The stability and activity of human neuroserpin are modulated by a salt bridge that stabilises the reactive centre loop

Neuroserpin (NS) is an inhibitory protein belonging to the serpin family and involved in several pathologies, including the dementia Familial Encephalopathy with Neuroserpin Inclusion Bodies (FENIB), a genetic neurodegenerative disease caused by accumulation of NS polymers. Our Molecular Dynamics simulations revealed the formation of a persistent salt bridge between Glu289 on strand s2C and Arg362 on the Reactive Centre Loop (RCL), a region important for the inhibitory activity of NS. Here, we validated this structural feature by simulating the Glu289Ala mutant, where the salt bridge is not present. Further, MD predictions were tested in vitro by purifying recombinant Glu289Ala NS from E. coli. The thermal and chemical stability along with the polymerisation propensity of both Wild Type and Glu289Ala NS were characterised by circular dichroism, emission spectroscopy and non-denaturant gel electrophoresis, respectively. The activity of both variants against the main target protease, tissue-type plasminogen activator (tPA), was assessed by SDS-PAGE and chromogenic kinetic assay. Our results showed that deletion of the salt bridge leads to a moderate but clear reduction of the overall protein stability and activity

Pharmacophore modelling as useful tool in the lead compounds identification and optimization

The goal of computer-aided molecular design methods in modern medicinal chemistry is to reduce the overall cost and time associated to the discovery and development of a new drug by identifying the most promising candidates to focus the experimental efforts on. Very often, many drug discovery projects have reached already a well-advanced stage before detailed structural data on the protein target have become available. A possible consequence is that often, medicinal chemists develop novel compounds for a target using preliminary structure–activity information, together with the theoretical models of interactions. Only responses that are consistent with the working hypothesis contribute to an evolution of the used models. Within this framework, the pharmacophore approach has proven to be successful, allowing the perception and understanding of key interactions between a receptor and a ligand[1]. In recent years, our research group exploited this useful modeling tool with the aim to identify new chemical entities and/or optimizing known lead compounds to obtain more active drugs in the field of antitumor, antiviral, and antibacterial drugs. In this communication, we present an overview of our recent works in which we used the pharmacophore modelling approach combined with induced fit docking, 3D-QSAR approach, and HTVS for the analysis of drug-receptor interactions and the discovery of new inhibitors of IKKβ, Bcl-xl, and c-kit tyrosine kinase, all targets involved into the initiation and the development of different types of cancer[2-5]

Chronic, nonspecific, postinfectious, retroperitoneal fibrosis and ureteral obstruction

ABSTRACT Introduction: Two cases of severe ureteral obstruction following nonspecific, postinfectious, chronic retroperitoneal fibrosis are described, which both originated by a primitive intestinal pathology. Patients: This complication was observed in two women: first, 65 years old, submitted for ulcerative colitis to a total proctocolectomy, with ileo-pouch-anal anastomosis, complicated by an anastomotic fistula; and second, 66 years old, operated with an extended left hemicolectomy, for an adenocarcinoma of the recto-sigmoid colon complicated with a vaginal fistula. In these cases, computerized tomography demonstrated a unilateral hydronephrosis, secondary to a complete obstruction of the ureter; a subsequent nephro-ureterectomy became necessary. Histology demonstrated nonspecific inflammatory lesions. Discussions: Postinfectious, chronic inflammation of the retroperitoneum acts on the ureteral and peri-ureteral tissues, inducing an inflammatory and then a fibrotic process. Conclusions: We underline the opportunity of a precocious and radical treatment of every retroperitoneal infection. Keywords: Intestinal fistula, Retroperitoneal fibrosis, Retroperitoneal infection, Ureteral obstructionINTRODUCTION: Two cases of severe ureteral obstruction following nonspecific, postinfectious, chronic retroperitoneal fibrosis are described, which both originated by a primitive intestinal pathology. PATIENTS: This complication was observed in two women: first, 65 years old, submitted for ulcerative colitis to a total proctocolectomy, with ileo-pouch-anal anastomosis, complicated by an anastomotic fistula; and second, 66 years old, operated with an extended left hemicolectomy, for an adenocarcinoma of the recto-sigmoid colon complicated with a vaginal fistula. In these cases, computerized tomography demonstrated a unilateral hydronephrosis, secondary to a complete obstruction of the ureter; a subsequent nephro-ureterectomy became necessary. Histology demonstrated nonspecific inflammatory lesions. DISCUSSIONS: Postinfectious, chronic inflammation of the retroperitoneum acts on the ureteral and peri-ureteral tissues, inducing an inflammatory and then a fibrotic process. CONCLUSIONS: We underline the opportunity of a precocious and radical treatment of every retroperitoneal infection

Food Matrix Effects of Polyphenol Bioaccessibility from Almond Skin during Simulated Human Digestion

The goal of the present study was to quantify the rate and extent of polyphenols released in the gastrointestinal tract (GIT) from natural (NS) and blanched (BS) almond skins. A dynamic gastric model of digestion which provides a realistic simulation of the human stomach was used. In order to establish the effect of a food matrix on polyphenols bioaccessibility, NS and BS were either digested in water (WT) or incorporated into home-made biscuits (HB), crisp-bread (CB) and full-fat milk (FM). Phenolic acids were the most bioaccessible class (68.5% release from NS and 64.7% from BS). WT increased the release of flavan-3-ols (p < 0.05) and flavonols (p < 0.05) from NS after gastric plus duodenal digestion, whereas CB and HB were better vehicles for BS. FM lowered the % recovery of polyphenols, the free total phenols and the antioxidant status in the digestion medium, indicating that phenolic compounds could bind protein present in the food matrix. The release of bioactives from almond skins could explain the beneficial effects associated with almond consumption

Effect of green tea catechins in patients with high-grade prostatic intraepithelial neoplasia: Results of a short-term double-blind placebo controlled phase II clinical trial

Background and study objective: Several studies suggest a protective role of green tea catechins against prostate cancer (PCa). In order to evaluate the efficacy of green tea catechins for chemoprevention of PCa in patients with high-grade prostate intraepithelial neoplasia (HG-PIN) we performed a phase II clinical trial. Methods: Sixty volunteers with HG-PIN were enrolled to carry out a double-blind randomized placebo-controlled phase II clinical trial. Treated group took daily 600 mg of green tea catechins (Categ Plus®) for 1 year. Patients were screened at 6 and 12 months through prostatic biopsy and measurements of prostate-specific antigen (PSA). Results: Despite the statistically significant reduction of PSA observed in subjects who received green tea catechins for 6 and 12 months, we did not find any statistical difference in PCa incidence between the experimental groups neither after 6 nor after 12 months. However, throughout the one-year follow-up we observed very limited adverse effects induced by green tea catechins and a not significant improvement in lower urinary tract symptoms and quality of life. Conclusions: Although the small number of patients enrolled in our study and the relatively short duration of intervention, our findings seems to deny the efficacy of green tea catechins. However, results of our clinical study, mainly for its low statistical strength, suggest that the effectiveness of green tea catechins should be evaluated in both a larger cohort of men and longer trial

Management and therapeutic response of a prostate ductal adenocarcinoma: a still unknown tumour?

Ductal adenocarcinoma is a rare subtype of prostate cancer with a worse prognosis.Histologically, it is characterized by the presence of tall, pseudostratified columnar epithelium with abundant cytoplasm organized in a papillary or cribriform-papillary pattern. Several clinical differences distinguish this subtype of prostate cancer by the conventional acinar adenocarcinoma: exophytic growth into the prostatic urethra, different clinical presentation, different sites of metastasis and more aggressiveness. The rarity of this tumour forced to base our knowledge on small case series or on individual case reports, and does not help to establish appropriate guidelines. Therefore, the diagnosis of this tumour masks clinical implications that are still not well-understood.We report the case of a 69-year-old Caucasian man with a diagnosis of pure prostate ductal adenocarcinoma that early developed multiple metastases after radical prostatectomy. The patient started hormonal therapy with a fast biochemical and radiologic (positron emission tomography-computed tomography, PET-CT) hormonal escape. Therefore, we took the decision to perform chemotherapy with Taxotere along with prednisolone with a relative stability of prostate-specific antigen (PSA) level, but a new PET-CT scan showed a further progression of the disease. Finally, the patient underwent therapy with Abiraterone acetate that did not stop the cancer progression.No therapeutic options available showed a good control of disease progression. PSA proved to be a poor marker while, on the contrary, PET-CT scan has proved to be particularly useful in the management of the disease progression. More efforts are required to add new knowledge about this tumour and assess what is known until now