Role of surface-exposed loops of Haemophilus influenzae protein P2 in the mitogen-activated protein kinase cascade

The outer membrane of gram-negative bacteria contains several proteins, and some of these proteins, the porins, have numerous biological functions in the interaction with the host; porins are involved in the activation of signal transduction pathways and, in particular, in the activation of the Raf/MEK1-MEK2/mitogen-activated protein kinase (MAPK) cascade. The P2 porin is the most abundant outer membrane protein of Haemophilus influenzae type b. A three-dimensional structural model for P2 was constructed based on the crystal structures of Klebsiella pneumoniae OmpK36 and Escherichia coli PhoE and OmpF. The protein was readily assembled into the beta-barrel fold characteristic of porins, despite the low sequence identity with the template proteins. The model provides information on the structural features of P2 and insights relevant for prediction of domains corresponding to surface-exposed loops, which could be involved in the activation of signal transduction pathways. To identify the role of surface-exposed loops, a set of synthetic peptides were synthesized according to the proposed model and were assayed for MEK1-MEK2/MAPK pathway activation. Our results show that synthetic peptides corresponding to surface loops of protein P2 are able to activate the MEK1-MEK2/MAPK pathways like the entire protein, while peptides modeled on internal beta strands are unable to induce significant phosphorylation of the MEK1-MEK2/MAPK pathways. In particular, the peptides corresponding to loops L5 (Lys206 to Gly219), L6B (Ser239 to Lys253), and L7 (Thr280 to Lys287) activate, as the whole protein, essentially JNK and p38.     

Resting ECG is modified after oophorectomy and regresses with estrogen replacement therapy in premenopausal women

OBJECTIVE: To assess the effects of bilateral oophorectomy on the resting ECG and whether they regress with estrogen replacement therapy. STUDY DESIGN: Twenty-six premenopausal and 15 postmenopausal women were enrolled in the present study. All women had undergone hysterectomy and bilateral ovariectomy. All women underwent 12-lead ECG on admission to hospital. A second ECG was recorded 20-25 days after surgery. After this second ECG, premenopausal women were randomly divided into two groups. The women of Group A (n=14) received transdermal ethinyl estradiol (EE). The women of Group B (n=12) did not receive any therapy. A third ECG was performed in both groups 30-35 days after randomization. RESULTS: Bilateral oophorectomy did not induce any significant modifications in the ECG parameters of the postmenopausal women whereas in the premenopausal women, we observed a significant increment in mean duration of the T wave, a significant decrease in its amplitude and significant reduction in ST depression in V2, V3, V4 and V5. The third ECG showed regression of the ECG modifications in Group A. In the women of Group B, the second and third ECGs were not substantially different, but there were statistically significant differences between the first and third ECGs. CONCLUSIONS: The results of the present study show that ovariectomy induces significant though not clinically evident modifications in resting ECG. These ECG changes are probably due to the sudden reduction in sex hormone plasma levels after ovariectomy. Administration of estradiol induced regression of the ECG modifications.     

Porins from Salmonella enterica serovar Typhimurium activate the transcription factors activating protein 1 and NF-kappaB through the Raf-1-mitogen-activated protein kinase cascade.

In this study we examined the ability of Salmonella enterica serovar Typhimurium porins to activate activating protein 1 (AP-1) and nuclear factor kappaB (NF-kappaB) through the mitogen-activated protein kinase (MAPK) cascade, and we identified the AP-1-induced protein subunits. Our results demonstrate that these enzymes may participate in cell signaling pathways leading to AP-1 and NF-kappaB activation following porin stimulation of cells. Raf-1 was phosphorylated in response to the treatment of U937 cells with porins; moreover, the porin-mediated increase in Raf-1 phosphorylation is accompanied by the phosphorylation of MAPK kinase 1/2 (MEK1/2), p38, extracellular-signal-regulated kinase 1/2, and c-Jun N-terminal kinase. We used three different inhibitors of phosphorylation pathways: 2'-amino-3'-methoxyflavone (PD-098059), a selective inhibitor of MEK1 activator and the MAPK cascade; 4-(4-fluorophenyl)-2-(4-methylsulfinylphenyl)-5-(4-pyridyl)1H-imidazole (SB203580), a specific inhibitor of the p38 pathway; and 7beta-acetoxy-1alpha,6beta,9alpha-trihydroxy-8,13-epoxy-labd-14-en-11-one (forskolin), an inhibitor at the level of Raf-1 kinase. PD-098059 pretreatment of cells decreases AP-1 and NF-kappaB activation by lipopolysaccharide (LPS) but not by porins, and SB203580 pretreatment of cells decreases mainly AP-1 and NF-kappaB activation by porins; in contrast, forskolin pretreatment of cells does not affect AP-1 and NF-kappaB activation following either porin or LPS stimulation. Our data suggest that the p38 signaling pathway mainly regulates AP-1 and NF-kappaB activation in cells treated with S. enterica serovar Typhimurium porins. Antibody electrophoretic mobility shift assays showed that JunD and c-Fos binding is found in cells treated with porins, in cells treated with LPS, and in unstimulated cells. However, by 30 to 60 min of stimulation, a different complex including c-Jun appears in cells treated with porins or LPS, while the Fra-2 subunit is present only after porin stimulation. These data suggest different molecular mechanisms of activation induced by porins or by LPS.     

The Role of Optical Coherence Tomography in Clarifying the Mechanisms for Dobutamine Stress Echocardiography‐Induced Takotsubo Cardiomyopathy

Takotsubo cardiomyopathy is a clinical disorder characterized by a transient dilatation and akynesis or dyskinesis of the left ventricular (LV) apex, mimicking an anterior wall acute myocardial infarction in the absence of significant coronary artery disease (CAD). It typically occurs during an episode of severe emotional or physical stress. Recent reports suggested the potential of dobutamine stress echocardiography (DSE) in inducing the aforementioned syndrome. The transient dysfunction of the LV does not fit any known coronary distribution. Furthermore, there is no obstructive CAD demonstrated at angiography to account for the observed dysfunction. Consequently, the pathophysiology of this syndrome is still undetermined. Here, we report a case of DSE‐induced Takotsubo cardiomyopathy in which high‐resolution intracoronary imaging was utilized to exclude possible vessel alterations to help provide potential mechanistic explanations for the development of this condition.     

Instrumental,clinical and subjective evaluation of the efficacy of a cosmetic treatment for home use

Background: In the last few years, there has been increasing demand for aesthetic procedures to improve the effects of skin aging.

Aim: To evaluate the anti-aging efficacy, tolerability and skin changes induced by the topical products containing hyaluronic acid, N-acetyl glucosamine and gamma-amino butyric acid through instrumental techniques, clinical and subjective evaluation.

Patients/Method: Twenty female enrolled applied a day and night cream after applying a serum, once week applied a mask, for 2 months. A clinical assessment of smoothness, expression wrinkles, fine wrinkles and measurements of the parameters using Reveal Imager, X-Rite, Corneometer, Dermalab, Moisture Meter EpiD were taken at day 0, 15, 30 and 60 of study period. A final assessment questionnaire was submitted.

Results: The products were accepted by all the volunteers. The hydration (Corneometer: T0 49.17 vs T60 61.11, average variation 24.28%) (Moisture Meter EpiD: T0 45.73 vs T60 61.10, average variation 33.60%), elasticity (Dermalab: T0 56.06 vs T60 62.78, average variation 11.98%) and lightening of the skin (X-Rite: T0 60.23 vs T60 63.36, average variation 5.26%) improved. All changes were statistically significant (p < 0.05).

Conclusion: The efficacy of the topical products is confirmed by subjective, clinical and instrumental assessment. This should be a routine approach in dermatologic practice.     

Left ventricular longitudinal systolic dysfunction is an independent marker of cardiovascular risk in patients with hypertension

BackgroundTo explore the prognostic value of left ventricular (LV) longitudinal systolic dysfunction in patients with hypertension.MethodsIn 156 hypertensive subjects, LV longitudinal systolic function was assessed by echocardiographic measurement of M-mode left atrioventricular plane displacement (AVPD) and Tissue Doppler (TD)-derived mitral annulus peak systolic velocity (S(m)). Patients were followed for development of the following cardiovascular events: congestive heart failure requiring hospitalization, new-onset angina, nonfatal myocardial infarction, coronary revascularization procedures, transient ischemic attack, nonfatal stroke, and cardiovascular death.ResultsOver a follow-up of 23.3 +/- 5.4 months, 24 patients had 29 events. Both longitudinal systolic indices were predictive of outcome (hazard ratios: AVPD, 0.24, P < 0.001; S(m), 0.22; P < 0.001). AVPD 相似文献   

NCOA4-mediated ferritinophagy in macrophages is crucial to sustain erythropoiesis in mice

Nuclear receptor coactivator 4 (NCOA4) promotes ferritin degradation and Ncoa4-ko mice in a C57BL/6 background show microcytosis and mild anemia, aggravated by iron deficiency. To understand tissue-specific contributions of NCOA4-mediated ferritinophagy we explored the effect of Ncoa4 genetic ablation in the iron-rich Sv129/J strain. Increased body iron content protects these mice from anemia and, in basal conditions, Sv129/J Ncoa4-ko mice show only microcytosis; nevertheless, when fed a low-iron diet they develop a more severe anemia compared to that of wild-type animals. Reciprocal bone marrow (BM) transplantation from wild-type donors into Ncoa4-ko and from Ncoa4-ko into wild-type mice revealed that microcytosis and susceptibility to iron deficiency anemia depend on BM-derived cells. Reconstitution of erythropoiesis with normalization of red blood count and hemoglobin concentration occurred at the same rate in transplanted animals independently of the genotype. Importantly, NCOA4 loss did not affect terminal erythropoiesis in iron deficiency, both in total and specific BM Ncoa4-ko animals compared to controls. On the contrary, upon a low iron diet, spleen from wild-type animals with Ncoa4-ko BM displayed marked iron retention compared to (wild-type BM) controls, indicating defective macrophage iron release in the former. Thus, erythropoietin administration failed to mobilize iron from stores in Ncoa4-ko animals. Furthermore, Ncoa4 inactivation in thalassemic mice did not worsen the hematologic phenotype. Overall our data reveal a major role for NCOA4-mediated ferritinophagy in macrophages to favor iron release for erythropoiesis, especially in iron deficiency.     

Speckle tracking echocardiography in heart failure development and progression in patients with apneas

Heart Failure Reviews - Obstructive (OA) and central apneas (CA) are highly prevalent breathing disorders that have a negative impact on cardiac structure and function; while OA promote the...     

A novel MEIS2 mutation explains the complex phenotype in a boy with a typical NF1 microdeletion syndrome

Concurrence of distinct genetic conditions in the same patient is not rare. Several cases involving neurofibromatosis type 1 (NF1) have recently been reported, indicating the need for more extensive molecular analysis when phenotypic features cannot be explained by a single gene mutation. Here, we describe the clinical presentation of a boy with a typical NF1 microdeletion syndrome complicated by cleft palate and other dysmorphic features, hypoplasia of corpus callosum, and partial bicoronal craniosynostosis caused by a novel 2bp deletion in exon 2 of Meis homeobox 2 gene (MEIS2) inherited from the mildly affected father. This is only the second case of an inherited MEIS2 intragenic mutation reported to date. MEIS2 is known to be associated with cleft palate, intellectual disability, heart defects, and dysmorphic features. Our clinical report suggests that this gene may also have a role in cranial morphogenesis in humans, as previously observed in animal models.