[Comparative analysis of metagenomic and 16S rDNA sequencing in gut microbiota of healthy elderly].

Objective: To explore the differences in subsequent analysis between metagenomic and 16Sr DNA sequencing in compositionally characterizing gut microbiota of healthy elderly. Methods: By using a panel study design, five monthly repeated measurements were performed among 76 healthy older people in Jinan City, Shandong Province. Their fecal samples were collected, and genomic DNA was extracted and analyzed through metagenomic and 16Sr DNA sequencing to compare the composition and diversity of gut microbiota. The correlation between species abundance and α diversity was analyzed by Pearson correlation analysis, and the correlation between species abundance and ß diversity was determined by Procrustes analysis. Results: The age of 76 participants was (65.07±2.75), and the body mass index was (25.03±2.40) kg/m2. There were 38 males and 38 females. A total of 345 fecal samples were obtained from five monthly repeated measurements. Compared with 16S rDNA sequencing, metagenomic sequencing showed more annotated species at each level. The difference in the number of two sequencing species increased with the decrease of the level. Although there were significant differences in species richness between the two sequencing methods. Their species richness was highly correlated at both phylum (r=0.88, P<0.001) and genus (r=0.77, P<0.001) levels. Bacteroidetes and Firmicutes were the common dominant species. Gut microbiota diversity analysis further showed that there was a significantly positive correlation between α diversity (r=0.70, P<0.001) and ß diversities (M2=0.84, P<0.05) in the two groups. Conclusion: The annotation efficiency of metagenomic sequencing is much higher than that of 16S rDNA sequencing. The two sequencing methods are consistent in phylum abundance as well as α diversity.

AKT-GSK3ß Signaling Pathway Regulates Mitochondrial Dysfunction-Associated OPA1 Cleavage Contributing to Osteoblast Apoptosis: Preventative Effects of Hydroxytyrosol.

Oxidative stress (OS) induces osteoblast apoptosis, which plays a crucial role in the initiation and progression of osteoporosis. Although OS is closely associated with mitochondrial dysfunction, detailed mitochondrial mechanisms underlying OS-induced osteoblast apoptosis have not been thoroughly elucidated to date. In the present study, we found that mitochondrial abnormalities largely contributed to OS-induced osteoblast apoptosis, as evidenced by enhanced production of mitochondrial reactive oxygen species; considerable reduction in mitochondrial respiratory chain complex activity, mitochondrial membrane potential, and adenosine triphosphate production; abnormality in mitochondrial morphology; and alteration of mitochondrial dynamics. These mitochondrial abnormalities were primarily mediated by an imbalance in mitochondrial fusion and fission through a protein kinase B- (AKT-) glycogen synthase kinase 3ß- (GSK3ß-) optic atrophy 1- (OPA1-) dependent mechanism. Hydroxytyrosol (3,4-dihydroxyphenylethanol (HT)), an important compound in virgin olive oil, significantly prevented OS-induced osteoblast apoptosis. Specifically, HT inhibited OS-induced mitochondrial dysfunction by decreasing OPA1 cleavage and by increasing AKT and GSK3ß phosphorylation. Together, our results indicate that the AKT-GSK3ß signaling pathway regulates mitochondrial dysfunction-associated OPA1 cleavage, which may contribute to OS-induced osteoblast apoptosis. Moreover, our results suggest that HT could be an effective nutrient for preventing osteoporosis development.

RAGE-dependent mitochondria pathway: a novel target of silibinin against apoptosis of osteoblastic cells induced by advanced glycation end products.

Advanced glycation end products (AGEs) can stimulate osteoblast apoptosis and have a critical role in the pathophysiology of diabetic osteoporosis. Mitochondrial abnormalities are closely related to osteoblast dysfunction. However, it remains unclear whether mitochondrial abnormalities are involved in AGE-induced osteoblastic cell apoptosis. Silibinin, a major flavonolignan compound of silimarin, has strong antioxidant and mitochondria-protective properties. In the present study, we explored the possible mitochondrial mechanisms underlying AGE-induced apoptosis of osteoblastic cells and the effect of silibinin on osteoblastic cell apoptosis. We demonstrated that mitochondrial abnormalities largely contributed to AGE-induced apoptosis of osteoblastic cells, as evidenced by enhanced mitochondrial oxidative stress, conspicuous reduction in mitochondrial membrane potential and adenosine triphosphate production, abnormal mitochondrial morphology, and altered mitochondrial dynamics. These AGE-induced mitochondrial abnormalities were mainly mediated by the receptor of AGEs (RAGE). In addition, we found that silibinin directly downregulated the expression of RAGE and modulated RAGE-mediated mitochondrial pathways, thereby preventing AGE-induced apoptosis of osteoblastic cells. This study not only provides a new insight into the mitochondrial mechanisms underlying AGE-induced osteoblastic cell apoptosis, but also lays a foundation for the clinical use of silibinin for the prevention or treatment of diabetic osteoporosis.

[One-night-stand behavior and associated factors among young men who have sex with men in Wuhan, China].

Objective: This present study was to examine the prevalence and determinants of one-night-stand behavior among young men who have sex with men (YMSM). Methods: A total of 403 YMSM aged 16 to 25 were recruited through internet promotion, extending activity and HIV VCT in Wuhan. Data was gathered through anonymous questionnaire. Binary logistic regression was used to examine factors associated with one-night-stand behavior. Results: Of the 398 YMSM, 48.99% (195/398) reported having had casual sex in the last 6 months. Of the ones having had casual sex, 34.29% (60/175) and 28.65% (49/171) reported using condoms consistently during anal or oral sexual contacts, respectively. These figures were lower than those of YMSM not having casual sexual contacts [with anal sex as 49.08% (80/163) and oral sex as 38.85% (61/157)]. 76.80% (149/194) of the YMSM reported having had multiple sexual partners, with the figure higher than those without [33.15% (60/181)] (P<0.01). Results from the logistic regression analysis showed that the following factors seemed to be associated with casual sex activities among YMSM, including: often using internet, (OR=4.89, 95%CI: 1.90-12.54), taking illegal drugs (OR=2.72, 95%CI: 1.60-4.63). Conclusions: YMSM who had engaged in casual sex, practicing unprotected sex or having multiple sexual partners, were recognized as high risk population. Targeted intervention programs are needed to decrease the one-night-stand behavior. Internet intervention strategy seemed an important method to serve the purpose.

Overexpression of BTG2 suppresses growth, migration, and invasion of human renal carcinoma cells in vitro.

The objective of the study was to investigate the impact of BTG2 on growth, migration and invasion of human clear cell renal cell carcinoma (ccRCC) cells. Endogenous expression of BTG2 was evaluated in the ccRCC cell lines (Caki-1, 786-O and Caki-2) and noncancerous human renal proximal tubular cell lines (HKC, HK-2 and RPTEC). BTG2 expression was decreased in the ccRCC cells compared with the noncancerous cells (P < 0.01). Then Caki-1 and 786-O cells described as suitable transfection hosts were used in transfection to carry out biological function studies. The three experimental groups were as follows: BTG2-ORF (transfected with BTG2-ORF plasmid), blank-Vector (transfected with pCMV6-Entry), and Cell-alone group (no DNA transfected in). BTG2 expression in the BTG2-ORF groups was significantly higher than that in the controls (P < 0.01). Cell growth was remarkably reduced and the number of migrating or invading cells was reduced in the BTG2-ORF groups compared with the controls (P < 0.01). Furthermore, Matrix Metalloproteinase-9 (MMP-9), Cyclin D1 and Cyclin E expression were reduced in the BTG2-ORF groups compared with the controls. Here, we have provided data for attenuated BTG2 expression in the ccRCC cells. Overexpressed BTG2 could inhibit cell proliferation, migration and invasion of human ccRCC, and the suppressive effects might be due to down-regulation of MMP-9, Cyclin D1 and Cyclin E expression.

Distinct expression and inhibitory function of B and T lymphocyte attenuator on human T cells.

B and T lymphocyte attenuator (BTLA) has been recently identified as a new inhibitory receptor of the CD28 superfamily, with similarities to cytotoxic T lymphocyte activation antigen (CTLA)-4 and programmed death (PD)-1. Engagement of BTLA on T lymphocytes can profoundly reduce the T cell receptor (TCR)-mediated activation. In this study, we generated four monoclonal antibodies (mAbs) against human BTLA. Using the produced mAb 8H9, the BTLA molecule was found to distinctly express on many subgroups of immunocytes and show a regulatory expression, which was in accordance with its unique ligand herpes virus entry mediator (HVEM) in the process of T cell activation. In addition, the expression of BTLA was increased in the CD4(+) and CD8(+) T cells of pleural fluid in lung cancer patients. Furthermore, we showed that the BTLA-induced negative signals could be triggered by mAb 7D7. Cross-linking of BTLA with mAb 7D7 suppressed T lymphocyte proliferation, downregulated the expression of T cell activation marker CD25, and inhibited the production of interferon (IFN)-gamma, interleukin (IL)-2, IL-4, and IL-10.

Suppression of radioactive strontium absorption by sodium alginate in animals and human subjects.

The effect of 23 sodium alginate preparations from different species of algae (Sargassum sp.) and kelp (Laminaria sp.) on reducing the absorption of strontium was studied in detail. A pilot production procedure has been established. Na alginate from S. siliquastrum was proven to be a potent agent for reducing Sr absorption, with high efficiency and virtually no toxicity. It reduced the body burden of strontium 3.3-4.2 fold in rats. Strontium absorption in human subjects was reduced by 78% (+/- 8.9) or completely suppressed the increase of serum Sr at 2 h after ingestion of stable Sr in volunteers and decrease 24 h urine Sr to similar extent. No undesirable effects on gastrointestinal function was observed nor were Ca, Fe, Cu and Zn metabolism changed, both in the animal experiments and in human. It was concluded that alginate preparations derived from Sargassum species are a suitable antidote against radiostrontium absorption on a long-term basis, when added to bread at a 6% level. In cases of emergency, an alginate syrup preparation appears to be more suitable because of its rapid action.

Regional brain trace-element studies in Alzheimer's disease.

Alzheimer's disease (AD) brain trace-element imbalances in the amygdala, hippocampus and nucleus basalis of Meynert (nbM) are found in most cases to be consistent with those previously reported in samples derived principally from AD cerebral cortex (Ehmann et al., 1986). The elevation of mercury in AD nbM, as compared to age-matched controls, is the largest trace-element imbalance observed to date in AD brain. In addition to the general confirmation of imbalances for Cs, Hg, N, Na, P, and Rb noted previously in cerebral cortex samples, imbalances for Fe, K, Sc, and Zn were observed in two regions and one region also exhibited imbalances for both Co and Se. Persistent imbalances for the univalent cations Na, K, Rb and Cs support arguments for a membrane abnormality in AD. The data presented here also provide the first comprehensive simultaneous multi-element determinations in both control and AD nbM.