The Dynamic Distribution of Wolbachia and Rickettsia in AsiaII1 Bemisia tabaci.

Wolbachia and Rickettsia are bacterial endosymbionts that can induce a number of reproductive abnormalities in their arthropod hosts. We screened and established the co-infection of Wolbachia and Rickettsia in Bemisia tabaci and compared the spatial and temporal distribution of Wolbachia and Rickettsia in eggs (3-120 h after spawning), nymphs, and adults of B. tabaci by qPCR quantification and fluorescent in situ hybridization (FISH). The results show that the titer of Wolbachia and Rickettsia in the 3-120 h old eggs showed a "w" patterned fluctuation, while the titers of Wolbachia and Rickettsia had a "descending-ascending descending-ascending" change process. The titers of Rickettsia and Wolbachia nymphal and the adult life stages of Asia II1 B. tabaci generally increased with the development of whiteflies. However, the location of Wolbachia and Rickettsia in the egg changed from egg stalk to egg base, and then from egg base to egg posterior, and finally back to the middle of the egg. These results will provide basic information on the quantity and localization of Wolbachia and Rickettsia within different life stages of B. tabaci. These findings help to understand the dynamics of the vertical transmission of symbiotic bacteria.

Rickettsia Infection Benefits Its Whitefly Hosts by Manipulating Their Nutrition and Defense.

Endosymbionts play an essential role in the biology, physiology and immunity of insects. Many insects, including the whitefly Bemisia tabaci, are infected with the facultative endosymbiont Rickettsia. However, the mutualism between Rickettsia and its whitefly host remains unclear. This study investigated the biological and physiological benefits of Rickettsia infection to B. tabaci. Results revealed that infection of Rickettsia increased the fertility, the survival rate from nymph to adult and the number of female whiteflies. In addition, this facilitation caused a significant reduction in nymphal developmental duration but did not affect percentage rate of egg hatching. Rickettsia infected B. tabaci had significantly higher glycogen, soluble sugar and trehalose contents than Rickettsia negative B. tabaci individuals. Rickettsia also improved the immunity of its whitefly hosts. Rickettsia infested B. tabaci had lower mortality rates and higher semi-lethal concentrations (LC50) when exposed to the fungus Akanthomyces attenuatus and the insecticides imidacloprid and spirotetramat. The percentage of parasitism by Encarsia formosa was also reduced by Rickettsia infection. Overall, Rickettsia infection benefits B. tabaci by improving the nutritional composition of its host, and also protects B. tabaci by enhancing its resistance towards insecticides (imidacloprid and spirotetramat), entomopathogenic fungi (A. attenuatus) and its main parasitoid (E. formosa); all of which could significantly impact on current management strategies.

Parasitoid-mediated horizontal transmission of Rickettsia between whiteflies.

Intracellular bacterial endosymbionts of arthropods are mainly transmitted vertically from mother to offspring, but phylogenetically distant insect hosts often harbor identical endosymbionts, indicating that horizontal transmission from one species to another occurs in nature. Here, we investigated the parasitoid Encarsia formosa-mediated horizontal transmission of the endosymbiont Rickettsia between different populations of whitefly Bemisia tabaci MEAM1. Rickettsia was successfully transmitted from the positive MEAM1 nymphs (R +) into E. formosa and retained at least for 48 h in E. formosa adults. Fluorescence in situ hybridization (FISH) visualization results revealed that the ovipositors, mouthparts, and digestive tract of parasitoid adults get contaminated with Rickettsia. Random non-lethal probing of Rickettisia-negative (R- ) MEAM1 nymphs by these Rickettsia-carrying E. formosa resulted in newly infected MEAM1 nymphs, and the vertical transmission of Rickettsia within the recipient females can remain at least up to F3 generation. Further phylogenetic analyses revealed that Rickettsia had high fidelity during the horizontal transmission in whiteflies and parasitoids. Our findings may help to explain why Rickettsia bacteria are so abundant in arthropods and suggest that, in some insect species that shared the same parasitoids, Rickettsia may be maintained in populations by horizontal transmission.

Induction of apoptosis and autophagy by calcifying nanoparticles in human bladder cancer cells.

Calcifying nanoparticles have been linked to various types of human disease, but how they contribute to disease processes is unclear. Here, we examined whether and how calcifying nanoparticles isolated from patients with kidney stones are cytotoxic to human bladder cancer cells. Calcifying nanoparticles were isolated from midstream urine of patients with renal calcium oxalate stones and examined by electron microscopy. Human bladder cancer cells (EJ cells) were cultured in the presence of calcifying nanoparticles or nanohydroxyapatites for 12 and 72 h and examined for toxicity using the Cell Counting Kit-8, for autophagy using transmission electron microscopy and confocal microscopy, and for apoptosis using fluorescence microscopy, transmission electron microscopy, and flow cytometry. Changes in protein expression were analyzed by Western blotting. The results showed that the size and shape of the isolated calcifying nanoparticles were as expected. Calcifying nanoparticles were cytotoxic to EJ cells, more so than nanohydroxyapatites, and this was due, at least in part, to the production of intracellular reactive oxygen species. Transmission electron microscopy showed that calcifying nanoparticles were packaged into vesicles and autolysosomes. Calcifying nanoparticles induced greater autophagy and apoptosis than nanohydroxyapatites. Our findings demonstrate that calcifying nanoparticles can trigger bladder cancer cell injury by boosting reactive oxygen species production and stimulating autophagy and apoptosis.

Androgen receptor gene polymorphisms and risk of prostate cancer: a meta-analysis.

Although the association between CAG and GGN repeats in the androgen receptor gene and prostate cancer risk has been widely studied, it remains controversial from previous meta-analyses and narrative reviews. Therefore, we performed this meta-analysis to provide more precise estimates with sufficient power. A total of 51 publications with 61 studies for CAG repeats and 14 publications with 16 studies for GGN repeats were identified in the meta-analysis. The results showed that short CAG repeats (<22 repeats) carriers presented an elevated risk of prostate cancer than long CAG repeats (≥22) carriers (OR = 1.31, 95% CI 1.16 to 1.47). Prostate cancer cases presented an average fewer CAG repeats (MD = -0.85, 95% CI -1.28 to -0.42) than controls. Short GGN repeats (≤16) carriers presented an increased risk of prostate cancer than long GGN repeats (>16) carriers (OR = 1.38, 95% CI 1.05 to 1.82). In subgroup analyses, the abovementioned significant association was predominantly observed in Caucasian populations. The meta-analysis showed that short CAG and GGN repeats in androgen receptor gene were associated with increased risk of prostate cancer, especially in Caucasians.

Genetic association between interluekin-4 rs2243250 polymorphism and gastric cancer susceptibility: evidence based on a meta-analysis.

PURPOSE: Numerous studies have suggested that the interleukin-4 (IL-4) rs2243250 polymorphism is associated with gastric cancer susceptibility. However, the results were inconsistent. Hence, we carried out a meta-analysis to confirm the conclusion. METHODS: We searched PubMed, Embase, CBM, CNKI, and Wanfang Data to identify relevant studies up to August 20, 2015. Odds ratio (OR) and 95% confidence interval (CI) were used to estimate the association between IL-4 rs2243250 polymorphism and gastric cancer susceptibility. All the statistical analyses were performed with Stata 12.0 software. RESULTS: A total of eleven published case-control studies were identified, including 2,247 gastric cancer patients and 3,370 controls. Overall, no significant association between IL-4 rs2243250 polymorphism and gastric cancer susceptibility was observed in this meta-analysis (T vs C: OR =1.05, 95% CI =0.95-1.17; TT vs CC: OR =1.20, 95% CI =0.89-1.63; CT vs CC: OR =1.14, 95% CI =0.87-1.48; TT + CT vs CC: OR =1.13, 95% CI =0.89-1.44; TT vs CT + CC: OR =1.02, 95% CI =0.88-1.20). Similar results were found in subgroup analyses according to ethnicity and Hardy-Weinberg equilibrium in controls. CONCLUSION: This meta-analysis suggests that IL-4 rs2243250 polymorphism may not be associated with gastric cancer susceptibility. Further studies are needed to validate this conclusion.