β-thalassemia mutations in the Portuguese population

Summary In this study we have carried out haplotype analysis on the -globin gene cluster and characterized the -thalassemia mutation by oligonucleotide hybridization in 14 patients with thalassemia major and 5 with sickle cell/-thalassemia originating from southern Portugal. We found that three mutations, namely the °-39, ° IVS-1 nt 1 and ⁺ IVS-1 nt 110 are prevalent accounting for 53%, 32% and 10% of the -thalassemia chromosomes respectively. In general each mutation was associated with a specific chromosomal haplotype; the ° mutation, however, was linked to three different haplotypes. These results indicate that three oligo-probes complementary to the most common mutations allow prenatal diagnosis by oligonucleotide analysis in 96% of the couples at risk of having offspring with thalassemia major in southern Portugal.     

MIR34A regulates autophagy and apoptosis by targeting HMGB1 in the retinoblastoma cell

MIR34A (microRNA 34a) is a tumor suppressor gene, but how it regulates chemotherapy response and resistance is not completely understood. Here, we show that the microRNA MIR34A-dependent high mobility group box 1 (HMGB1) downregulation inhibits autophagy and enhances chemotherapy-induced apoptosis in the retinoblastoma cell. HMGB1 is a multifaceted protein with a key role in autophagy, a self-degradative, homeostatic process with a context-specific role in cancer. MIR34A inhibits HMGB1 expression through a direct MIR34A-binding site within the HMGB1 3′ untranslated region. MIR34A inhibition of HMGB1 leads to a decrease in autophagy under starvation conditions or chemotherapy treatment. Inhibition of autophagy promotes oxidative injury and DNA damage and increases subsequent CASP3 activity, CASP3 cleavage, and PARP1 [poly (ADP-ribose) polymerase 1] cleavage, which are important to the apoptotic process. Finally, upregulation of MIR34A, knockdown of HMGB1, or inhibition of autophagy (e.g., knockdown of ATG5 and BECN1) restores chemosensitivity and enhances tumor cell death in the retinoblastoma cell. These data provide new insights into the mechanisms governing the regulation of HMGB1 expression by microRNA and their possible contribution to autophagy and drug resistance.     

The Effects of Operational Conditions on the Respiration Rate of Tubificidae

Tubificidae is often used in the wastewater treatment systems to minimize the sludge production because it can be fed on the activated sludge. The process conditions have effect on the growth, reproduction, and sludge reduction efficiency of Tubificidae. The effects of the water quality, density of worms, pH, temperature and dissolved oxygen (DO) concentration on the respiration rate of Tubificidae were investigated to determine the optimal conditions for the growth and metabolism of the worms and reveal the mechanisms involving the efficient sludge reduction in terms of these conditions. It was observed that the respiration rate was highest in the water discharged from an ecosystem that included symbiotic Tubificidae and microbes and was lowest in distilled water. Considering density of the worms, the highest rate was 81.72±5.12 mg O₂/g(dry weight)·h·L with 0.25 g (wet weight) of worms in 1 L test flask. The maximum Tubificidae respiration rate was observed at a pH of 8.0±0.05, a rate that was more than twice as high as those observed at other pH values. The respiration rate increased in the temperature range of ∼8°C–22°C, whereas the rate declined in the temperature range of ∼22°C–30°C. The respiration rate of Tubificidae was very high for DO range of ∼3.5–4.5 mg/L, and the rates were relatively low for out of this DO range. The results of this study revealed the process conditions which influenced the growth, and reproduction of Tubificidae and sludge reduction at a microscopic level, which could be a theoretical basis for the cultivation and application of Tubificidae in wastewater treatment plants.     

In vitro antiviral activity of sulfated Auricularia auricula polysaccharides

Total Auricularia auricula polysaccharide (AAP(t)) was prepared by extracting and removing the proteins. Column chromatography was used to further graded it into AAP(1) and AAP(2). Three AAPs were modified by chlorosulfonic acid-pyridine method to obtain three sulfated AAPs (sAAPs), sAAP(t), sAAP(1) and sAAP(2), respectively. Three sAAPs and Newcastle disease virus (NDV) were added into cultivation system of chicken embryo fibroblast (CEF) in three manners, pre-, post- and simultaneous-adding polysaccharide with NDV respectively, taking three non-modified AAPs as control. Their anti-viral activities were compared by MTT method. The results showed that sAAPs and AAPs at a certain concentration could significantly inhibit the cellular infectivity of NDV in three manners. The effects of sAAPs were better than that of AAPs. It indicated that sulfated modification could enhance the antiviral activity of AAP. sAAP(1) and sAAP(t) possessed stronger activity and would be as the component of a new-type antiviral drug.     

<Emphasis Type="Italic">Rubellimicrobium roseum</Emphasis> sp. nov., a Gram-negative bacterium isolated from the forest soil sample

A novel pink-coloured, non-spore-forming, non-motile, Gram-negative bacterium, designated YIM 48858^T, is described by using a polyphasic approach. The strain can grow at pH 6.5–9 (optimum at pH 7) and 25–30°C (optimum at 28°C). NaCl is not required for its growth. Positive for oxidase and catalase. Urease activity, nitrate reduction, starch and Tween 80 tests are negative reaction. 16S rRNA gene sequence similarity studies showed that strain YIM 48858^T is a member of the genus Rubellimicrobium, with similarities of 96.3, 95.7 and 95.5% to Rubellimicrobium mesophilum MSL-20^T, Rubellimicrobium aerolatum 5715S-9^T and Rubellimicrobium thermophilum DSM 16684^T, respectively. Q-10 was the predominant respiratory ubiquinone as in the other members of the genus Rubellimicrobium. The major polar lipids were diphosphatidylglycerol, phosphatidylcholine, phosphoglycolipid, glycolipid and the major fatty acids were C18:1 ω7c, C16:0 and C10:0 3-OH, which are very different from the valid published species. The DNA G + C content was 67.7 mol%. Both phylogenetic and chemotaxonomic evidence supports that YIM 48858^T is a novel species of the genus Rubellimicrobium, for which the name Rubellimicrobium roseum sp. nov. is proposed. The type strain is YIM 48858^T (=CCTCC AA 208029^T =KCTC 23202^T).     

Knockdown of TRPV4 suppresses osteoclast differentiation and osteoporosis by inhibiting autophagy through Ca2+–calcineurin–NFATc1 pathway

The aim of this study is to evaluate the effect of transient receptor potential vanilloid 4 (TRPV4) on osteoclast differentiation and osteoporosis, and to investigate the underlying mechanism. The results showed that TRPV4 expression and intracellular Ca²⁺ concentration were significantly upregulated in macrophage colony-stimulating factor (M-CSF)-stimulated and receptor activator of nuclear factor κΒ ligand (RANKL)-stimulated RAW264.7 cells. Furthermore, TRPV4 overexpression further increased the M-CSF- and RANKL-induced number of tartrate-resistant acid phosphatase (TRAP)-positive osteoclasts and expression of osteoclastogenesis-related genes (TRAP, c-Fos, and nuclear factor of activated T cells [NFATc1]), activated the Ca ²⁺–calcineurin–NFATc1 signaling and increased autophagy-related proteins (light chain [LC] 3II and Beclin-1) during osteoclast differentiation. In contrast, TRPV4 knockdown exerted the opposite effects. Mechanically, inhibition of Ca ²⁺–calcineurin–NFATc1 signaling by FK506 or 11R-VIVIT abrogated the TRPV4 overexpression-induced osteoclast differentiation and autophagy induction. Moreover, suppression of autophagy by 3-methyladenine attenuated the TRPV4-induced osteoclast differentiation. In addition, short hairpin RNA TRPV4-lentivirus administration significantly diminished the increased levels of several osteoclastogenesis-related genes (RANKL, TRAP, and tumor necrosis factor-α), alleviated the disturbed microarchitecture of lumbar vertebrae, restored the decreased bone mineral density, ratio of bone volume to total tissue volume, trabecular thickness, and trabecular number, and diminished the increased trabecular separation, in ovariectomy (OVX)-induced osteoporosis mice. Consistent with the in vitro data, TRPV4 knockdown significantly decreased the induced number of TRAP-positive osteoclasts, the increased LC3 and NFATc1 expression in the lumbar vertebrae of OVX mice. In conclusion, TRPV4 knockdown suppresses osteoclast differentiation and osteoporosis by inhibiting autophagy through Ca ²⁺–calcineurin–NFATc1 pathway.     

Modulation of Exogenous Glutathione in Phytochelatins and Photosynthetic Performance Against Cd Stress in the Two Rice Genotypes Differing in Cd Tolerance

Greenhouse hydroponic experiments were conducted using Cd-sensitive (Xiushui63) and tolerant (Bing97252) rice genotypes to evaluate genotypic differences in response of photosynthesis and phytochelatins to Cd toxicity in the presence of exogenous glutathione (GSH). Plant height, chlorophyll content, net photosynthetic rate (Pn), and biomass decreased in 5 and 50 μM Cd treatments, and Cd-sensitive genotype showed more severe reduction than the tolerant one. Cadmium stress caused decrease in maximal photochemical efficiency of PSII (Fv/Fm) and effective PSII quantum yield [Y(II)] and increase in quantum yield of regulated energy dissipation [Y(NPQ)], with changes in Cd-sensitive genotype being more evident. Cadmium-induced phytochelatins (PCs), GSH, and cysteine accumulation was observed in roots of both genotypes, with markedly higher level in PCs and GSH on day 5 in Bing97252 compared with that measured in Xiushui63. Exogenous GSH significantly alleviated growth inhibition in Xiushui63 under 5 μM Cd and in both genotypes in 50 μM Cd. External GSH significantly increased chlorophyll content, Pn, Fv/Fm, and Y(II) of plants exposed to Cd, but decreased Y(NPQ) and the coefficient of non-photochemical quenching (qN). GSH addition significantly increased root GSH content in plants under Cd exposure (except day 5 of 50 μM Cd) and induced up-regulation in PCs of 5 μM-Cd-treated Bing97252 throughout the 15-day and Xiushui63 of 5-day exposure. The results suggest that genotypic difference in the tolerance to Cd stress was positively linked to the capacity in elevation of GSH and PCs, and that alleviation of Cd toxicity by GSH is related to significant improvement in chlorophyll content, photosynthetic performance, and root GSH levels.     

鹅掌楸苗期动态生命表

报道了鹅掌楸在苗圃播种后的出苗率和幼苗存活率,根据定期观察数据编制了苗期动态生命表。结果表明,4个种源的出苗率都很低(1.64%～3.05%),比其各自的饱满种子率低得多;天然种源的出苗率高于栽培的种源,但前者的出苗数占饱满种子数的比例却低于后者。至一个生长季以后,幼苗存活率仅占出苗数的16%～27%,而黄山种源与庐山种源的交配后代则高达60%,明显地高于其亲本和其它种源。种子大小对于出苗率和幼苗存活率没有直接影响。最后讨论了遗传因素和生存环境对幼苗存活的影响,并认为种子和幼苗适合度低是鹅掌楸致濒的重要原因之一。