Involvement of both caspase-dependent and -independent pathways in apoptotic induction by hexaminolevulinate-mediated photodynamic therapy in human lymphoma cells

Photodynamic therapy (PDT) is a cancer treatment based on the interaction of a photosensitizer, light and oxygen. PDT with the endogenous photosensitizer, protoporphyrin IX (PpIX) induced by 5-aminolevulinic acid (ALA) or its derivatives is a modification of this treatment modality with successful application in dermatology. However, the mechanism of cell destruction by ALA-PDT has not been elucidated. In this study a human T-cell lymphoma Jurkat cell line was treated with PDT using hexaminolevulinate (HAL, hexylester of ALA). Four hours following treatment nearly 80% of the cells exhibited typical apoptotic features. Mitochondrial pro-apoptotic proteins were evaluated by Western blots in subcellular fractionated samples. PDT caused cytosolic translocation of cytochrome c and nuclear redistribution of apoptosis-inducing factor (AIF), but the release of mitochondrial Smac/DIABLO, Omi/HtrA2 and EndoG was not observed. The release of cytochrome c was followed by the cleavage of caspase-9 and caspase-3 as well as its downstream substrates, together with oligonucleosomal DNA fragmentation. The pan-caspases inhibitor, z-VAD.fmk, prevented oligonucleosomal DNA fragmentation, but failed to inhibit PDT-mediated apoptosis. The apoptotic induction by AIF-mediated caspase-independent pathway was also found after HAL-PDT with large-scale DNA fragmentation in the presence of z-VAD.fmk. These results demonstrate that cytochrome c-mediated caspase-dependent pathway and AIF-induced caspase-independent pathway are simultaneously involved in the apoptotic induction by PDT. When the cytochrome c-induced caspase-dependent pathway is blocked, the cells go into apoptosis via AIF-mediated pathway, clearly demonstrating that the cytochrome c-mediated caspase-dependent pathway is not required for such apoptotic induction. This finding may have an impact on improved PDT effectiveness.     

GST-Fbe can recognize beta-chains of fibrin(ogen) on explanted materials

Staphylococcus epidermidis, a coagulase-negative staphylococcus (CoNS), is one of the leading pathogens of nosocomial infections, particularly associated with foreign body infections. Adherence of S. epidermidis to fibrinogen deposited on the surfaces of implants is important for the development of foreign body infections. A gene (fbe) encoding a fibrinogen-binding protein from S. epidermidis (Fbe) was identified by shotgun phage display. A portion of fbe was cloned into a GST-fusion vector. Affinity to glutathione-Sepharose by the GST-tag and affinity to fibrinogen-Sepharose by the Fbe part were applied to purify the recombinant Fbe. The purity and efficacy of the methods used in protein purification was compared. Furthermore, the potential physiological role of Fbe was studied by the interaction between GST-Fbe and components extracted from explanted materials in vitro.     

Photoperiodic reactions in conifer species

In Picea abies seedlings the critical night length for bud-set was determined for provenances from different latitudes, longitudes and altitudes within the natural range of the species. The clinal variation of this character was demonstrated. Inheritance studies indicated that this character is controlled by many genes with predominantly additive effects. In seedlings of Pinus sylvestris and Pinus contorta, growth cessation and bud-set took place in all light regimes, thus, even under continuous illumination. A photoperiodic optimum for height growth was determined. The photoperiodic influence on such characters as recurrent flushing of shoots, needle growth, dry matter production and frost resistance was demonstrated for northern and southern populations of the two Pinus species. Shorter nights were needed to induce a particular photoperiodic response in the northern populations as compared with those from the south. The importance of reliable phenological characters for assessing frost hardiness in provenance and progeny trials by means of early tests, is discussed.     

Reactions of D-xylose and D-glucose in alkaline,aqueous solutions

Treatment of D-xylose and D-glucose with 0.63M sodium hydroxide at 96° in an atmosphere of nitrogen yielded, in addition to acidic, aliphatic degradation-products, the following cyclic enols and phenolic compounds: 2-hydroxy-3-methyl-2-cyclopenten-1-one (1), 2-hydroxy-3,4-dimethyl-2-cyclopenten-1-one (2), pyrocatechol (3), 3-methyl-1,2-benzenediol (4), 4-methyl-1,2-benzenediol (5), 3,4-di-methyl-1,2-benzenediol (6), 2-methyl-1,4-benzenediol (7), 2,5-dihydroxyacetophe-none (8), 3-hydroxy-5-methylacetophenone (9), 3,4-dihydroxyacetophenone (10), 3,4-hydroxybenzaldehyde (11), 2,3,4-trihydroxy-5-methylacetophenone (12), and 2,3-dihydroxy-6-methylacetophenone (13).     

Genome-wide analyses implicate 33 loci in heritable dog osteosarcoma, including regulatory variants near CDKN2A/B

Background

Canine osteosarcoma is clinically nearly identical to the human disease, but is common and highly heritable, making genetic dissection feasible.

Results

Through genome-wide association analyses in three breeds (greyhounds, Rottweilers, and Irish wolfhounds), we identify 33 inherited risk loci explaining 55% to 85% of phenotype variance in each breed. The greyhound locus exhibiting the strongest association, located 150 kilobases upstream of the genes CDKN2A/B, is also the most rearranged locus in canine osteosarcoma tumors. The top germline candidate variant is found at a >90% frequency in Rottweilers and Irish wolfhounds, and alters an evolutionarily constrained element that we show has strong enhancer activity in human osteosarcoma cells. In all three breeds, osteosarcoma-associated loci and regions of reduced heterozygosity are enriched for genes in pathways connected to bone differentiation and growth. Several pathways, including one of genes regulated by miR124, are also enriched for somatic copy-number changes in tumors.

Conclusions

Mapping a complex cancer in multiple dog breeds reveals a polygenic spectrum of germline risk factors pointing to specific pathways as drivers of disease.     

The relationship between the val158met catechol-O-methyltransferase (COMT) polymorphism and irritable bowel syndrome

Background

The catechol-O-methyltransferase (COMT) enzyme has a key function in the degradation of catecholamines and a functional polymorphism is val158met. The val/val genotype results in a three to fourfold higher enzymatic activity compared with the met/met genotype, with the val/met genotype exhibiting intermediate activity. Since pain syndromes as well as anxiety and depression are associated to low and high COMT activity respectively and these conditions are all associated with irritable bowel syndrome (IBS) we wanted for the first time to explore the relationship between the polymorphism and IBS.

Methodology/Principal Findings

867 subjects (445 women) representative of the general population and 70 consecutively sampled patients with IBS (61 women) were genotyped for the val158met polymorphism and the IBS patients filled out the Hospital-Anxiety-and-Depression-Scale (HADS) questionnaire, and an IBS symptom diary.

Results

There was a significantly higher occurrence of the val/val genotype in patients compared with controls (30% vs 20%; Chi² (1) 3.98; p = 0.046) and a trend toward a lower occurrence of the val/met genotype in IBS patients compared with controls (39% vs 49%; Chi² (1) 2.89; p = 0.089). Within the IBS patients the val/val carriers exhibited significantly increased bowel frequency (2.6 vs 1.8 stools per day; Chi² (1) 5.3; p = 0.03) and a smaller proportion of stools with incomplete defecation (41% vs 68%; Chi² (1) 4.3; p = 0.04) compared with the rest (val/met+met/met carriers). The val/val carriers also showed a trend for a smaller proportion of hard stools (0% vs 15%; Chi² (1) 3.2; p = 0.08) and a higher frequency of postprandial defecation (26% vs 21%; Chi² (1) 3.0; p = 0.08).

Conclusions/Significance

In this study we found an association between the val/val genotype of the val158met COMT gene and IBS as well as to specific IBS related bowel pattern in IBS patients.     

Pathogenicity island markers, virulence determinants malX and usp, and the capacity of Escherichia coli to persist in infants' commensal microbiotas

Virulence-associated genes in bacteria are often located on chromosomal regions, termed pathogenicity islands (PAIs). Several PAIs are found in Escherichia coli strains that cause extraintestinal infections, but their role in commensal bowel colonization is unknown. Resident strains are enriched in adhesins (P fimbriae and type 1 fimbriae), capsular antigens (K1 and K5), hemolysin, and aerobactin and mostly belong to phylogenetic group B2. Here, we investigated whether six pathogenicity islands and the virulence determinants malX and usp are associated with fitness of E. coli in the infant bowel microbiota. E. coli strains isolated from stools of 130 Swedish infants during the first year of life were examined for their carriage of PAI markers, malX, and usp by PCR. Carriage was related to strain persistence: long-term colonizers (≥12 months) carried significantly more of PAI II from strain CFT703 (II(CFT703)), IV(536,) and II(J96) and malX and usp than intermediate colonizers (1 to 11 months) and transient strains (<3 weeks). The accumulation of PAI markers in each individual strain correlated positively with its time of persistence in the colon. Phylogenetic group B2 accounted for 69% of long-term colonizers, 46% of intermediate colonizers and 14% of transient strains. These results support the hypothesis that some bacterial traits contributing to extraintestinal infections have in fact evolved primarily because they increase the fitness of E. coli in its natural niche, the colon; accordingly, they may be regarded as fitness islands in the gut.