3‐Keto‐1,5‐bisphosphonates Alleviate Serum‐Oxidative Stress in the High‐fat Diet Induced Obesity in Rats

Obesity has become a leading global health problem owing to its strong association with a high incidence of oxidative stress. Many epidemiologic studies showed that an antioxidant supplementation decreases the state of oxidative stress. In the present work, a HFD ‐induced rat obesity and oxidative stress were used to investigate the link between fat deposition and serum‐oxidative stress markers. We also studied the effect of a chronic administration of 3‐keto‐1,5‐bisphosphonates 1 (a & b) (40 μg/kg/8 weeks/i.p.). Exposure of rats to HFD during 16 weeks induced fat deposition, weight gain and metabolic disruption characterized by an increase in cholesterol, triglyceride and glycemia levels, and a decrease in ionizable calcium and free iron concentrations. HFD also induced serum‐oxidative stress status vocalized by an increase in ROS ( H ₂ O ₂ ), MDA and PC levels, with a decrease in antioxidant enzyme activity ( CAT , GP x , SOD ). Importantly, 3‐keto‐1,5‐bisphosphonates corrected all the deleterious effects of HFD treatment in vivo, but it failed to inhibit lipases in vitro and in vivo. These studies suggest that 3‐keto‐1,5‐bisphosphonates 1 could be considered as safe antioxidant agents that should also find other potential biological applications.     

HRAS germline mutations impair LKB1/AMPK signaling and mitochondrial homeostasis in Costello syndrome models

Germline mutations that activate genes in the canonical RAS/MAPK signaling pathway are responsible for rare human developmental disorders known as RASopathies. Here, we analyzed the molecular determinants of Costello syndrome (CS) using a mouse model expressing HRAS p.G12S, patient skin fibroblasts, hiPSC-derived human cardiomyocytes, a HRAS p.G12V zebrafish model, and human fibroblasts expressing lentiviral constructs carrying HRAS p.G12S or HRAS p.G12A mutations. The findings revealed alteration of mitochondrial proteostasis and defective oxidative phosphorylation in the heart and skeletal muscle of CS mice that were also found in the cell models of the disease. The underpinning mechanisms involved the inhibition of the AMPK signaling pathway by mutant forms of HRAS, leading to alteration of mitochondrial proteostasis and bioenergetics. Pharmacological activation of mitochondrial bioenergetics and quality control restored organelle function in HRAS p.G12A and p.G12S cell models, reduced left ventricle hypertrophy in CS mice, and diminished the occurrence of developmental defects in the CS zebrafish model. Collectively, these findings highlight the importance of mitochondrial proteostasis and bioenergetics in the pathophysiology of RASopathies and suggest that patients with CS may benefit from treatment with mitochondrial modulators.     

Dynamic history of low-grade gliomas before and after temozolomide treatment

OBJECTIVE: To evaluate the natural progression and the impact of temozolomide in low-grade gliomas and to correlate these changes with the profile of genetic alterations. METHODS: The mean tumor diameter (MTD) of low-grade gliomas was evaluated on serial magnetic resonance images before (n = 39), during, and after (n = 107) treatment with neoadjuvant temozolomide. MTD growth curves were correlated with chromosomes 1p-19q loss and p53 overexpression in the tumors. RESULTS: Before temozolomide onset, MTD increased linearly over time, indicating a continuous growth that was significantly slower in 1p-19q deleted tumors (3.4 vs 5.9mm/year; p = 0.0016) and in tumors that did not overexpress p53 (4.2 vs 6.3mm/year; p = 0.05). During temozolomide treatment, almost all patients (92%) experienced initial decrease of MTD. Subsequently, some tumors started to resume growth despite continuous administration of temozolomide, with a lower rate of relapse in 1p-19q deleted tumors (16.6 vs 58%; p = 0.0004) and in tumors that did not overexpress p53 (26 vs 68%; p = 0.003). When temozolomide was discontinued in the absence of tumor progression, a majority of tumors resumed their progressive growth within a year. INTERPRETATION: Untreated low-grade gliomas grow continuously at a rate that is influenced by the genetic alterations of the tumors. Temozolomide reverses this pattern at the onset, but this effect is often brief in patients whose tumors overexpress p53 and do not harbor the 1p-19q codeletion, suggesting acquired chemoresistance. A majority of tumors will resume their growth when treatment is discontinued, raising the issue of the optimal duration of treatment in continuously responding patients.     

PR interval prolongation is significantly associated with aortic root abscess: An age‐ and gender‐matched study

BackgroundElectrocardiographic abnormalities, such as PR interval prolongation, have been anecdotally reported in patients with aortic root abscess (ARA). An electrocardiographic marker may be useful in identifying those patients with aortic valve endocarditis who may progress to ARA. The objective of this study is to evaluate the change in the PR interval in patients with surgically confirmed ARA and compare it to age‐ and gender‐matched controls with echocardiographically or surgically confirmed aortic valve endocarditis but without aortic root abscess and those hospitalized with diagnoses other than endocarditis.MethodsPatients were eligible for enrollment if they were 18 years or older and were hospitalized for either ARA, aortic valve endocarditis, or for unrelated reasons and had at least one 12‐lead electrocardiogram (ECG) prior to or on the day of hospitalization and at least one ECG after hospitalization but prior to any cardiac surgical procedure. Delta PR interval, defined as the difference between the pre‐ and post‐admission PR interval, was the primary outcome of interest. The patients in the ARA group were age‐ and gender‐matched to patients with aortic valve endocarditis and to those without endocarditis. Comparisons of demographic variables and study outcomes were performed.ResultsEighteen patients with surgically confirmed ARA were enrolled. These patients were age‐ and gender‐matched to 19 patients with aortic valve endocarditis and 18 patients with no past history or evidence of endocarditis during hospitalization. No difference was noted in the baseline PR interval between the groups. However, the PR interval following admission in the aortic root abscess group (201 ± 66 ms) was significantly longer than the PR interval in both the aortic valve endocarditis (162 ± 27 ms) (24%, p = .009) and no endocarditis (143 ± 24 ms) (40%, p < .001) groups. The primary outcome measure, delta PR interval, was significantly longer in the ARA group (35 ± 51 ms) than no endocarditis (−5 ± 17 ms) (p = .001) and aortic valve endocarditis groups (0.2 ± 18) (p = .003).ConclusionsThe findings of our study support the notion that the PR interval is more likely to be prolonged in patients with ARA. Since ARA is associated with a high morbidity and mortality, PR interval prolongation in a patient with aortic valve endocarditis should prompt a thorough evaluation for aortic root involvement.     

Enhanced superoxide release and elevated protein kinase C activity in neutrophils from diabetic patients: association with periodontitis

Inflammation and oxidative stress are important factors in the pathogenesis of diabetes and contribute to the pathogenesis of diabetic complications. Periodontitis is an inflammatory disease that is characterized by increased oxidative stress, and the risk for periodontitis is increased significantly in diabetic subjects. In this study, we examined the superoxide (O(2)(-))-generating reduced nicotinamide adenine dinucleotide phosphate-oxidase complex and protein kinase C (PKC) activity in neutrophils. Fifty diabetic patients were grouped according to glycemic control and the severity of periodontitis. Neutrophils from diabetic patients with moderate [amount of glycated hemoglobin (HbA(1c)) between 7.0% and 8.0%] or poor (HbA(1c) >8.0%) glycemic control released significantly more O(2)(-) than neutrophils from diabetic patients with good glycemic control (HbA(1c) <7.0%) and neutrophils from nondiabetic, healthy individuals upon stimulation with 4beta-phorbol 12-myristate 13-acetate or N-formyl-Met-Leu-Phe. Depending on glycemic status, neutrophils from these patients also exhibited increased activity of the soluble- and membrane-bound forms of PKC, elevated amounts of diglyceride, and enhanced phosphorylation of p47-phox during cell stimulation. In addition, we report a significant correlation between glycemic control (HbA(1c) levels) and the severity of periodontitis in diabetic patients, suggesting that enhanced oxidative stress and increased inflammation exacerbate both diseases. Thus, hyperglycemia can lead to a novel form of neutrophil priming, where elevated PKC activity results in increased phosphorylation of p47-phox and O(2)(-) release.     

Pseudo-angiomatous hyperplasia of mammary stroma: a case with gigantomastia

Pseudo-angiomatous hyperplasia of mammary stroma (PASH) is a histopathological entity which is a microscopic fortuitous finding in mammary biopsies performed for different reasons. It may be symptomatic and appears then as a palpable lump. The term pseudo-angiomatous emphasizes the characteristic aspect of the stroma simulating a vascular tumor. We report a case of PASH in a 71 year-old woman who presented a recurring breast mass with rapid swelling of the mammary gland (70 x 60 x 20 cm) treated by mastectomy. PASH must be distinguished from a well-differentiated angiosarcoma. It is ruled out by immunohistochemistry.     

Endometrial atypical complex hyperplasia with extensive squamous metaplasia: two cases

We report two cases of endometrial atypical complex hyperplasia with an extensive squamous hyperplasia occurring in two women aged 48 and 31 years old. The histological study showed an increase in the gland to stroma ratio with a false crowding aspect due to an extensive area of squamous metaplasia; some metaplastic areas were centered by necrosis. There was glandular cytologic atypia. Histologic examination is necessary to confirm the diagnosis and to definitively rule out adenocarcinoma.     

Local prolactin is a target to prevent expansion of basal/stem cells in prostate tumors

Androgen-independent recurrence is the major limit of androgen ablation therapy for prostate cancer. Identification of alternative pathways promoting prostate tumor growth is thus needed. Stat5 has been recently shown to promote human prostate cancer cell survival/proliferation and to be associated with early prostate cancer recurrence. Stat5 is the main signaling pathway triggered by prolactin (PRL), a growth factor whose local production is also increased in high-grade prostate cancers. The first aim of this study was to use prostate-specific PRL transgenic mice to address the mechanisms by which local PRL induces prostate tumorogenesis. We report that (i) Stat5 is the major signaling cascade triggered by local PRL in the mouse dorsal prostate, (ii) this model recapitulates prostate tumorogenesis from precancer lesions to invasive carcinoma, and (iii) tumorogenesis involves dramatic accumulation and abnormal spreading of p63-positive basal cells, and of stem cell antigen-1–positive cells identified as a stem/progenitor-like subpopulation. Because basal epithelial stem cells are proposed to serve as tumor-initiating cells, we challenged the relevance of local PRL as a previously unexplored therapeutic target. Using a double-transgenic approach, we show that Δ1–9-G129R-hPRL, a competitive PRL-receptor antagonist, prevented early stages of prostate tumorogenesis by reducing or inhibiting Stat5 activation, cell proliferation, abnormal basal-cell pattern, and frequency or grade of intraepithelial neoplasia. This study identifies PRL receptor/Stat5 as a unique pathway, initiating prostate tumorogenesis by altering basal-/stem-like cell subpopulations, and strongly supports the importance of further developing strategies to target locally overexpressed PRL in human prostate cancer.     

Polarized expression of cystic fibrosis transmembrane conductance regulator and associated epithelial proteins during the regeneration of human airway surface epithelium in three-dimensional culture

We have previously shown that, in normal human airway tissue, localization of the cystic fibrosis transmembrane conductance regulator (CFTR) can be affected by epithelial maturation, polarity, and differentiation and that CFTR trafficking and apical localization depend on the integrity of the airway epithelium. In this study, we addressed the question of whether the three-dimensional (3-D) organization of adult human airway epithelial cells in suspension culture under rotation, leading to spheroid-like structures, could mimic the in vivo phenomenon of differentiation and polarization. The kinetics of the differentiation, polarity, and formation of the CFTR-ZO-1-ezrin complex was analyzed by transmission, scanning, and immunofluorescence microscopy. Functional activity of the airway surface epithelium was assessed by monitoring the degree of cAMP-stimulated chloride efflux from cultured cells. Our results show that after the initial step of dedifferentiation, characterized by a loss of ciliated cells and disappearance of epithelial subapical CFTR-ezrin-ZO-1 complex, the isolated cells formed 3-D spheroid structures within 24 hours. After 15 days, progressive ciliogenesis was observed and secretory cells could be identified. After 35 days of 3-D culture, ZO-1, CFTR, ezrin, and CD59 were apically or subapically located, and well-differentiated secretory and ciliated cells were identified. CFTR functionality was assessed by analyzing the Cl(-) secretion after amiloride and forskolin perfusion. After 35 days of culture of spheroids in suspension, a significant increase in Cl(-) efflux was observed in well-differentiated ciliated cells.