Genetic research and clinical analysis of deletional Chinese Gγ+(Aγδß)0 -thalassemia and Southeast Asian HPFH in South China.

Chinese Gγ+(Aγδß)0-thalassemia and SEA-HPFH are the most common types of ß-globin gene cluster deletion in Chinese population. The aim of the study was to analyze clinical features of deletional Chinese Gγ+(Aγδß)0-thalassemia and Southeast Asian hereditary persistence of fetal hemoglobin (SEA-HPFH) in South China. A total of 930 subjects with fetal hemoglobin (HbF) level ≥ 2% were selected on genetic research of Chinese Gγ+(Aγδß)0-thalassemia and SEA-HPFH. The gap polymerase chain reaction was performed to identify the deletions. One hundred cases of Chinese Gγ+(Aγδß)0-thalassemia were detected, including 90 cases of Chinese Gγ+(Aγδß)0/ßN-thalassemia, 7 cases of Chinese Gγ+(Aγδß)0 /ßN-thalassemia combined with α-thalassemia, 2 cases of Chinese Gγ+(Aγδß)0-thalassemia combined with ß-thalassemia, and 1 case of Chinese Gγ+(Aγδß)0-thalassemia combined with ß-gene mutation. One hundred nine cases of SEA-HPFH were detected, including 97 cases of SEA-HPFH/ßN, 9 cases of SEA-HPFH/ßN combined with α-thalassemia, 2 cases of SEA-HPFH combined with ß-thalassemia, and 1 case of SEA-HPFH combined with ß-gene mutation. Statistical analysis indicates significant differences in MCV (mean corpuscular volume), MCH (mean corpuscular hemoglobin), and HbA2 and HbF levels between Chinese Gγ+(Aγδß)0-thalassemia heterozygotes and SEA-HPFH heterozygotes (P < 0.001). There are statistical differences in hematological parameters between them. Clinical phenotypic analysis can provide guidance for genetic counseling and prenatal diagnosis.

Novel Bioactive Peptides from Meretrix meretrix Protect Caenorhabditis elegans against Free Radical-Induced Oxidative Stress through the Stress Response Factor DAF-16/FOXO.

The hard clam Meretrix meretrix, which has been traditionally used as medicine and seafood, was used in this study to isolate antioxidant peptides. First, a peptide-rich extract was tested for its protective effect against paraquat-induced oxidative stress using the nematode model Caenorhabditis elegans. Then, three novel antioxidant peptides; MmP4 (LSDRLEETGGASS), MmP11 (KEGCREPETEKGHR) and MmP19 (IVTNWDDMEK), were identified and were found to increase the resistance of nematodes against paraquat. Circular dichroism spectroscopy revealed that MmP4 was predominantly in beta-sheet conformation, while MmP11 and MmP19 were primarily in random coil conformation. Using transgenic nematode models, the peptides were shown to promote nuclear translocation of the DAF-16/FOXO transcription factor, a pivotal regulator of stress response and lifespan, and induce the expression of superoxide dismutase 3 (SOD-3), an antioxidant enzyme. Analysis of DAF-16 target genes by real-time PCR reveals that sod-3 was up-regulated by MmP4, MmP11 and MmP19 while ctl-1 and ctl-2 were also up-regulated by MmP4. Further examination of daf-16 using RNA interference suggests that the peptide-increased resistance of C. elegans to oxidative stress was DAF-16 dependent. Taken together, these data demonstrate the antioxidant activity of M. meretrix peptides, which are associated with activation of the stress response factor DAF-16 and regulation of the antioxidant enzyme genes.

Physicochemical Characterization and Functional Analysis of the Polysaccharide from the Edible Microalga Nostoc sphaeroides.

Nostoc colonies have been used as food and medicine for centuries, and their main supporting matrix is polysaccharides, which help Nostoc cells resist various environmental stresses including oxidative stress. Here we isolated a polysaccharide, nostoglycan, from cultured Nostocsphaeroides colonies and determined its physicochemical properties, which revealed a characteristic infrared absorption spectrum typical of polysaccharides and an amorphous morphology with rough surfaces. We also show that nostoglycan has strong moisture absorption and retention capacities and a high relative viscosity. Using Caenorhabditis elegans models, we then demonstrate that nostoglycan is capable of improving overall survival rate of the animals under increased oxidative stress caused by paraquat. Nostoglycan also reduces reactive oxygen species level, inhibits protein carbonyl formation and lipid peroxidation, and increases activities of superoxide dismutase and catalase in paraquat-exposed nematodes. As oxidative stress may drive tumor progression, we further demonstrate that nostoglycan can suppress the proliferation of several types of tumor cells and induce apoptosis of human lung adenocarcinoma A549 cells via caspase-3 activation. Together, our results yield important information on the physicochemical characteristics and demonstrate the antioxidant and anti-proliferative functions of nostoglycan, and thus provide an insight into its potential in food and health industries.

Antioxidant and anti-aging effects of a sea cucumber protein hydrolyzate and bioinformatic characterization of its composing peptides.

Sea cucumbers have been used as food delicacies and traditional medicine for centuries, and their health benefits are partly attributed to their repertoire of proteins. Peptides prepared from the sea cucumber Apostichopus japonicus are reported to have in vitro antioxidant activities. Here, we investigated the in vivo antioxidant capacity of AjPH, a peptide-rich A. japonicus protein hydrolyzate, and found that AjPH is capable of increasing the survival rate and reducing the reactive oxygen species (ROS) level in the animal model Caenorhabditis elegans under increased oxidative stress induced by paraquat. AjPH is also shown to enhance the antioxidant defense system in paraquat-exposed nematodes, including upregulation of superoxide dismutase and catalase activities and reduction of malondialdehyde contents. To explore underpinning antioxidant mechanisms, cellular and chemical assays were used to demonstrate that AjPH not only reduces ROS accumulation in cells but also directly scavenges DPPH free radicals. Further studies indicate that AjPH can decrease age pigments and extend lifespan but does not reduce food intake, body length and brood size of the nematodes, demonstrating its capacity to delay physiological aging. Using activity-guided fractionation by ultrafiltration and gel filtration, we then isolated antioxidant fractions from AjPH and identified the sequences of their composing peptides, which were subjected to in silico analysis for prospective motifs, physicochemical properties and antioxidant potential. Taken together, our results provide an insight into the nutraceutical potential of the sea cucumber protein hydrolyzate for aging and related conditions and also a basis for future mechanistic studies of individual antioxidant peptides.