HIF-1α/MMP-9 Axis Is Required in the Early Phases of Skeletal Myoblast Differentiation under Normoxia Condition In Vitro

Hypoxia-inducible factor (HIF)-1α represents an oxygen-sensitive subunit of HIF transcriptional factor, which is usually degraded in normoxia and stabilized in hypoxia to regulate several target gene expressions. Nevertheless, in the skeletal muscle satellite stem cells (SCs), an oxygen level-independent regulation of HIF-1α has been observed. Although HIF-1α has been highlighted as a SC function regulator, its spatio-temporal expression and role during myogenic progression remain controversial. Herein, using biomolecular, biochemical, morphological and electrophysiological analyses, we analyzed HIF-1α expression, localization and role in differentiating murine C2C12 myoblasts and SCs under normoxia. In addition, we evaluated the role of matrix metalloproteinase (MMP)-9 as an HIF-1α effector, considering that MMP-9 is involved in myogenesis and is an HIF-1α target in different cell types. HIF-1α expression increased after 24/48 h of differentiating culture and tended to decline after 72 h/5 days. Committed and proliferating mononuclear myoblasts exhibited nuclear HIF-1α expression. Differently, the more differentiated elongated and parallel-aligned cells, which are likely ready to fuse with each other, show a mainly cytoplasmic localization of the factor. Multinucleated myotubes displayed both nuclear and cytoplasmic HIF-1α expression. The MMP-9 and MyoD (myogenic activation marker) expression synchronized with that of HIF-1α, increasing after 24 h of differentiation. By means of silencing HIF-1α and MMP-9 by short-interfering RNA and MMP-9 pharmacological inhibition, this study unraveled MMP-9's role as an HIF-1α downstream effector and the fact that the HIF-1α/MMP-9 axis is essential in morpho-functional cell myogenic commitment.

Adiponectin Modulates Smooth Muscle Cell Morpho-Functional Properties in Murine Gastric Fundus via Sphingosine Kinase 2 Activation

Adipokines are peptide hormones produced by the adipose tissue involved in several biological functions. Among adipokines, adiponectin (ADPN) has antidiabetic and anti-inflammatory properties. It can also modulate food intake at central and peripheral levels, acting on hypothalamus and facilitating gastric relaxation. ADPN exerts its action interacting with two distinct membrane receptors and triggering some well-defined signaling cascades. The ceramidase activity of ADPN receptor has been reported in many tissues: it converts ceramide into sphingosine. In turn, sphingosine kinase (SK) phosphorylates it into sphingosine-1 phosphate (S1P), a crucial mediator of many cellular processes including contractility. Using a multidisciplinary approach that combined biochemical, electrophysiological and morphological investigations, we explored for the first time the possible role of S1P metabolism in mediating ADPN effects on the murine gastric fundus muscle layer. By using a specific pharmacological inhibitor of SK2, we showed that ADPN affects smooth muscle cell membrane properties and contractile machinery via SK2 activation in gastric fundus, adding a piece of knowledge to the action mechanisms of this hormone. These findings help to identify ADPN and its receptors as new therapeutic targets or as possible prognostic markers for diseases with altered energy balance and for pathologies with fat mass content alterations.

Defining the Molecular Mechanisms of the Relaxant Action of Adiponectin on Murine Gastric Fundus Smooth Muscle: Potential Translational Perspectives on Eating Disorder Management

Adiponectin (ADPN), a hormone produced by adipose tissue, facilitates gastric relaxation and can be a satiety signal in the network connecting peripheral organs and the central nervous system for feeding behavior control. Here, we performed preclinical research by morpho-functional analyses on murine gastric fundus smooth muscle to add insights into the molecular mechanisms underpinning ADPN action. Moreover, we conducted a clinical study to evaluate the potential use of ADPN as a biomarker for eating disorders (ED) based on the demonstrated gastric alterations and hormone level fluctuations that are often associated with ED. The clinical study recruited patients with ED and healthy controls who underwent blood draws for ADPN dosage and psychopathology evaluation tests. The findings of this basic research support the ADPN relaxant action, as indicated by the smooth muscle cell membrane pro-relaxant effects, with mild modifications of contractile apparatus and slight inhibitory effects on gap junctions. All of these actions engaged the ADPN/nitric oxide/guanylate cyclase pathway. The clinical data failed to unravel a correlation between ADPN levels and the considered ED, thus negating the potential use of ADPN as a valid biomarker for ED management for the moment. Nevertheless, this adipokine can modulate physiological eating behavior, and its effects deserve further investigation.

Canine leishmaniasis surveillance in a northern Italy kennel

An epidemiological survey on canine leishmaniasis (CanL) was performed during a 3-year period (2007-2009) in a public kennel of the Bologna province. The presence of the disease was shown in the canine population for the first time in 2007 by indirect fluorescent antibody test (IFAT). The parasite circulation was confirmed also by direct diagnostic tools, as PCR, cytology and cultural method, performed on different bioptic materials. The parasite was isolated and identified as Leishmania infantum zymodeme MON 1. The serological monitoring was performed also in 2008 and 2009 on animals that previously showed negative or uncertain results. The incidence values calculated by significant seroconversions in IFAT titre ≥ 1/160, ranged between 4.9% and 6.6%, indicating a stable focus of leishmaniasis. The entomological survey, performed by sticky and CO(2)-baited traps in 2008, showed the presence of the vector Phlebotomus perfiliewi. This study allowed us to identify a stable focus of CanL in an area that was not considered eco-compatible with the presence of the vector and infection. Our results confirm the northward spread of CanL towards areas not previously affected by autochthonous foci.

[Primary malignant tumors of the spleen]

A case of angiosarcoma of the spleen is examined. In a review of reports in the literature of primary malignant tumours of the spleen, the extreme variety of this neoplasia and the lack of any precise classification are underlined.

[Treatment protocol for duodenal ulcers. Outlines of indications for surgery]

105 duodenal ulcer patients were examined over a two-year period. Apart from anamnesis, endoscopy and radiology, a personal treatment protocol was used to assess the indications for medical or surgical treatment. Endoscopy undeniably plays a central role in identifying the characteristics of the ulcer and its complications and will indicate medical treatment for the majority of duodenal ulcers though it also serves to confirm or modify the indication for surgery.

[Treatment of gastric cancer in the aged]

The A. suggest a modification of Stojanovick primary technique in the treatment of gastric cancer in the elderly. They reviewed pathology of gastric resected patients with exclusion of duodenal transit and they foretell such a technique because of a quicker performance, the scantiness of post-operative complication and, at the end, the complete lack of malabsorption syndromes which are so frequent in gastric resected patients.

[Simple cholecystectomy without drainage. A dilemma?]

A retrospective study was carried out to show the uselessness of the routine employment of the drainage after simple cholecystectomy. 1425 patients underwent cholecystectomy because for cholelithiasis; of these 164 (13%) were drained because of adhesions, concomitant pancreatitis, inadvertent damage, empiema, gangrena and perforation of the gallbladder. In no case of the 1261 patients without drainage it has been possible to demonstrate the presence of one of those complications for which the use of a drainage after simple cholecystectomy is commonly advised.

[Early factors of necrosis in acute hemorrhagic necrotic pancreatitis]

In 60 cases of acute pancreatitis it was noted that 10 developed towards the haemorrhagic necrotic form. All these cases were surgically verified. Stress is laid on the factors that appear earliest in the change-over from an oedematous to a necrotico-haemorrhagic form. These factors (shock, fever, leukocytosis, hypocalcaemia, hyperglycaemia, pain, etc.) are assessed in relation to the frequency of their appearance and of their importance and reliability. These parameters point to the change-over from a pancreatopathy of medical significance to one of surgical interest and also suggest the most suitable moment for carrying out the operation.

[Retroperitoneal rupture of the duodenum caused by closed abdominal injury]

Preoperative diagnosis of retroperitoneal rupture of the duodenum is very difficult. Radiographical observation of air surrounding the right kidney or psoas muscle is of great assistance in this respect, but may only be expected in 30% of cases. Examination of the first segment of the digestive tract with the aid of "gastropgrafin" is advised. With the abdomen open, the presence of air, haematoma or bile in the transverse mesocolon or mesentery of the small intestine may be noted. In most cases, the breach can be closed with a double layer, leaving a drainage tube in the retroperitoneum. Measures than can be taken when suturing is unfeasable are also described.