, we investigated the protective and preventive effects of oral extracts of Stevia on the pancreas through the
stereological methods in streptozocin (STZ) induced diabetic rats. Thus, 66 adult male rats were assigned to six groups
(n = 11) viz., healthy control, healthy Stevia (400 mg /kg), diabetic-control, diabetic-metformin (500 mg/kg), diabetic-Stevia
and pre-Stevia-diabetic group. Treatment with Stevia significantly reduced fasting blood sugar (FBS) and MDA compared to
the diabetic control group (P <0.05). The results indicated that the weight and the volume of the pancreas increased
significantly in all our treated groups compared to the diabetic one (P <0.05). The volume density of the pancreatic islands
and the number of beta cells increased in healthy and diabetic groups treated with Stevia (P <0.05). However, the pre-treated
diabetic rats with Stevia did not show significant preventive effects on the volume and number of beta cells as well as the
volume of islets against destructive effects of STZ. More specifically, our results confirmed the protective effects of Stevia
through restoring pancreatic cells and repairing the stereological damage induced by STZ
Simvastatin Induces Unfolded Protein Response and Enhances Temozolomide-Induced Cell Death in Glioblastoma Cells.
Glioblastoma (GBM) is the most prevalent malignant primary brain tumor with a very poor survival rate. Temozolomide (TMZ) is the common chemotherapeutic agent used for GBM treatment. We recently demonstrated that simvastatin (Simva) increases TMZ-induced apoptosis via the inhibition of autophagic flux in GBM cells. Considering the role of the unfolded protein response (UPR) pathway in the regulation of autophagy, we investigated the involvement of UPR in Simva-TMZ-induced cell death by utilizing highly selective IRE1 RNase activity inhibitor MKC8866, PERK inhibitor GSK-2606414 (PERKi), and eIF2α inhibitor salubrinal. Simva-TMZ treatment decreased the viability of GBM cells and significantly increased apoptotic cell death when compared to TMZ or Simva alone. Simva-TMZ induced both UPR, as determined by an increase in GRP78, XBP splicing, eukaryote initiation factor 2α (eIF2α) phosphorylation, and inhibited autophagic flux (accumulation of LC3β-II and inhibition of p62 degradation). IRE1 RNase inhibition did not affect Simva-TMZ-induced cell death, but it significantly induced p62 degradation and increased the microtubule-associated proteins light chain 3 (LC3)β-II/LC3β-I ratio in U87 cells, while salubrinal did not affect the Simva-TMZ induced cytotoxicity of GBM cells. In contrast, protein kinase RNA-like endoplasmic reticulum kinase (PERK) inhibition significantly increased Simva-TMZ-induced cell death in U87 cells. Interestingly, whereas PERK inhibition induced p62 accumulation in both GBM cell lines, it differentially affected the LC3β-II/LC3β-I ratio in U87 (decrease) and U251 (increase) cells. Simvastatin sensitizes GBM cells to TMZ-induced cell death via a mechanism that involves autophagy and UPR pathways. More specifically, our results imply that the IRE1 and PERK signaling arms of the UPR regulate Simva-TMZ-mediated autophagy flux inhibition in U251 and U87 GBM cells
Systemic antifungal therapy for tinea capitis in children
BACKGROUND: Tinea capitis is a common contagious fungal infection of the scalp in children. Systemic therapy is required for treatment and to prevent spread. This is an update of the original Cochrane review. OBJECTIVES: To assess the effects of systemic antifungal drugs for tinea capitis in children. SEARCH METHODS: We updated our searches of the following databases to November 2015: the Cochrane Skin Group Specialised Register, CENTRAL (2015, Issue 10), MEDLINE (from 1946), EMBASE (from 1974), LILACS (from 1982), and CINAHL (from 1981). We searched five trial registers and checked the reference lists of studies for references to relevant randomised controlled trials (RCTs). We obtained unpublished, ongoing trials and grey literature via correspondence with experts in the field and from pharmaceutical companies. SELECTION CRITERIA: RCTs of systemic antifungal therapy in children with normal immunity under the age of 18 with tinea capitis confirmed by microscopy, growth of fungi (dermatophytes) in culture or both. DATA COLLECTION AND ANALYSIS: We used standard methodological procedures expected by Cochrane. MAIN RESULTS: We included 25 studies (N = 4449); 4 studies (N = 2637) were new to this update. Terbinafine for four weeks and griseofulvin for eight weeks showed similar efficacy for the primary outcome of complete (i.e. clinical and mycological) cure in three studies involving 328 participants with Trichophyton species infections (84.2% versus 79.0%; risk ratio (RR) 1.06, 95% confidence interval (CI) 0.98 to 1.15; low quality evidence). Complete cure with itraconazole (two to six weeks) and griseofulvin (six weeks) was similar in two studies (83.6% versus 91.0%; RR 0.92, 95% CI 0.81 to 1.05; N = 134; very low quality evidence). In two studies, there was no difference between itraconazole and terbinafine for two to three weeks treatment (73.8% versus 78.8%; RR 0.93, 95% CI 0.72 to 1.19; N = 160; low quality evidence). In three studies, there was a similar proportion achieving complete cured with two to four weeks of fluconazole or six weeks of griseofulvin (41.4% versus 52.7%; RR 0.92, 95% CI 0.81 to 1.05; N = 615; moderate quality evidence). Current evidence for ketoconazole versus griseofulvin was limited. One study favoured griseofulvin (12 weeks) because ketoconazole (12 weeks) appeared less effective for complete cure (RR 0.76, 95% CI 0.62 to 0.94; low quality evidence). However, their effects appeared to be similar when the treatment lasted 26 weeks (RR 0.95, 95% CI 0.83 to 1.07; low quality evidence). Another study indicated that complete cure was similar for ketoconazole (12 weeks) and griseofulvin (12 weeks) (RR 0.89, 95% CI 0.57 to 1.39; low quality evidence). For one trial, there was no significant difference for complete cure between fluconazole (for two to three weeks) and terbinafine (for two to three weeks) (82.0% versus 94.0%; RR 0.87, 95% CI 0.75 to 1.01; N = 100; low quality evidence). For complete cure, we did not find a significant difference between fluconazole (for two to three weeks) and itraconazole (for two to three weeks) (82.0% versus 82.0%; RR 1.00, 95% CI 0.83 to 1.20; low quality evidence). This update provides new data: in children with Microsporum infections, a meta‐analysis of two studies found that the complete cure was lower for terbinafine (6 weeks) than for griseofulvin (6‐12 weeks) (34.7% versus 50.9%; RR 0.68, 95% CI 0.53 to 0.86; N = 334; moderate quality evidence). In the original review, there was no significant difference in complete cure between terbinafine (four weeks) and griseofulvin (eight weeks) in children with Microsporum infections in one small study (27.2% versus 60.0%; RR 0.45, 95% CI 0.15 to 1.35; N = 21; low quality evidence). One study provides new evidence that terbinafine and griseofulvin for six weeks show similar efficacy (49.5% versus 37.8%; RR 1.18, 95% CI 0.74 to 1.88; N = 1006; low quality evidence). However, in children infected with T. tonsurans, terbinafine was better than griseofulvin (52.1% versus 35.4%; RR 1.47, 95% CI 1.22 to 1.77; moderate quality evidence). For children infected with T. violaceum, these two regimens have similar effects (41.3% versus 45.1%; RR 0.91, 95% CI 0.68 to 1.24; low quality evidence). Additionally, three weeks of fluconazole was similar to six weeks of fluconazole in one study in 491 participants infected with T. tonsurans and M. canis (30.2% versus 34.1%; RR 0.88, 95% CI 0.68 to 1.14; low quality evidence). The frequency of adverse events attributed to the study drugs was similar for terbinafine and griseofulvin (9.2% versus 8.3%; RR 1.11, 95% CI 0.79 to 1.57; moderate quality evidence), and severe adverse events were rare (0.6% versus 0.6%; RR 0.97, 95% CI 0.24 to 3.88; moderate quality evidence). Adverse events for terbinafine, griseofulvin, itraconazole, ketoconazole, and fluconazole were all mild and reversible. All of the included studies were at either high or unclear risk of bias in at least one domain. Using GRADE to rate the overall quality of the evidence, lower quality evidence resulted in lower confidence in the estimate of effect. AUTHORS' CONCLUSIONS: Newer treatments including terbinafine, itraconazole and fluconazole are at least similar to griseofulvin in children with tinea capitis caused by Trichophyton species. Limited evidence suggests that terbinafine, itraconazole and fluconazole have similar effects, whereas ketoconazole may be less effective than griseofulvin in children infected with Trichophyton. With some interventions the proportion achieving complete clinical cure was in excess of 90% (e.g. one study of terbinafine or griseofulvin for Trichophyton infections), but in many of the comparisons tested, the proportion cured was much lower. New evidence from this update suggests that terbinafine is more effective than griseofulvin in children with T. tonsurans infection. However, in children with Microsporum infections, new evidence suggests that the effect of griseofulvin is better than terbinafine. We did not find any evidence to support a difference in terms of adherence between four weeks of terbinafine versus eight weeks of griseofulvin. Not all treatments for tinea capitis are available in paediatric formulations but all have reasonable safety profiles
The ER Stress/UPR axis in chronic obstructive pulmonary disease and idiopathic pulmonary fibrosis
Cellular protein homeostasis in the lungs is constantly disrupted by recurrent exposure to various external and internal stressors, which may cause considerable protein secretion pressure on the endoplasmic reticulum (ER), resulting in the survival and differentiation of these cell types to meet the increased functional demands. Cells are able to induce a highly conserved adaptive mechanism, known as the unfolded protein response (UPR), to manage such stresses. UPR dysregulation and ER stress are involved in numerous human illnesses, such as metabolic syndrome, fibrotic diseases, and neurodegeneration, and cancer. Therefore, effective and specific compounds targeting the UPR pathway are being considered as potential therapies. This review focuses on the impact of both external and internal stressors on the ER in idiopathic pulmonary fibrosis (IPF) and chronic obstructive pulmonary disease (COPD) and discusses the role of the UPR signaling pathway activation in the control of cellular damage and specifically highlights the potential involvement of non-coding RNAs in COPD. Summaries of pathogenic mechanisms associated with the ER stress/UPR axis contributing to IPF and COPD, and promising pharmacological intervention strategies, are also presented
The ER Stress/UPR Axis in Chronic Obstructive Pulmonary Disease and Idiopathic Pulmonary Fibrosis.
Cellular protein homeostasis in the lungs is constantly disrupted by recurrent exposure to various external and internal stressors, which may cause considerable protein secretion pressure on the endoplasmic reticulum (ER), resulting in the survival and differentiation of these cell types to meet the increased functional demands. Cells are able to induce a highly conserved adaptive mechanism, known as the unfolded protein response (UPR), to manage such stresses. UPR dysregulation and ER stress are involved in numerous human illnesses, such as metabolic syndrome, fibrotic diseases, and neurodegeneration, and cancer. Therefore, effective and specific compounds targeting the UPR pathway are being considered as potential therapies. This review focuses on the impact of both external and internal stressors on the ER in idiopathic pulmonary fibrosis (IPF) and chronic obstructive pulmonary disease (COPD) and discusses the role of the UPR signaling pathway activation in the control of cellular damage and specifically highlights the potential involvement of non-coding RNAs in COPD. Summaries of pathogenic mechanisms associated with the ER stress/UPR axis contributing to IPF and COPD, and promising pharmacological intervention strategies, are also presented