The multipartite mitochondrial genome of Liposcelis bostrychophila: insights into the evolution of mitochondrial genomes in bilateral animals

Booklice (order Psocoptera) in the genus Liposcelis are major pests to stored grains worldwide and are closely related to parasitic lice (order Phthiraptera). We sequenced the mitochondrial (mt) genome of Liposcelis bostrychophila and found that the typical single mt chromosome of bilateral animals has fragmented into and been replaced by two medium-sized chromosomes in this booklouse; each of these chromosomes has about half of the genes of the typical mt chromosome of bilateral animals. These mt chromosomes are 8,530 bp (mt chromosome I) and 7,933 bp (mt chromosome II) in size. Intriguingly, mt chromosome I is twice as abundant as chromosome II. It appears that the selection pressure for compact mt genomes in bilateral animals favors small mt chromosomes when small mt chromosomes co-exist with the typical large mt chromosomes. Thus, small mt chromosomes may have selective advantages over large mt chromosomes in bilateral animals. Phylogenetic analyses of mt genome sequences of Psocodea (i.e. Psocoptera plus Phthiraptera) indicate that: 1) the order Psocoptera (booklice and barklice) is paraphyletic; and 2) the order Phthiraptera (the parasitic lice) is monophyletic. Within parasitic lice, however, the suborder Ischnocera is paraphyletic; this differs from the traditional view that each suborder of parasitic lice is monophyletic.     

HDAC Inhibitor L-Carnitine and Proteasome Inhibitor Bortezomib Synergistically Exert Anti-Tumor Activity In Vitro and In Vivo

Combinations of proteasome inhibitors and histone deacetylases (HDAC) inhibitors appear to be the most potent to produce synergistic cytotoxicity in preclinical trials. We have recently confirmed that L-carnitine (LC) is an endogenous HDAC inhibitor. In the current study, the anti-tumor effect of LC plus proteasome inhibitor bortezomib (velcade, Vel) was investigated both in cultured hepatoma cancer cells and in Balb/c mice bearing HepG2 tumor. Cell death and cell viability were assayed by flow cytometry and MTS, respectively. Gene, mRNA expression and protein levels were detected by gene microarray, quantitative real-time PCR and Western blot, respectively. The effect of Vel on the acetylation of histone H3 associated with the p21^cip1 gene promoter was examined by using ChIP assay and proteasome peptidase activity was detected by cell-based chymotrypsin-like (CT-like) activity assay. Here we report that (i) the combination of LC and Vel synergistically induces cytotoxicity in vitro; (ii) the combination also synergistically inhibits tumor growth in vivo; (iii) two major pathways are involved in the synergistical effects of the combinational treatment: increased p21^cip1 expression and histone acetylation in vitro and in vivo and enhanced Vel-induced proteasome inhibition by LC. The synergistic effect of LC and Vel in cancer therapy should have great potential in the future clinical trials.     

The Role of Insulin C-Peptide in the Coevolution Analyses of the Insulin Signaling Pathway: A Hint for Its Functions

As the linker between the A chain and B chain of proinsulin, C-peptide displays high variability in length and amino acid composition, and has been considered as an inert byproduct of insulin synthesis and processing for many years. Recent studies have suggested that C-peptide can act as a bioactive hormone, exerting various biological effects on the pathophysiology and treatment of diabetes. In this study, we analyzed the coevolution of insulin molecules among vertebrates, aiming at exploring the evolutionary characteristics of insulin molecule, especially the C-peptide. We also calculated the correlations of evolutionary rates between the insulin and the insulin receptor (IR) sequences as well as the domain-domain pairs of the ligand and receptor by the mirrortree method. The results revealed distinctive features of C-peptide in insulin intramolecular coevolution and correlated residue substitutions, which partly supported the idea that C-peptide can act as a bioactive hormone, with significant sequence features, as well as a linker assisting the formation of mature insulin during synthesis. Interestingly, the evolution of C-peptide exerted the highest correlation with that of the insulin receptor and its ligand binding domain (LBD), implying a potential relationship with the insulin signaling pathway.     

Tolerance induction by exosomes from immature dendritic cells and rapamycin in a mouse cardiac allograft model

Background

Dendritic cells (DCs) release bioactive exosomes that play an important role in immune regulation. Because they express low levels of class I major histocompatibility complex (MHC) and co-stimulatory molecules, exosomes derived from donor immature DCs (imDex) prolong allograft survival by inhibiting T-cell activation. However, this effect is limited and does not induce immunological tolerance when imDex are administered alone. Thus, we tested the effect of combined treatment with donor imDex and low-dose rapamycin on inducing tolerance in a mouse cardiac transplantation model.

Methods

ImDex were obtained from the culture supernatant of immature DCs derived from donor mouse (C57BL/6) bone marrow and were injected with suboptimal doses of rapamycin into recipient mouse (BALB/c) before and after transplantation. The capacity of this treatment to induce immune tolerance was analyzed in vitro and in vivo using the mouse cardiac transplantation model.

Results

Donor imDex expressed moderate levels of MHC class II and low levels of MHC class I and co-stimulatory molecules, but neither imDex nor subtherapeutic rapamycin dose alone induced cardiac allograft tolerance. Combined treatment with imDex and rapamycin, however, led to donor specific cardiac allograft tolerance. This effect was accompanied by decreased anti-donor antigen cellular response and an increased percentage of spleen CD4⁺CD25⁺ T cells in recipients. Furthermore, this donor specific tolerance could be further transferred to naïve allograft recipients through injection of splenocytes, but not serum, from tolerant recipients.

Conclusion

Combined with immunosuppressive treatment, donor imDex can prolong cardiac allograft survival and induce donor specific allograft tolerance.     

Inhibition of noroviruses by piperazine derivatives

There is currently an unmet need for the development of small-molecule therapeutics for norovirus infection. The piperazine scaffold, a privileged structure embodied in many pharmacological agents, was used to synthesize an array of structurally-diverse derivatives which were screened for anti-norovius activity in a cell-based replicon system. The studies described herein demonstrate for the first time that functionalized piperazine derivatives possess anti-norovirus activity. Furthermore, these studies have led to the identification of two promising compounds (6a and 9l) that can be used as a launching pad for the optimization of potency, cytotoxicity, and drug-like characteristics.     

Elemental signature in otolith nuclei for stock discrimination of anadromous tapertail anchovy (Coilia nasus) using laser ablation ICPMS

The elemental signature in otolith nuclei was determined using laser ablation inductively coupled plasma mass spectrometry (LA-ICPMS) for stock discrimination of adult anadromous tapertail anchovy, Coilia nasus, in five Chinese estuaries. Five elements (Na, Mg, K, Sr, and Ba) were well detected in the otolith nuclei of the adult fish. Results showed that the elemental composition in the otolith nuclei varied substantially among the estuaries. Age and fish length data showed no significant influences on the elemental concentration ratios across the sample sites. The Sr:Ca and Ba:Ca ratios were inter-site distinct and could be used as natal tags for discriminating among stocks. Discriminant function analyses (DFA) showed that these ratios can be used in discriminating the Liaohe River estuary (LD, 92.3?%), the Yangtze River estuary (CJ, 86.7?%), and the Yellow River estuary (HH, 76.9?%) samples with high classification accuracy, followed by the Haihe River estuary (BH, 58.3?%) and the Daguhe River estuary (JZ, 46.2?%) samples. An overall classification accuracy rate of 72.7?% from the discriminant functions indicated that elemental fingerprinting appeared to have the potential to discriminate between tapertail anchovy stocks in these estuaries.     

The migratory history of anadromous and non-anadromous tapertail anchovy Coilia nasus in the Yangtze River Estuary revealed by the otolith Sr:Ca ratio

The migratory history of tapertail anchovy Coilia nasus in the Yangtze River Estuary, China was investigated using otolith Sr:Ca ratios and two-dimensional images of the Sr level from an X-ray electron probe microanalyzer (EPMA). The results showed that 17 of the 22 young-of-the-year (YOY) specimens had low Sr:Ca ratios (1.2–2.4?×?10^?3;1.5?±?0.3?×?10^?3) at the central otolith area, indicating their riverine origin and initial freshwater residence. In addition, 11 of the 14 adult specimens had low Sr:Ca ratios (1.3–2.2?×?10^?3; 1.7?±?0.4?×?10^?3) at the central otolith area but showed alternating changes between high (>4.0?×?10^?3) and low (<2.5?×?10^?3) values outside of this region, reflecting their riverine origin and the migration between freshwater and estuarine habitats. These 28 specimens represented the anadromous population in this region. The other 5 YOY specimens had high Sr:Ca ratios (3.6–5.9?×?10^?3; 4.8?±?0.8?×?10^?3) throughout the life history. Similarly, the other 3 adult specimens had high Sr:Ca ratios (4.0–5.7?×?10^?3; 4.8?±?0.7?×?10^?3) at the central otolith area but showed alternating changes between low and high values outside this region, suggesting that estuarine-origin non-anadromous individuals occurred in this region. The average of the otolith Sr:Ca ratios and Sr level mapping along the life-history transects could be used as a scalar for charting the migratory history of the tapertail anchovy in the Yangtze River Estuary: <2.0?×?10^?3 for freshwater residence and 3.5–6.0?×?10^?3 for estuarine residence.     

MOLECULAR CHARACTERIZATIONS OF TWO CYTOCHROME P450 GENES ENCODING CYP6A41 AND CYP6EK1 FROM THE ORIENTAL FRUIT FLY,Bactrocera dorsalis (DIPTERA: TEPHRITIDAE)

Two P450 genes encoding CYP6A41 and CYP6EK1 were cloned from the oriental fruit fly using polymerase chain reaction (PCR) and rapid amplification of cDNA ends (RACE) techniques. CYP6A41 and CYP6EK1 contained open reading frames of 1,530 and 1,524 nucleotides that encode 510 and 508 amino acid residues, respectively. The putative proteins shared 44% identity with each other. Phylogenetic analysis showed that CYP6A41 and CYP6EK1 were most closely related to Ceratitis capitata CYP6A10 and CYP6A subfamily. Expression patterns of the two genes in different geographical populations (Yunnan, Hainan, Dongguang, and Guangzhou), developmental stages (eggs, larvae, pupae, and adults), and tissues (midguts, fat bodies, and Malpighian tubules) were analyzed by real‐time quantitative PCR (RT‐qPCR) methods. The results showed that the expression levels of CYP6EK1 were significantly different among the four populations, but were not different for CYP6A41. Both the expressions of CYP6A41 and CYP6EK1 were development specific and had significantly higher levels in the larval stage. The expression of CYP6A41 did not vary among the midgut, fat body, or Malpighian tubules; however, CYP6EK1 expression was higher in the Malpighian tubules. The results suggest that CYP6A41 and CYP6EK1 might be involved in detoxification of xenobiotic compounds that were harmful to larval flies or development. Moreover, high expression of CYP6EK1 in the Malpighian tubules also implied participation in detoxification.