Restoration of senescent human diploid fibroblasts by modulation of the extracellular matrix

Human diploid fibroblasts have the capacity to complete a finite number of cell divisions before entering a state of replicative senescence characterized by growth arrest, changes in morphology, and altered gene expression. Herein, we report that interaction with extracellular matrix (ECM) from young cells is sufficient to restore aged, senescent cells to an apparently youthful state. The identity of the restored cells as having been derived from senescent cells has been confirmed by a variety of methods, including time lapse live cell imaging and DNA finger print analysis. In addition to cell morphology, phenotypic restoration was assessed by resumption of proliferative potential, growth factor responsiveness, reduction of intracellular reactive oxygen species levels, recovery of mitochondrial membrane potential, and increased telomere length. Mechanistically, we find that both Ku and SIRT1 are induced during restoration and are required for senescent cells to return to a youthful phenotype. These observations demonstrate that human cellular senescence is profoundly influenced by cues from the ECM, and that senescent cell plasticity is much greater than that was previously believed to be the case.

Malondialdehyde inhibits an AMPK-mediated nuclear translocation and repression activity of ALDH2 in transcription

Aging process results from deleterious damages by reactive oxygen species, in particular, various metabolic aldehydes. Aldehyde dehydrogenase 2 (ALDH2) is one of metabolic enzymes detoxifying various aldehydes under oxidative conditions. AMP-activated protein kinase (AMPK) plays a key role in controlling metabolic process. However, little was known about the relationship of ALDH2 with AMPK under oxidative conditions. Here, we, by using MDA-specific monoclonal antibody, screened the tissues of young and old rats for MDA-modified proteins and identified an ALDH2 as a prominent MDA-modified protein band in the old rat kidney tissue. ALDH2 associates with AMPK and is phosphorylated by AMPK. In addition, AICAR, an activator of AMP-activated protein kinase, induces the nuclear translocation of ALDH2. ALDH2 in nucleus is involved in general transcription repression by association with histone deacetylases. Furthermore, MDA modification inhibited the translocation of ALDH2 and the association with AMPK, and ultimately led to de-repression of transcription in the reporter system analysis. In this study, we have demonstrated that ALDH2 acts as a transcriptional repressor in response to AMPK activation, and MDA modifies ALDH2 and inhibits repressive activity of ALDH2 in general transcription. We thus suggest that increasing amount of MDA during aging process may interrupt the nuclear function of ALDH2, modulated by AMPK.

Antimicrobial activity of the constituents of Smallanthus sonchifolius leaves against methicillin-resistant Staphylococcus aureus

BACKGROUND AND OBJECTIVES

Methicillin-resistant Staphylococcus aureus (MRSA) has been a serious problem as its infection is associated with higher mortality and increase cost worldwide. In the present study, the antibacterial activity of enhydrin, polymatin B, allo-schkuhriolide from the leaves of Smallanthus sonchifolius was investigated.

MATERIAL AND METHODS

Enhydrin, polymatin B, allo-schkuhriolide from the leaves of Smallanthus sonchifolius were tested for antimicrobial activity using micro dilution broth method against 2 strains of ATCC 33591, ATCC 25923 and 15 strains of clinical isolates MRSA.

RESULTS

The antibacterial activity of Smallanthus sonchifolius can safely be attributed to enhydrin as polymatin B, and allo-schkuhriolide are not showing any activity against Staphylococcus aureus strains. The enhydrin showed good antibacterial activity against all tested strains (MIC = 125-500 microg/ml).

DISCUSSION

These results suggest that only enhydrin can be considered as an antibacterial drug against MRSA.

Effect of probiotic-, bacteriophage-, or organic acid-supplemented feeds or fermented soybean meal on the growth performance, acute-phase response, and bacterial shedding of grower pigs challenged with Salmonella enterica serotype Typhimurium

A 28-d experiment evaluated the growth performance, acute-phase response, and bacterial shedding patterns in pigs (n = 108; initially, 38.7 ± 6.7 kg) fed 6 treatment diets, including a control diet with no antimicrobial agents (CON), a positive control diet containing chlortetracycline, 100 mg/kg (CT), a diet containing anti-Salmonella Typhimurium bacteriophage, 3 × 10(9) plaque-forming units/kg of feed (ASB), Lactobacillus plantarum CJLP56, 6.5 × 10(8) cfu/kg of feed (LP), 0.2% microencapsulated organic acids (MOA), or 5% fermented soybean meal (FSM). Pigs were fed the diets for 2 wk before and 2 wk after challenging orally with Salmonella enterica serotype Typhimurium (SalT). Before bacterial challenge, ADFI was similar in all groups. After SalT challenge, ADFI of CON pigs was less (P < 0.05) than all other groups. Before challenge, pigs on MOA, FSM, and CT diets had greater (P < 0.05) ADG and G:F than CON pigs. After challenge (wk 3 to 4) and during the overall experimental period (wk 1 to 4), ADG of all treatment groups and G:F of all treatment groups except the LP group were greater (P < 0.05) than those of CON pigs. Relative to all other treatments, CON and LP pigs had greater (P < 0.05) bacterial shedding scores on d 7 after SalT challenge. At d 14 postchallenge, shedding scores declined (P < 0.05) in all treatment groups compared with CON pigs. Serum haptoglobin for all treatment groups increased from d 0 concentrations on d 6 postchallenge and declined to prechallenge concentrations on d 13 (P < 0.05). Circulating IGF-I concentrations declined from 2 to 6 d postchallenge and increased again by d 13 in ASB and LP groups, did not decline in FSM and CT groups, and continuously declined through d 13 in CON and LP groups (P < 0.05). However, in MOA group, IGF-I concentrations declined from preinfection concentrations on d 2, increased on d 4, and declined again until d 13 (P < 0.05). The serum concentrations of the cytokines IL-6 and IL-1β were not generally affected by SalT challenge. In conclusion, acute infection of growing pigs with SalT was associated with short-term febrile responses in most pigs and reductions in ADFI and ADG of CON pigs. Compared with the CON diet, ASB, FSM, and MOA diets had a similar benefit to the antibiotic-supplemented diet in improving the performance of growing pigs, especially after bacterial challenge. However, further work needs to be done to better understand their mode of action in this class of pigs.

Ultrasound-stimulated peripheral nerve regeneration within asymmetrically porous PLGA/Pluronic F127 nerve guide conduit

Recently, we developed a novel method to fabricate a nerve guide conduit (NGC) with asymmetrical pore structure and hydrophilicity using poly(lactic-co-glycolic acid) (PLGA) and Pluronic F127 by a modified immersion precipitation method. From the animal study using a rat model (sciatic nerve defect of rat), we recognized that the unique PLGA/Pluronic F127 tube provided good environments for nerve regeneration. In this study, we applied low-intensity pulsed ultrasound as a simple and noninvasive stimulus at the PLGA/F127 NGC-implanted site transcutaneously in rats to investigate the feasibility of ultrasound for the enhanced nerve regeneration through the tube. The nerve regeneration behaviors within the ultrasound-stimulated PLGA/Pluronic F127 NGCs were compared with the NGCs without the ultrasound treatment as well as normal nerve by histological and immunohistochemical observations. It was observed that the PLGA/Pluronic F127 tube-implanted group applied with the ultrasound had more rapid nerve regeneration behavior (approximately 0.71 mm/day) than the tube-implanted group without the ultrasound treatment (approximately 0.48 mm/day). The ultrasound-treated tube group also showed greater neural tissue area as well as larger axon diameter and thicker myelin sheath than the tube group without the ultrasound treatment, indicating better nerve regeneration. The better nerve regeneration behavior in the our NGC/ultrasound system may be caused by the synergistic effect of the asymmetrically porous PLGA/Pluronic F127 tube with unique properties (selective permeability, hydrophilicity, and structural stability, which can provide good environment for nerve regeneration) and physical stimulus (stimulation of the Schwann cells and activation of the neurotrophic factors).

Suppression of ROS generation by 4,4-diaminodiphenylsulfone in non-phagocytic human diploid fibroblasts

The action mode of 4,4-diaminodiphenylsulfone (DDS) is still under debate, although it has long been used in treatment of several dermatologic diseases including Hansens disease. In this study, we tested the effect of DDS as an antioxidant on paraquat-induced oxidative stress in non-phagocytic human diploid fibroblasts (HDFs). Overall, preincubation of HDFs with DDS prevented the oxidative stress and the resulting cytotoxic damages caused by paraquat in these cells. The specific effects of DDS in paraquat-treated HDFs are summarized as follows: a) reducing the expression of NADPH oxidase 4 (NOX4) by inhibiting paraquat-induced activation of PKC; b) inhibiting paraquat-induced decreases in mitochondrial complex protein levels as well as in membrane potentials; c) consequently, inhibiting the generation of cytosolic and mitochondrial superoxide anions. Taken together, these findings suggest that DDS would suppress the radical generation in non-phagocytic HDFs during oxidative stress, and that DDS might have the extended potential to be used further in prevention of other oxidative stress-related pathologies.

Reduction of Nup107 attenuates the growth factor signaling in the senescent cells

Hypo-responsiveness to growth factors is a fundamental feature of cellular senescence. In this study, we found markedly decreased level of Nup107, a key scaffold protein in nuclear pore complex assembly, in senescent human diploid fibroblasts as well as in organs of aged mice. Depletion of Nup107 by specific siRNA in young human diploid fibroblasts prevented the effective nuclear translocation of phosphorylated extracellular signal-regulated kinase (ERK) following epidermal growth factor (EGF) stimulation, and decreased the expression of c-Fos in consequence. The disturbances in ERK signaling in Nup107 depleted cells closely mirror the similar changes in senescent cells. Knockdown of Nup107 in anaplastic oligodendroglioma cells caused cell death, rather than growth retardation, indicating a greater sensitivity to Nup107 depletion in cancer cells than in normal cells. These findings support the notion that Nup107 may contribute significantly to the regulation of cell fate in aged and transformed cells by modulating nuclear trafficking of signal molecules.

Modulation of insulin sensitivity and caveolin-1 expression by orchidectomy in a nonobese type 2 diabetes animal model

Previously, we found that male JYD mice developed type 2 diabetes but female mice did not, and that decreased expression levels of caveolin-1 were correlated with the development of a diabetic phenotype in these mice. Therefore, we hypothesized that sex hormones affect the expression of caveolin-1 and contribute to the development of insulin resistance and hyperglycemia in JYD mice. We used glucose and insulin tolerance tests to examine insulin sensitivity in male, female and orchidectomized male JYD mice. Glucose uptake was analyzed by using (18)F-fluorodeoxyglucose positron emission tomography. We also examined insulin-signaling molecules and caveolin proteins in various tissues in these mice by Western blotting. In addition, we examined changes of caveolin-1 expression in L6 skeletal muscle cells treated with 17-β estradiol or dihydroxytestosterone. We found that glucose and insulin tolerance were impaired and hyperglycemia developed in male, but not female, JYD mice. Expression of insulin-signaling molecules such as insulin receptor, protein kinase B, and glucose transporter-4 were decreased in male JYD mice compared with female mice. Orchidectomized JYD male mice showed improved glucose and insulin tolerance with a concomitant increase in the expression of insulin-signaling molecules and caveolin-1 in adipose tissue and skeletal muscle. Moreover, 17-β-estradiol treatment increased the expression of caveolin-1 in differentiated skeletal muscle cells. We conclude that sex hormones modulate the expression of caveolin-1 and insulin-signaling molecules, subsequently affecting insulin sensitivity and the development of type 2 diabetes in JYD mice.

Caveolin-1 as a novel indicator of wound-healing capacity in aged human corneal epithelium

Excess caveolin-1 has been reported to play a role in age-dependent hyporesponsiveness to growth factors in vitro. Therefore, we hypothesized that caveolin-1-dependent hyporesponsiveness to growth factors in aged corneal epithelial cells might be responsible for delayed wound healing in vivo. To test this hypothesis, we evaluated corneal wound-healing time by vital staining using fluorescein after laser epithelial keratomileusis (LASEK). We compared wound-healing times in young, middle-aged and elderly patients. We also examined caveolin-1 levels and other aging markers, such as p53 and p21, in the corneal epithelium. Elderly patients generally had higher caveolin-1 levels in the corneal epithelia than young patients. There were, however, variations among individuals with increased caveolin-1 in some young patients and decreased levels in some elderly patients. Wound-healing time after LASEK correlated well with the corneal caveolin-1 status. Therefore, we suggest that caveolin-1 status might be responsible for delayed wound healing in elderly patients after LASEK. Caveolin-1 status might be a regulator for wound-healing capacity and a novel target for in vivo adjustment.

Dietary source of vitamin B(12) intake and vitamin B(12) status in female elderly Koreans aged 85 and older living in rural area

Recently, we found and analyzed vitamin B₁₂ in some Korean traditional plant foods which had not reported, yet. This study was to investigate vitamin B₁₂ intake and its dietary sources and the vitamin B₁₂ status in the very old elderly Koreans. We measured serum vitamin B₁₂ level and estimated the amounts of vitamin B₁₂ intake from different dietary sources in female elderly Koreans aged 85 and over who had consumed a relatively low animal traditional diet for the whole life. The average age of the subjects (n = 127) was 98.0 years (85-108 years). The assessment on energy and nutrient intake involved a one-day 24-hour recall, and serum vitamin B₁₂ concentration was measured by radioimmunoassay. Overall diet pattern was not different between the 85-99 yr-old group and centenarians, except centenarians were taking more dairy product. The average ratio of plant food to animal food consumption was 87.5:12.5 in weight. The average vitamin B₁₂ intake of our subjects was 3.2 µg/day, and 52.7% of subjects consumed under estimated average requirement, 2.0 µg/day. On dietary source, 67.3% of dietary vitamin B₁₂ was from meat, eggs and fishes and 30.6% was from plant foods, such as soybean-fermented foods, seaweeds, and kimchi. The average serum vitamin B₁₂ concentration was 450.5 pg/mL, and low serum vitamin B₁₂ (< 200 pg/mL) was found in 9.6% of subjects. Dietary vitamin B₁₂ intake was significantly lower in subjects with low serum vitamin B₁₂ (0.79 µg/day) than those with normal serum vitamin B₁₂ (3.47 µg/day). There were no significant difference in vitamin B₁₂ intake and its dietary sources and serum vitamin B₁₂ level between the 85-99 yr-old group and centenarians. In conclusion, several plant-origin foods including seaweed, soybean-fermented foods, and kimchi, may contribute significantly to good vitamin B₁₂ status in very old elderly Koreans.

Activation of AMP-activated protein kinase stimulates the nuclear localization of glyceraldehyde 3-phosphate dehydrogenase in human diploid fibroblasts

In addition to its well-known glycolytic activity, GAPDH displays multiple functions, such as nuclear RNA export, DNA replication and repair, and apoptotic cell death. This functional diversity depends on its intracellular localization. In this study, we explored the signal transduction pathways involved in the nuclear translocation of GAPDH using confocal laser scanning microscopy of immunostained human diploid fibroblasts (HDFs). GAPDH was present mainly in the cytoplasm when cultured with 10% FBS. Serum depletion by culturing cells in a serum-free medium (SFM) led to a gradual accumulation of GAPDH in the nucleus, and this nuclear accumulation was reversed by the re-addition of serum or growth factors, such as PDGF and lysophosphatidic acid. The nuclear export induced by the re-addition of serum or growth factors was prevented by LY 294002 and SH-5, inhibitors of phosphoinositide 3-kinase (PI3K) and Akt/protein kinase B, respectively, suggesting an involvement of the PI3K signaling pathway in the nuclear export of GAPDH. In addition, 5-aminoimidazole-4-carboxamide-1-beta-D-ribofuranoside (AICAR), an activator of AMP-activated protein kinase (AMPK), stimulated the nuclear translocation of GAPDH and prevented serum- and growth factor-induced GAPDH export. AMPK inhibition by compound C or AMPK depletion by siRNA treatment partially prevented SFM- and AICAR-induced nuclear translocation of GAPDH. Our data suggest that the nuclear translocation of GAPDH might be regulated by the PI3K signaling pathway acting mainly as a nuclear export signal and the AMPK signaling pathway acting as a nuclear import signal.

Caveolae-mediated entry of Salmonella typhimurium into senescent nonphagocytotic host cells

Elderly individuals have an increased susceptibility to microbial infections because of age-related anatomical, physiological, and environmental factors. However, the mechanism of aging-dependent susceptibility to infection is not fully understood. Here, we found that caveolae-dependent endocytosis is elevated in senescent cells. Thus, we focused on the implications of caveolae-dependent endocytosis using Salmonella typhimurium, which causes a variety of diseases in humans and animals by invading the eukaryotic host cell. Salmonella invasion increased in nonphagocytotic senescent host cells in which caveolin-1 was also increased. When caveolae structures were disrupted by methyl-β-cyclodextrin or siRNA of caveolin-1 in the senescent cells, Salmonellae invasion was reduced markedly compared to that in nonsenescent cells. In contrast, the over-expression of caveolin-1 led to increased Salmonellae invasion in nonsenescent cells. Moreover, in aged mice, caveolin-1 was found to be highly expressed in Peyer’s patch and spleen, which are targets for infection by Salmonellae. These results suggest that high levels of caveolae and caveolin-1 in senescent host cells might be related to the increased susceptibility of elderly individuals to microbial infections.

Candidate gene polymorphisms for diabetes mellitus, cardiovascular disease and cancer are associated with longevity in Koreans

Long-lived people may have a unique genetic makeup that makes them more resistant than the general population to prevalent age-related diseases; however, not much is known about genes involved in the longevity. To identify susceptibility variants controlling longevity, we performed a high-throughput candidate gene study using 137 Koreans over 90 yr old and 213 young healthy Koreans. We evaluated 463 informative markers located in 176 candidate genes mostly for diabetes mellitus, cardiovascular disease and cancer under five genetic models. We estimated the odds ratios for each allele, genotype, haplotype, and gene-gene interaction using logistic regression analysis. Associations between 13 genes and longevity were detected at a P-value less than 0.01. Particularly, the rs671 (A) allele of the aldehyde dehydrogenase 2 family (mitochondrial) (ALDH2) gene was associated with longevity only in men (OR 2.11, P =0.008). Four genes, proprotein convertase subtilisin/kexin type 1 (PCSK1, P=0.008), epidermal growth factor receptor (EGFR, P=0.003), paired box 4 (PAX4, P=0.008), and V-yes-1 Yamaguchi sarcoma viral related oncogene homolog (LYN, P=0.002) consistently yielded statistical evidence for association with longevity. The findings of the current study may provide a starting point for future studies to unravel genetic factors controlling longevity in Koreans.

Water dropwort (Ostericum sieboldii) and Sedum (Sedum sarmentosum) delay H(2)O(2)-induced senescence in human diploid fibroblasts

It is known that a close relationship exists among oxidative damage, senescence, and aging. Water dropwort (Ostericum sieboldii Miq. Nakai) and Sedum (Sedum sarmentosum Bunge) are popular green vegetables in Korea and are reported to have strong antioxidative activity. We investigated whether dropwort and Sedum have the potential to prevent aging using H(2)O(2)-induced prematurely senescent human diploid fibroblasts (HDFs). Dropwort and Sedum had similarly high contents of polyphenols, but dropwort had a flavonoid content about twofold higher than that of Sedum. Exposure of young HDFs to H(2)O(2) induced G2/M cell cycle arrest, positive senescence-associated (SA) beta-galactosidase (beta-gal) staining, and elevated p53, p21, and p16 protein levels. However, cotreatment with dropwort or Sedum ethanol extract significantly lowered p53, p21, and p16 levels and intracellular reactive oxygen species levels and attenuated the cell cycle arrest compared with H(2)O(2)-alone treatment. Interestingly, the increase in p16 level was prevented more quickly and clearly by dropwort treatment than Sedum treatment. The number of SA beta-gal-positive cells at 7 days after treatment was significantly reduced in dropwort-treated cells compared to H(2)O(2) alone-treated cells, whereas it was slightly reduced in Sedum-treated cells with no significance. In conclusion, dropwort showed a potential anti-senescence activity in H(2)O(2)-treated HDFs, which might be mediated by reducing p16, p21, and p53 levels and oxidative stress.

Caveolae-mediated entry of Salmonella typhimurium in a human M-cell model

Intestinal M cells in Peyer's patches, the specialized antigen-sampling cells of the mucosal immune system, are exploited by Salmonella and other pathogens as a route of invasion. Thus, M cells have attracted lots of attention as a major target of the mucosal immune system. Here, we report that caveolin-1 plays a crucial role in the entry of Salmonella into M cells. We established an in vitro M-like cell model in which polarized enterocyte-like Caco-2 cells created after co-culturing with the Raji B cell line that underwent a phenotypic switch to a form that morphologically and functionally resembles the specialized antigen-transporting M cells. Caveolin-1 was highly expressed in the M-like cells, while not in Caco-2 cells, and a great number of Salmonella infected caveolin-1-expressing M-like cells. To elucidate the role of caveolin-1 in the entry of Salmonella, we downregulated caveolin-1 expression by siRNA and analyzed the level of Salmonella transcytosis across the M-like cells. Transcytosis of Salmonella was markedly reduced by downregulation of caveolin-1 in the M-like cells. These results suggest that caveolin-1 is implicated in the gateway of microbial pathogens through M cells, and, thus, provides a new target of mucosal immunity.

Shewanella fodinae sp. nov., isolated from a coal mine and from a marine lagoon

Strains JC15(T) and JC19 were isolated from samples collected from different locations in India, including a coal mine and a marine lagoon. Both strains were Gram-stain-negative rods, motile by means of a single polar flagellum, catalase- and oxidase-positive, and hydrolysed casein, produced H(2)S and showed beta-haemolysis. Strain JC15(T) grew optimally at pH 6 (range pH 5-8) while strain JC19 grew optimally at pH 7 (range pH 6-9) and both had a growth temperature optimum of 30-37 degrees C (range 22-40 degrees C). Both strains could grow chemo-organoheterotrophically and chemolithoautotrophically. Neither strain required NaCl for growth and both could tolerate up to 9 % (w/v) NaCl, with optimum growth at 5 % NaCl. Vitamin B(12) was required as a growth factor by both strains. The major fatty acids were iso-C(15 : 0), C(17 : 1)omega8c and iso-C(13 : 0) 3-OH. The DNA G+C contents of strains JC15(T) and JC19 were 53.6 and 54.3 mol%, respectively. A phylogenetic tree based on 16S rRNA gene sequence analysis showed that strains JC15(T) and JC19 were most closely related to Shewanella haliotis DW01(T) (approximately 94 % sequence similarity) and to other members of the genus Shewanella. Genomic relatedness (DNA-DNA hybridization) between strains JC15(T) and JC19 is 88 %. On the basis of phenotypic and molecular genetic evidence, strain JC15(T) represents a novel species of the genus Shewanella, for which the name Shewanella fodinae sp. nov. is proposed. The type strain is JC15(T) (=CCUG 57102(T) =NBRC 105216(T) =KCTC 22506(T)).

Alterations of epinephrine-induced gluconeogenesis in aging

The effects of glucagon and epinephrine on gluconeogenesis in young (4 month) and old (24 month) Fisher 344 rat hepatocytes were compared. In contrast to glucagon, which had a similar effect on gluconeogenesis in both young and old cells, epinephrine caused a smaller increase in gluconeogenesis in old rat hepatocytes than in young hepatocytes. beta2 adrenergic receptor (beta2-AR) expression slightly decreased in aged rat liver, and there were differences between young and old hepatocytes in their patterns of G protein coupled receptor kinases, which are involved in the activation of beta2-AR receptor signal desensitization. The major isoform of the kinase changed from GRK2 to GRK3 and the expression of beta-arrestin, which is recruited by the phosphorylated beta2-AR for internalization and degradation, increased in aged rat liver. GRK3 overexpression also decreased the glucose output from young rat hepatocytes. We conclude that an age-associated reduction in epinephrine-induced gluconeogenesis occurs through the epinephrine receptor desensitizing system.

Shewanella chilikensis sp. nov., a moderately alkaliphilic gammaproteobacterium isolated from a lagoon

A Gram-negative, motile, rod-shaped, facultatively anaerobic bacterium was isolated from sediment of Chilika Lagoon, a brackish water lagoon in India. The strain, designated JC5(T), was able to grow in the presence of 0-8.0 % NaCl and at pH 7.0-10.0. The isolate was positive for oxidase and catalase and exhibited alpha-haemolysis. The major fatty acids were iso-C(15 : 0) (18.3 %), C(16 : 0) (11.3 %), C(17 : 1)omega8c (13.1 %) and a summed feature, C(16 : 1)omega7c and/or C(16 : 1)omega6c (15.1 %). The genomic DNA G+C content was 54.6 mol%. A phylogenetic tree based on the 16S rRNA gene sequences showed that strain JC5(T) forms a lineage within the genus Shewanella and is closely related to Shewanella haliotis DW01(T) (98.0 %), Shewanella algae ATCC 51192(T) (97.6 %) and Shewanella marina C4(T) (95.8 %). Further, genomic DNA-DNA hybridization of strain JC5(T) with S. haliotis DW01(T) and S. algae ATCC 51192(T) showed relatedness of only 42 and 23 %, respectively. On the basis of phenotypic and molecular genetic evidence, strain JC5(T) represents a novel species of the genus Shewanella, for which the name Shewanella chilikensis sp. nov. is proposed. The type strain is JC5(T) (=CCUG 57101(T) =NBRC 105217(T) =KCTC 22540(T)).

Time-dependent differential gene expression in lysophosphatidic acid-treated young and senescent human diploid fibroblasts

The gene expression profiles of lysophosphatidic acid (LPA)-treated young and senescent human diploid fibroblasts (HDFs) were examined using cDNA microarray analysis. The expression of some genes, including EGR 1/3 and MRRF, was controlled by LPA similarly in young and senescent cells, showing a typical time-dependent up-and-down expression profile. In contrast, some other genes, including DUSP6, CYR61, and F3, showed sustained upregulation in senescent HDFs later after LPA treatment. These genes might be involved in altered LPA responsiveness during the aging process.

Targeting major vault protein in senescence-associated apoptosis resistance

BACKGROUND

Recent studies have shown that major vault protein (MVP) is involved in intracellular signaling, cell survival, differentiation and innate immunity and that it is not directly responsible for nucleo-cytoplasmic drug transport in multi-drug-resistant cancer cell lines. Recently, we reported that MVP increases with age both in vitro and in vivo, and that age-related upregulation of MVP facilitates apoptosis resistance of senescent human diploid fibroblasts (HDFs) based on the interaction with c-Jun-mediated downregulation of bcl-2.

OBJECTIVES

To discuss the role of MVP in cell survival and signaling in the development of resistance to apoptosis exhibited by senescent HDFs.

CONCLUSIONS

MVP represents a versatile platform for regulation of cellular signaling and survival and is a potential therapeutic target for modulation of resistance to apoptosis, implicated in aging modulation and cancer treatment.

Lupus-associated pancreatitis complicated by pancreatic pseudocyst and central nervous system vasculitis

Pancreatitis is an uncommon manifestation of systemic lupus erythematosus (SLE), but this can occasionally cause major complications. We report in this article, a case of 33-year-old female patient who developed lupus-associated pancreatitis that was subsequently complicated by pancreatic pseudocyst and central nervous system (CNS) vasculitis. Abdominal computed tomography (CT) showed an oedematous swelling of the pancreas and a pseudocyst measuring 4 x 3 cm2. Brain magnetic resonance imaging (MRI) showed multiple high-signal intensity lesions in both cerebral hemispheres. The pseudocyst did not completely resolve with high-dose steroid therapy, and it was later complicated by infection and rupture. After a surgical drainage for the complicated pseudocyst, her clinical symptoms and signs were markedly improved. This case shows the importance of performing early drainage rather than conservative treatment for a pancreatic pseudocyst in a patient with lupus-associated pancreatitis.