Evaluating the relative importance of patch quality and connectivity in a damselfly metapopulation from a one-season survey

The area-and-isolation paradigm, which has been the primary focus of metapopulation research, may not hold in some animal metapopulations if within-patch preference is more important than patch area or connectivity. Recently, regression analyses have been used to evaluate the effect of patch connectivity and various patch qualities including area. However, their relative importance is not easy to determine, because patch qualities and connectivity are often spatially autocorrelated. In this paper, we try to evaluate the relative importance of within-patch quality, patch connectivity and spatial autocorrelation using variation partitioning methods from community ecology. We constructed three regression models: within-patch quality, PCNM (principal coordinates of neighbor matrices) and patch connectivity based on a one-season survey of a damselfly Copera annulata metapopulation. The contribution of within-patch quality was larger than that of connectivity. There was no prominent effect of patch area. We conclude that the area-and-isolation paradigm is not applicable to this C. annulata metapopulation. The spatial autocorrelation extracted by PCNM had the largest contribution; it contained almost all of the variation of connectivity and overlapped with variation explained by within-patch quality. Connectivity corresponded most closely to medium-scale spatial structure captured by PCNM (ca 640  m). The mean effective dispersal scale was estimated to be 53  m. Within-patch quality, debris accumulation and vegetation cover in the pond corresponded with the medium and small (ca 201  m) spatial scales from PCNM, though we could not clearly explain the cause of this correspondence. We believe that our method will contribute to quick and effective evaluation of spatial and non-spatial aspects of metapopulation.     

Immune cell types involved in early uptake and transport of recombinant mouse prion protein in Peyer’s patches of calves

We have previously reported the early uptake and transport of foreign particles into Peyer’s patches (PPs) of newborn and 2-month-old calves and shown that the peak uptake of particles occurs 6 h after inoculation, in addition to site- and size-related effects on particle uptake. We now report the distribution of immune cells within PPs of the distal ileum in newborn and 2-month-old calves inoculated with carbon black. The types of immune cells involved in the early uptake and transport of recombinant mouse prion protein (rMPrP) within PPs of newborn calf were investigated by using monoclonal antibodies CD11c, CD14, CD68, CD172a, and CD21. CD11c⁺, CD14⁺, CD68⁺, CD172a⁺, and CD21⁺ immune cells were widely distributed in four tissue compartments (villi, dome, interfollicular region, and follicles) of PPs in the distal ileum of newborn and 2-month-old calves, whereas CD11c⁺, CD14⁺, CD172a⁺, and CD21⁺ immune cells were more prominently distributed in the dome areas of newborn calves than in 2-month-old calves. Moreover, CD11c⁺ and CD14⁺ dendritic cells, CD172a⁺ and CD68⁺ macrophages, and CD21⁺ follicular dendritic cells containing rMPrP were primarily observed in the dome and inner follicular regions. The deposition of rMPrP within CD11c⁺, CD14⁺, CD172a⁺, and CD68⁺ cells, but not CD21⁺ cells, was detected in villous regions. rMPrP-positive immune cells within the interfollicular regions included only CD11c⁺ and CD172⁺ cells. Although the particles used in this investigation do not include the infectious prion protein, PrP^Sc, our experimental setup provides a useful model for studying immune cells involved in the early uptake and transport of PrP^Sc.     

Discovery of tetrahydrotetramethylnaphthalene analogs as adult T-cell leukemia cell-selective proliferation inhibitors in a small chemical library constructed based on multi-template hypothesis

Adult T cell leukemia (ATL), caused by infection of human T-lymphotropic virus type 1 (HTLV-1), has a poor prognosis and curative therapy is unavailable, so it is important to find or design superior lead compounds for the drug treatment of ATL. We used our micro-reversed fragment-based drug design hypothesis and multi-template hypothesis to extract the tetrahydrotetramethylnaphthalene (TMN) skeleton from tamibarotene, a useful medicament for the treatment of acute promyelocytic leukemia (APL). Structural development of TMN yielded highly ATL cell-selective growth inhibitors, including 2-acetyl-3-hydroxy-5,6,7,8-tetrahydro-5,5,8,8-tetramethylnaphthalene (6). Structure–activity relationship analysis suggests the existence of a specific target molecule for ATL cell-selective inhibition of proliferation through G2 arrest.     

Modulation of Local PtdIns3P Levels by the PI Phosphatase MTMR3 Regulates Constitutive Autophagy

Autophagy is a catabolic process that delivers cytoplasmic material to the lysosome for degradation. The mechanisms regulating autophagosome formation and size remain unclear. Here, we show that autophagosome formation was triggered by the overexpression of a dominant‐negative inactive mutant of Myotubularin‐related phosphatase 3 (MTMR3). Mutant MTMR3 partially localized to autophagosomes, and PtdIns3P and two autophagy‐related PtdIns3P‐binding proteins, GFP‐DFCP1 and GFP‐WIPI‐1α (WIPI49/Atg18), accumulated at sites of autophagosome formation. Knock‐down of MTMR3 increased autophagosome formation, and overexpression of wild‐type MTMR3 led to significantly smaller nascent autophagosomes and a net reduction in autophagic activity. These results indicate that autophagy initiation depends on the balance between PI 3‐kinase and PI 3‐phosphatase activity. Local levels of PtdIns3P at the site of autophagosome formation determine autophagy initiation and the size of the autophagosome membrane structure.     

Study on immunocapture-chemiluminescence assay of lipase activity in a biological sample.

A new approach for the determination of lipase (triacylglycerol lipase, EC.3.1.1.3) activity in a biological sample was investigated by combining an immunocapture technique with a chemiluminescence (CL) assay method in order to eliminate interference with CL detection. The proposed method consists of an immunocapture step to trap lipase and a subsequent step for CL detection of the activity of the captured lipase. The CL detection is based on the luminol-hydrogen peroxide (H(2)O(2))-horseradish peroxidase (HRP) reaction and utilizes a proenhancer substrate [a lauric acid ester of 2-(4-hydroxyphenyl)-4,5-diphenylimidazole (HDI)] which liberates an active enhancer, HDI, by enzymatic hydrolysis. A polyclonal antibody prepared with porcine pancreas lipase was used for the immunocapture. The proposed immunocapture-CL method effectively eliminated the interference with the CL reaction from biological components and enabled the determination of spiked porcine pancreas lipase activity in serum samples in the range 0.41-1.1 U(HDI) (1 U(HDI) corresponds to the amount which liberates 1 pmol HDI/min at 37 degrees C from the substrate). The method was further applied to the assay of the activity for human pancreas lipase in serum and the results showed good correlation (r = 0.871) with those by the conventional colorimetric method.     

Regulatory roles for APJ, a seven-transmembrane receptor related to angiotensin-type 1 receptor in blood pressure in vivo

APJ is a G-protein-coupled receptor with seven transmembrane domains, and its endogenous ligand, apelin, was identified recently. They are highly expressed in the cardiovascular system, suggesting that APJ is important in the regulation of blood pressure. To investigate the physiological functions of APJ, we have generated mice lacking the gene encoding APJ. The base-line blood pressure of APJ-deficient mice is equivalent to that of wild-type mice in the steady state. The administration of apelin transiently decreased the blood pressure of wild-type mice and a hypertensive model animal, a spontaneously hypertensive rat. On the other hand, this hypotensive response to apelin was abolished in APJ-deficient mice. This apelin-induced response was inhibited by pretreatment with a nitric-oxide synthase inhibitor, and apelin-induced phosphorylation of endothelial nitric-oxide synthase in lung endothelial cells from APJ-deficient mice disappeared. In addition, APJ-deficient mice showed an increased vasopressor response to the most potent vasoconstrictor angiotensin II, and the base-line blood pressure of double mutant mice homozygous for both APJ and angiotensin-type 1a receptor was significantly elevated compared with that of angiotensin-type 1a receptor-deficient mice. These results demonstrate that APJ exerts the hypotensive effect in vivo and plays a counterregulatory role against the pressor action of angiotensin II.     

Dendritic cells transduced with protein antigens induce cytotoxic lymphocytes and elicit antitumor immunity

Dendritic cell (DC)-based vaccines are being developed for treatment of patients with cancer, in part because DC are potent inducers of CD8(+) CTL. DC MHC class I:antigenic peptide complexes that are required for CTL elicitation are most often generated by incubating DC with peptides or by transfecting (or transducing) DC with cDNAs (or viral vectors) that encode protein Ags. The former approach is feasible when MHC class I Ags and relevant peptides are known. The latter approach may be hampered by inefficient DC transfection (transduction) and/or difficulties associated with preparation and use of viral vectors. Herein we demonstrate that a bacterial recombinant model tumor-associated Ag (OVA) that contains the HIV TAT protein transduction domain (PTD) was readily engineered and purified, efficiently transduced murine lymphocytes and DC, and was processed by proteasomes for MHC class I-restricted presentation to CTL. In addition, PTD-containing rOVA was processed and presented by DC to CD4 T cells as efficiently as native OVA or rOVA lacking the PTD. PTD-OVA-transduced DC induced CTL in vivo in a Th cell-independent fashion and vaccinated against OVA-expressing tumors. In contrast, rOVA lacking the PTD did not enter the DC MHC class I presentation pathway and DC treated with this protein did not prime OVA-specific CTL in vivo. Treatment of mice harboring clinically apparent OVA-expressing tumors with PTD-OVA-transduced DC resulted in tumor regression in some animals. This straightforward vaccination strategy may translate into DC-based treatments for patients with cancer and other serious diseases.