ADAM12 localizes with c-Src to actin-rich structures at the cell periphery and regulates Src kinase activity

ADAM12 is an active metalloprotease playing an important role in tumour progression. Human ADAM12 exists in two splice variants: a long transmembrane form, ADAM12-L, and a secreted form, ADAM12-S. The subcellular localization of ADAM12-L is tightly regulated and involves intracellular interaction partners and signalling proteins. We demonstrate here a c-Src-dependent redistribution of ADAM12-L from perinuclear areas to actin-rich Src-positive structures at the cell periphery, and identified two separate c-Src binding sites in the cytoplasmic tail of ADAM12-L that interact with the SH3 domain of c-Src with different binding affinities. The association between ADAM12-L and c-Src is transient, but greatly stabilized when the c-Src kinase activity is disrupted. In agreement with this observation, kinase-active forms of c-Src induce ADAM12-L tyrosine phosphorylation. Interestingly, ADAM12-L was also found to enhance Src kinase activity in response to external signals, such as integrin engagement. Thus, we suggest that activated c-Src binds, phosphorylates, and redistributes ADAM12-L to specific sites at the cell periphery, which may in turn promote signalling mechanisms regulating cellular processes with importance in cancer.     

Inositide signaling in the nucleus: From physiology to pathology

A inositide-dependent signaling exists in the nucleus. In this review we focused to the nuclear PI-PLC signaling activity, its downstream effects and its role in haematological malignancies. PI-PLC β1 is involved in the physiological control of the cell cycle and by acting on the Cylin D3 promoter plays a crucial role in the process of C2C12 myoblast differentiation. In hematological malignancies recent studies showed that PI-PLC β1 mono-allelic deletion correlates with a higher risk of AML evolution. Moreover it has been shown that PI-PLC β1 promoter is hypermethylated in high-risk MDS patients and that the amount of PI-PLC β1 mRNA could predict the clinical response to azacitidine, a well known demethylating drug.All in all the data reviewed here pave the way to a new prognostic and therapeutic strategy in some haematological malignancies.     

Paleoparasitologic, paleogenetic and paleobotanic analysis of XVIII century coprolites from the church La Concepción in Santa Cruz de Tenerife, Canary Islands, Spain

We present the results of a paleoparasitologic, paleogenetic and paleobotanic analysis of coprolites recovered during the excavation of the church La Concepción in Santa Cruz de Tenerife. Coprolites (n = 4) were rehydrated and a multidisciplinary analysis was conducted. The paleobotanic analysis showed numerous silicates, seeds and fruits of the family Moraceae. In the paleoparasitologic study, Ascaris sp. eggs (n = 344) were identified. The paleogenetic results confirmed the Ascaris sp. infection as well as the European origin of human remains. These findings contribute to our knowledge of ancient helminthes infections and are the first paleoparasitological record of Ascaris sp. infection in Spain.     

A T-cell-selective interleukin 2 mutein exhibits potent antitumor activity and is well tolerated in vivo

Human interleukin 2 (IL-2; Proleukin) is an approved therapeutic for advanced-stage metastatic cancer; however, its use is restricted because of severe systemic toxicity. Its function as a central mediator of T-cell activation may contribute to its efficacy for cancer therapy. However, activation of natural killer (NK) cells by therapeutically administered IL-2 may mediate toxicity. Here we have used targeted mutagenesis of human IL-2 to generate a mutein with approximately 3,000-fold in vitro selectivity for T cells over NK cells relative to wild-type IL-2. We compared the variant, termed BAY 50-4798, with human IL-2 (Proleukin) in a therapeutic dosing regimen in chimpanzees, and found that although the T-cell mobilization and activation properties of BAY 50-4798 were comparable to human IL-2, BAY 50-4798 was better tolerated in the chimpanzee. BAY 50-4798 was also shown to inhibit metastasis in a mouse tumor model. These results indicate that BAY 50-4798 may exhibit a greater therapeutic index than IL-2 in humans in the treatment of cancer and AIDS.     

Nonresonant confocal Raman imaging of DNA and protein distribution in apoptotic cells

Nonresonant confocal Raman imaging has been used to map the DNA and the protein distributions in individual single human cells. The images are obtained on an improved homebuilt confocal Raman microscope. After statistical analysis, using singular value decomposition, the Raman images are reconstructed from the spectra covering the fingerprint region. The data are obtained at a step interval of approximately 250 nm and cover a field from 8- to 15- micro m square in size. Dwell times at each pixel are between 0.5 and 2 s, depending on the nature and the state of the cell under investigation. High quality nonresonant Raman images can only be obtained under these conditions using continuous wave high laser powers between 60 and 120 mW. We will present evidence that these laser powers can still safely be used to recover the chemical distributions in fixed cells. The developed Raman imaging method is used to image directly, i.e., without prior labeling, the nucleotide condensation and the protein distribution in the so-called nuclear fragments of apoptotic HeLa cells. In the control (nonapoptotic) HeLa cells, we show, for the first time by Raman microspectroscopy, the presence of the RNA in a cell nucleus.     

Production and purification of statins from Aspergillus terreus strains

Lovastatin, mevastatin, pravastatin and monacolin J were produced using Aspergillus terreus strains. Mevastatin (170 mg/l) was obtained at 14 days from the A1 strain, lovastatin (256 mg/l) at 21 days from the A2 strain and pravastatin (270-300 mg/l) at 14 days from both the A1 and A2 strains grown on defatted soybean flour. Similar yields of monacolin J (5-10 mg/l) were detected for both strains. Fermentation carried out by adding glycerol to A1 7-d old cultures gave 244 mg lovastatin/l at 14 days employing whole soybean flour. A new extraction procedure was applied to an A2 19-d old culture on the mycelium and the culture filtrate separately. Recovery yield showed that 83% lovastatin was associated with the mycelium and 17% was free in the culture filtrate. © Rapid Science Ltd. 1998     

Prenatal Stress Produces Social Behavior Deficits and Alters the Number of Oxytocin and Vasopressin Neurons in Adult Rats

The present study investigated the long-lasting effects of prenatal repeated restraint stress on social behavior and anxiety, as well as its repercussions on oxytocin (OT) and vasopressin (VP)-positive neurons of the paraventricular (PVN) and supraoptic (SON) nuclei from stressed pups in adulthood. Female Wistar rats were exposed to restraint stress in the last 7 days of pregnancy. At birth, pups were cross-fostered and assigned to the following groups: prenatally non-stressed offspring raised by prenatally non-stressed mothers (NS:NS), prenatally non-stressed offspring raised by prenatally stressed mothers (S:NS), prenatally stressed offspring raised by prenatally non-stressed mothers (NS:S), prenatally stressed offspring raised by prenatally stressed mothers (S:S). As adults, male prenatally stressed offspring raised both by stressed mothers (S:S group) and non-stressed ones (NS:S group) showed impaired social memory and interaction. In addition, when both adverse conditions coexisted (S:S group), increased anxiety-like behavior and aggressiveness was observed in association with a decrease in the number of OT-positive magnocellular neurons, VP-positive magnocellular and parvocellular neurons of the PVN. The NS:S group exhibited a reduction in the amount of VP-positive magnocellular neurons compared to the S:NS. Thus, the social behavior deficits observed in the S:S and NS:S groups may be only partially associated with these alterations to the peptidergic systems. No changes were shown in the OT and VP cellular composition of the SON nucleus. Nevertheless, it is clear that a special attention should be given to the gestational period, since stressful events during this time may be related to the emergence of behavioral impairments in adulthood.     

Eicosapentaenoic acid inhibits tumour necrosis factor-α-induced lipolysis in murine cultured adipocytes

Eicosapentaenoic acid (EPA) is an omega-3 polyunsaturated fatty acid with beneficial effects in obesity and insulin resistance. High levels of proinflammatory cytokine tumour necrosis factor-α (TNF-α) in obesity promote lipolysis in adipocytes, leading to the development of insulin resistance. Thus, the aims of the present study were to analyze the potential antilipolytic properties of EPA on cytokine-induced lipolysis and to investigate the possible mechanisms involved. The EPA effects on basal and TNF-α-induced lipolysis were determined in both primary rat and 3T3-L1 adipocytes. Treatment of primary rat adipocytes with EPA (100 and 200 μM) significantly decreased basal glycerol release (P<.01) and prevented cytokine-induced lipolysis in a dose-dependent manner (P<.001). Moreover, EPA decreased TNF-α-induced activation of nuclear factor-κB and extracellular-related kinase 1/2 phosphorylation. In addition, the antilipolytic action of EPA was stimulated by the AMP-kinase (AMPK) activator 5-aminoimidazole-4-carboxamide-1-b-d-ribofuranoside and blocked by the AMPK-inhibitor compound C. Moreover, we found that EPA stimulated hormone-sensitive lipase (HSL) phosphorylation on serine-565, which further supports the involvement of AMPK in EPA's antilipolytic actions. Eicosapentaenoic acid treatment (24 h), alone and in the presence of TNF-α,? also decreased adipose triglyceride lipase (ATGL) protein content in cultured adipocytes. However, oral supplementation with EPA for 35 days was able to partially reverse the down-regulation of HSL and ATGL messenger RNA observed in retroperitoneal adipose tissue of high-fat-diet-fed rats. These findings suggest that EPA inhibits proinflammatory cytokine-induced lipolysis in adipocytes. This effect might contribute to explain the insulin-sensitizing properties of EPA.