Highly conserved bifidobacteria in the human gut: Bifidobacterium longum subsp. longum as a potential modulator of elderly innate immunity

Aging is a physiological and immunological process involving the deterioration of human health, characterised by the progressive alteration of organs and their functions. The speed and extent of such decline are dependent on lifestyle, environment, and genetic factors. Moreover, with advancing age, humans become progressively more fragile and prone to acute and chronic diseases. Although the intestinal microbiota is predisposed to perturbations that accompany aging and frailty, it is generally accepted that the gut microbiota engages in multiple interactions that affect host health throughout the host life span. In the current study, an exhaustive in silico investigation of gut-associated bifidobacteria in healthy individuals from birth to old age revealed that Bifidobacterium longum subsp. longum is the most prevalent member, especially during infancy and in centenarians. Moreover, B. longum subsp. longum genome reconstruction and strain tracing among human gut microbiomes allowed the identification of prototypes of this taxon in the human gut microbiota of healthy elderly individuals. Such analyses guided culturomics attempts to isolate B. longum subsp. longum strains that matched the genomic content of B. longum subsp. longum prototypes from healthy elderly individuals. The molecular effects of selected B. longum subsp. longum strains on the human host were further investigated using in vitro microbe-host interactions, revealing differences in the host immune system transcriptome, with a reduction in gene expression of inflammation-related cytokines. These intriguing findings support the potential anti-aging effects of elderly associated prototypes of B. longum subsp. longum.

Transesophageal Echocardiography Guidance to Prevent and Manage Pitfalls from Abdominal Normothermic Regional Perfusion and Optimize Timing during Organ Retrieval from a Donor after Circulatory Death

An essential means of collecting more abdominal donor organs is controlled donation after circulatory death (cDCD). The organs are typically preserved during cDCD using the abdominal normothermic regional perfusion (A-NRP) technique to recirculate oxygenated blood flow following cardiac arrest and the withdrawal of life support. One of the challenges of A-NRP is ensuring the correct vascular devices' positionings, specifically extracorporeal membrane oxygenation cannulae and aortic balloons, typically achieved through fluoroscopy with or without contrast agents. Here, we present a case report in which transesophageal echocardiography (TEE) helped the transplant team to effectively procure viable abdominal organs from a cDCD donor in the shortest time frame, as minimizing time is one of the most crucial factors in maintaining organ viability. TEE use leads to a more effective and efficient A-NRP procedure with limited complications. In addition, it allows us to observe the circulation of both the thoracic and part of the abdominal organs using one fast exam. This case is the first report describing TEE as a primary guide and useful tool for DCD donors. However, prospective studies are needed to confirm that TEE could be used as standard practice during all DCD organ retrieval procedures.

The glutamate transporter excitatory amino acid carrier 1 associates with the actin-binding protein alpha-adducin

Excitatory amino acid carrier 1 (EAAC1) belongs to the family of the Na(+)-dependent glutamate carriers. Although the association between defective EAAC1 function and neurologic disease has been repeatedly studied, EAAC1 regulation is not yet fully understood. We have reported that in C6 glioma cells both the activity and membrane targeting of EAAC1 require the integrity of actin cytoskeleton. Here we show that, in the same model, EAAC1 partially co-localizes with actin filaments at the level of cell processes. Moreover, perinuclear spots in which EAAC1 co-localizes with the actin binding protein alpha-adducin are observed in some cells and, consistently, faint co-immunoprecipitation bands between EAAC1 and alpha-adducin are detected. Co-localization and partial co-immunoprecipitation of EAAC1 and adducin are still detectable after cell treatment with phorbol esters, a condition that leads to a protein kinase C (PKC)-dependent increase of EAAC1 expression on the membrane and to the phosphorylation of adducin. A co-immunoprecipitation band was also detected in protein extracts of rat hippocampus. The amount of adducin co-immunoprecipitated with EAAC1 increases after the treatment of C6 cells with retinoic acid, a differentiating agent that induces EAAC1 overexpression in this cell model. Moreover, in clones of C6 cells transfected with a hemagglutinin (HA)-tagged adducin, the bands of EAAC1 immunoprecipitated by an anti-HA antiserum were proportional to EAAC1 expression. These results suggest the existence of a pool of EAAC1 transporters associated with the actin binding protein alpha-adducin in a PKC-insensitive manner.

Airway barrier dysfunction induced by exposure to carbon nanotubes in vitro: which role for fiber length?

Although carbon nanotubes (CNTs) are increasingly used, their biological effects are only incompletely characterized. However, experimental evidence suggests that the intratracheal instillation of CNTs causes the formation of interstitial granulomas and progressive pulmonary fibrosis in rodents. Using human epithelial Calu-3 cells as a model of airway epithelium in vitro, we have recently reported that the exposure to commercial multi-walled CNTs (MWCNTs) causes a progressive decrease of the transepithelial electrical resistance (TEER), pointing to a CNT-dependent impairment of the epithelial barrier function. To characterize better this behavior, we compared the effects of two types of MWCNTs and single-walled CNTs (SWCNTs) of different lengths on the TEER of Calu-3 monolayers. All the materials were used at a dose of 100 microg/mL corresponding to an exposure of 73 microg/cm(2) of cell monolayer. Only the longer MWCNTs and SWCNTs cause a significant decrease in TEER. To elucidate the mechanism underlying the changes in barrier function, the expression of the junction proteins occludin and ZO-1 has been also assessed. No significant decrease in the mRNA for either protein is detectable after the exposure to any type of CNTs. It is concluded that the impairment of barrier function in Calu-3 monolayers is a peculiar effect of CNTs endowed with clear cut fiber properties and is not referable to marked changes in the expression of junction proteins.

C6 glioma cells differentiated by retinoic acid overexpress the glutamate transporter excitatory amino acid carrier 1 (EAAC1)

The transport of excitatory amino acids (EAA) in CNS is performed by a family of high affinity, sodium dependent carriers. One of these transporters, excitatory amino acid carrier 1 (EAAC1), is known to be regulated by several mechanisms that modify carrier abundance on the plasma membrane. Much less is known on EAAC1 regulation at the level of gene expression. Here we report that, in C6 rat glioma cells, a line recently described to contain neural stem-like cells, EAAC1 is markedly induced by all trans-retinoic acid (ATRA), a well known differentiating agent. Consistently, ATRA stimulates EAA transport, with the maximal effect observed at concentrations>or=1 microM. After 4 days of treatment with 10 microM ATRA, the transport Vmax is fivefold enhanced, Slc1a1 mRNA is increased by 400% compared with control, EAAC1 carrier is sixfold overexpressed and the C6 culture is greatly enriched of cells with bipolar morphology strongly positive for EAAC1 immunoreactivity. Compared with untreated cells, ATRA-treated C6 cells express less Slc1a3 mRNA, for the transporter GLAST, but significantly higher levels of Slc1a2 mRNA, for the transporter GLT-1, although no expression of either protein is detected with Western blot in both untreated and ATRA-treated cells. Consistently, the inhibition pattern of aspartate transport and its stimulation by phorbol esters are indicative of a transport process due to EAAC1 operation. Under the conditions adopted, ATRA treatment causes the induction of proteolipid protein, an oligodendrocytic marker. These results indicate that, in C6 cells, ATRA stimulates the expression of EAAC1, possibly as a step toward oligodendrocytic differentiation, and constitute the first demonstration of the induction of this transporter by a differentiating agent.

[The ATLS Courses in Italy. Twelve years experience]

ATLS Courses were introduced in the USA in 1980 and have been taught in Italy since 1994. Through theoretical lessons and practical sessions, their scope is to provide proper training for doctors with every kind of speciality who work in Emergency Departments, in order to prepare them to rapidly and effectively intervene on a patient who has suffered a serious trauma. Universities, in fact, do not prepare doctors adequately on this topic, while the application of the ATLS method in the first hours after trauma can effectively improve the prognosis of the patient. This study collects the data of the Italian experience in ATLS training, which has been carried out under the aegis of the Italian Chapter of the American College of Surgeons. The ATLS Courses have become widespread throughout our Country, which today is the fourth in the world for number of courses held every year.

The inhibition of glutamine synthetase sensitizes human sarcoma cells to L-asparaginase

PURPOSE

To evaluate the activity of the antitumor enzyme L: -asparaginase (ASNase) on tumor cells of mesenchymal origin and the contribution of glutamine synthetase (GS) to the adaptation to the metabolic stress caused by the anti-tumor enzyme.

METHODS

We studied the effects of ASNase in six human sarcoma cell lines: HT1080 (fibrosarcoma); RD (rhabdomyosarcoma); SW872 (liposarcoma); HOS, SAOS-2, and U2OS (osteosarcoma) in the absence or in the presence of the GS inhibitor methionine L: -sulfoximine (MSO).

RESULTS

HT1080 and SW872 cells were highly sensitive to ASNase-dependent cytotoxicity. In contrast, RD, SAOS-2, HOS, and U2OS cells exhibited only a partial growth suppression upon treatment with the anti-tumor enzyme. In these cell lines ASNase treatment was associated with increased levels of GS. When ASNase was used together with MSO, the proliferation of the poorly sensitive cell lines was completely blocked and a significant decrease in the IC(50) for ASNase was observed. Moreover, when ASNase treatment was carried on in the presence of MSO, HOS and U2OS osteosarcoma cells exhibited a marked cytotoxicity, with increased apoptosis.

CONCLUSIONS

In human sarcoma cells (1) GS markedly contributes to the metabolic adaptation of tumor cells to ASNase and (2) the inhibition of GS activity enhances the antiproliferative and cytotoxic effects of ASNase. The two-step interference with glutamine metabolism, obtained through the combined treatment with ASNase and MSO, may provide a novel therapeutic approach that should be further investigated in human tumors of mesenchymal origin.

Chlorpromazine, clozapine and olanzapine inhibit anionic amino acid transport in cultured human fibroblasts

We report here that chlorpromazine, a first generation antipsychotic drug, inhibits anionic amino acid transport mediated by system X(-) (AG) (EAAT transporters) in cultured human fibroblasts. With 30 microM chlorpromazine, transport inhibition is detectable after 3 h of treatment, maximal after 48 h (>60%), and referable to a decrease in V(max). Chlorpromazine effect is not dependent upon changes of membrane potential and is selective for system X(-) (AG) since transport systems A and y(+) are not affected. Among antipsychotic drugs, the inhibitory effect of chlorpromazine is shared by two dibenzodiazepines, clozapine and olanzapine, while other compounds, such as risperidon, zuclopentixol, sertindol and haloperidol, are not effective. Transport inhibition by clozapine and olanzapine, but not by chlorpromazine, is reversible, suggesting that the mechanisms involved are distinct. These results indicate that a subset of antipsychotic drugs inhibits EAAT transporters in non-nervous tissues and prompt further investigation on possible alterations of glutamate transport in peripheral tissues of schizophrenic patients.

Cloning and characterization of a senescence inducing and class II tumor suppressor gene in ovarian carcinoma at chromosome region 6q27

Cytogenetic, molecular and functional analysis has shown that chromosome region 6q27 harbors a senescence inducing gene and a tumor suppressor gene involved in several solid and hematologic malignancies. We have cloned at 6q27 and characterized the RNASE6PL gene which belongs to a family of cytoplasmic RNases highly conserved from plants, to man. Analysis of 55 primary ovarian tumors and several ovarian tumor cell lines indicated that the RNASE6PL gene is not mutated in tumor tissues, but its expression is significantly reduced in 30% of primary ovarian tumors and in 75% of ovarian tumor cell lines. The promoter region of the gene was unaffected in tumors cell lines. Transfection of RNASE6PL cDNA into HEY4 and SG10G ovarian tumor cell lines suppressed tumorigenicity in nude mice. When tumors were induced by RNASE6PL-transfected cells, they completely lacked expression of RNASE6PL cDNA. Tumorigenicity was suppressed also in RNASE6PL-transfected pRPcT1/H6cl2T cells, derived from a human/mouse monochromosomic hybrid carrying a human chromosome 6 deleted at 6q27. Moreover, 63.6% of HEY4 clones and 42.8% of the clones of XP12ROSV, a Xeroderma pigmentosum SV40-immortalized cell line, transfected with RNASE6PL cDNA, developed a marked senescence process during in vitro growth. We therefore propose that RNASE6PL may be a candidate for the 6q27 senescence inducing and class II tumor suppressor gene in ovarian cancer.