AMPK/HuR-Driven IL-20 Post-Transcriptional Regulation in Psoriatic Skin.

IL-20 is involved in the development of skin psoriasis. The molecular mechanisms underlying IL-20 overexpression in psoriatic epidermis remain to be elucidated. We showed that IL-20 was primarily upregulated in psoriatic skin at the post-transcriptional level. The RNA-binding protein HuR relocalized to the cytoplasm of keratinocytes (KCs) of psoriatic patients, suggesting that it stabilizes numerous transcripts, as observed in the human KC cell lines used to assess IL-20 mRNA. We characterized epidermal HuR RNA targets in psoriatic skin using ribonucleoprotein immunoprecipitation analyzed via high-throughput sequencing. Numerous transcripts that are upregulated in psoriasis were targeted by HuR, supporting the participation of HuR in pathogenic processes such as morphological changes, innate and adaptive immune responses, and metabolic inflammatory responses. Finally, we identified the metabolic sensor AMP-activated protein kinase (AMPK) as being responsible for HuR cytoplasmic relocalization because its activity was severely impaired in human psoriatic epidermis, and in vivo drug-mediated AMPK inhibition in mouse epidermis promoted HuR cytoplasmic localization, IL-20 overproduction, acanthosis, and hyperkeratosis. These results provide insights into the molecular links between metabolism and post-transcriptional networks during chronic inflammation.

Clinical use of p-proteasome in discriminating metastatic melanoma patients: comparative study with LDH, MIA and S100B protein.

Plasmatic proteasome (p-proteasome) has recently been described as a new marker for metastatic melanoma. The objective of this study was to compare the diagnostic and prognostic values of p-proteasome with three other melanoma serological markers: S100B protein, melanoma inhibitory activity protein (MIA) and lactate dehydrogenase (LDH) in the plasma of 121 stage I-IV melanoma patients. Laboratory analyses were performed by standardized ELISA (p-proteasome, MIA), immunoluminometric assay (S100B) and colorimetry (LDH). We found that all markers were relevant for discriminating metastatic from nonmetastatic patients but p-proteasome displayed the highest diagnostic accuracy. P-proteasome and S100B were the most sensitive (58.1%) and p-proteasome and MIA the most specific (98.7 and 100%) in detecting metastatic disease. P-proteasome and S100B had the highest area under receiver operating characteristics curve, 0.811 (95% CI: 0.725-0.897) and 0.822 (95% CI: 0.738-0.906), respectively. These two markers were the best in detecting patients with lymph node metastases. S100B, MIA and LDH diagnostic accuracy was increased when these markers were combined with p-proteasome. As shown with univariate analysis, shorter progression-free and overall survival rates were significantly associated with elevated plasma levels of each markers. The multivariate Cox regression analysis identified p-proteasome as the only independent predictor of a poorer progression-free survival (p = 0.030). In conclusion, this comparative study established that p-proteasome quantification in combination with other melanoma biomarkers is an attractive approach for the biological follow-up of melanoma patients.

Nested high-resolution melting curve analysis a highly sensitive, reliable, and simple method for detection of JAK2 exon 12 mutations--clinical relevance in the monitoring of polycythemia.

JAK2 exon 12 mutations are found in myeloproliferative disorders characterized by erythrocytosis. Lying in a 33-bp region and conserving the open reading frame, they often present a low allelic burden (<10%), which excludes screening with techniques such as allele-specific PCR or different sequencing protocols. High-resolution melting (HRM), a fast in-tube method, seems the most accurate routine technique for that. We describe a reliable and powerful nested HRM technique, independent of DNA preparation and with technical sensitivity of 100% (95% CI, 93% to 100%) and specificity of 96.7% (95% CI, 89.7% to 96.7%). Screening a cohort of 10 idiopathic erythrocytosis, 28 polycythemia vera, and 7 secondary erythrocytosis cases allowed the detection of 15 mutants, including 9 different mutations, of which 3 were unreported, all in the polycythemia vera group, and presented a characteristic profile: pure erythrocytosis associated with low serum erythropoietin. Threshold detection level ranged from 1% to 3% allelic burden, depending on the mutation. All of the HRM positive signals were found mutated by sequencing. Six of them (40%), however, required cloning before sequencing, because of low allelic burden. Classic techniques such as genomic sequencing may therefore miss patients with mutations. Given its sensitivity, HRM (and nested HRM) can be used in routine diagnosis and seems to be the most efficient of current techniques for detection of JAK2 exon 12 mutations.

Acute administration of l-arginine restores nitric oxide-mediated relaxation in isolated pulmonary arteries from pulmonary hypertensive exercise trained rats.

Hypoxia-induced pulmonary hypertension is associated with an impairment of nitric oxide-mediated vasorelaxation in the pulmonary circulation that is not prevented by exercise training. The present study was designed to test the hypothesis that a decrease in l-arginine bioavailability could be involved in this blunted response to exercise training. Male Wistar rats were randomly assigned to 4 groups: normotensive sedentary, normotensive trained, pulmonary hypertensive sedentary, pulmonary hypertensive trained. Pulmonary hypertension was induced by chronic exposure to hypobaric hypoxia (PIO(2) approximately 90 mmHg). Endothelium-dependent vasorelaxation to acetylcholine (10(-8)-10(-4) M) with or without l-arginine (10(-3) M) and/or nitro-l-arginine methyl ester (5.10(-6) M) was assessed on isolated pulmonary arterial rings. Maximal relaxation to acetylcholine was impaired in both pulmonary hypertensive groups. Acute l-arginine supplementation improved acetylcholine-induced vasorelaxation in the pulmonary hypertensive trained rats (P<0.01), to the level obtained in the normotensive sedentary ones, but not in the pulmonary hypertensive sedentary rats. This improvement was abolished when nitro-l-arginine methyl ester was added to the organ bath and was accounted for by an increase in eNOS protein content. These results confirm that the potential beneficial effect of exercise on nitric oxide-mediated pulmonary artery vasorelaxation is partly blunted by deleterious effects of hypoxia on l-arginine bioavailability. Further studies are needed to evaluate the benefit of the combination of exercise training and l-arginine supplementation for the treatment of pulmonary hypertension.

In vitro degradation and in vivo biocompatibility of poly(lactic acid) mesh for soft tissue reinforcement in vaginal surgery.

This study was aimed at evaluating the in vitro degradation, the in vivo biocompatibility and at comparing the effects of two methods of sterilization on poly(L-lactic acid) (PLA(94)) resorbable mesh. The mesh was manufactured to be used as surgical soft tissue reinforcement in the vaginal area. Samples of 100 mg of PLA(94) mesh (10 x 10 mm(2)) were immersed in isoosmolar 0.13M, pH 7.4 phosphate buffer solution at 37 degrees C, during 12 months. The hydrolytic degradation up to 12 months after immersion was monitored by measuring weight loss, mesh area changes, and by various analytical techniques namely Differential scanning calorimetry (DSC), capillary zone electrophoresis (CZE), size exclusion chromatography (SEC), and environmental scanning electron microscopy (ESEM). Specimens of nonsterilized, ethylene-oxide (ETO) sterilized, and gamma-ray sterilized PLA(94) mesh were compared. Fifteen samples were implanted in an incisional hernia Wistar rat model. Histopathology was performed up to 90 days after implantation to evaluate the inflammatory response and the collagen deposition. Although the decrease of molecular weight due to polymer chain scissions started 6 weeks after in vitro immersion, water-soluble degradation products and decrease of tensile strength appeared after 8 months only. Analyses showed also that ETO sterilization did not affect the degradation of the PLA(94) mesh. In contrast, gamma-ray sterilization increased very much the sensitivity of the mesh to the hydrolytic degradation. In vivo, the PLA(94) mesh exhibited good biocompatibility over the investigated time period.

Long-lasting bioresorbable poly(lactic acid) (PLA94) mesh: a new approach for soft tissue reinforcement based on an experimental pilot study.

The purpose of this study was to evaluate host response and soft-tissue regeneration after poly(lactic acid) (PLA) mesh implantation in a rat model, in comparison with light-weight polypropylene (PPL) and poly(glycolic acid) (PGA) meshes. Full-thickness abdominal wall defects were created in 45 Wistar rats and reconstructed with 15 PLA(94), 15 PPL and 15 PGA meshes. Animals were killed on days 7, 30 and 90 to evaluate the presence of adhesions and changes in tensile strength of the implants. Histopathology and immunohistochemistry were performed to evaluate the collagen deposition and the inflammatory response. Statistics were done using unpaired Student's t-test, Mann-Whitney rank sum test, Student-Newman-Keuls test and Bonferroni (Dunn) t-test. The inflammatory response induced by the PLA mesh implantation was significantly milder than after PPL mesh. In PLA, vascularity and collagen organization was significantly higher than in PPL and PGA at 30 and 90 days, and collagen composition score was significantly higher than in PPL at 7 and 30 days. In PLA, shrinkage was significantly lower than in PPL and PGA at 7 and 30 days. Elongation at break and tensile strength were comparable between PLA and PPL over the 90-day period. The PLA mesh induces a milder inflammatory response, more orderly collagen deposition than PPL, and preserved comparable tensile strength after 90 days.

Long-term alpha interferon treatment is effective on anaemia and significantly reduces iron overload in congenital dyserythropoiesis type I.

Interferon has been shown to be an effective treatment of congenital dyserythropoiesis type I (CDA-I), but the optimal dose and the feasibility of this treatment remains to be determined. Here, in a 9-yr follow-up of a single patient, we show that interferon remains active during such a long period. The optimal dose of conventional alpha interferon could be evaluated at 2 million units twice a week. Pegylated interferon could be used as well at a dose of 30 microg/wk. During interferon treatment, serum and erythrocyte ferritin levels decreased progressively, and remained inversely correlated with haemoglobin levels. On repeated liver biopsies, iron overload could be normalized. Low dose interferon is a long-term treatment of CDA-I, and allows a significant decrease in iron overload, that could be interesting even in patients who are only moderately anaemic.