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941.
Griese Eddie Pineda Ana Pashalidou Foteini G. Iradi Eleonora Pizarro Hilker Monika Dicke Marcel Fatouros Nina E. 《Oecologia》2020,192(2):463-475
Oecologia - The preference–performance hypothesis (PPH) states that herbivorous female insects prefer to oviposit on those host plants that are best for their offspring. Yet, past attempts to... 相似文献
942.
Alvaro Ingles-Prieto Nikolas Furthmann Samuel H. Crossman Alexandra-Madelaine Tichy Nina Hoyer Meike Petersen Vanessa Zheden Julia Biebl Eva Reichhart Attila Gyoergy Daria E. Siekhaus Peter Soba Konstanze F. Winklhofer Harald Janovjak 《PLoS genetics》2021,17(4)
Optogenetics has been harnessed to shed new mechanistic light on current and future therapeutic strategies. This has been to date achieved by the regulation of ion flow and electrical signals in neuronal cells and neural circuits that are known to be affected by disease. In contrast, the optogenetic delivery of trophic biochemical signals, which support cell survival and are implicated in degenerative disorders, has never been demonstrated in an animal model of disease. Here, we reengineered the human and Drosophila melanogaster REarranged during Transfection (hRET and dRET) receptors to be activated by light, creating one-component optogenetic tools termed Opto-hRET and Opto-dRET. Upon blue light stimulation, these receptors robustly induced the MAPK/ERK proliferative signaling pathway in cultured cells. In PINK1B9 flies that exhibit loss of PTEN-induced putative kinase 1 (PINK1), a kinase associated with familial Parkinson’s disease (PD), light activation of Opto-dRET suppressed mitochondrial defects, tissue degeneration and behavioral deficits. In human cells with PINK1 loss-of-function, mitochondrial fragmentation was rescued using Opto-dRET via the PI3K/NF-кB pathway. Our results demonstrate that a light-activated receptor can ameliorate disease hallmarks in a genetic model of PD. The optogenetic delivery of trophic signals is cell type-specific and reversible and thus has the potential to inspire novel strategies towards a spatio-temporal regulation of tissue repair. 相似文献
943.
Nina Seidelmann Daniela F. Duarte Campos Malena Rohde Sandra Johnen Sabine Salla Gary Hin-Fai Yam Jodhbir S. Mehta Peter Walter Matthias Fuest 《Journal of cellular and molecular medicine》2021,25(20):9647-9659
The isolation and propagation of primary human corneal stromal keratocytes (CSK) are crucial for cellular research and corneal tissue engineering. However, this delicate cell type easily transforms into stromal fibroblasts (SF) and scar inducing myofibroblasts (Myo-SF). Current protocols mainly rely on xenogeneic fetal bovine serum (FBS). Human platelet lysate (hPL) could be a viable, potentially autologous, alternative. We found high cell survival with both supplements in CSK and SF. Cell numbers and Ki67+ ratios increased with higher fractions of hPL and FBS in CSK and SF. We detected a loss in CSK marker expression (Col8A2, ALDH3A1 and LUM) with increasing fractions of FBS and hPL in CSK and SF. The expression of the Myo-SF marker SMA increased with higher amounts of FBS but decreased with incremental hPL substitution in both cell types, implying an antifibrotic effect of hPL. Immunohistochemistry confirmed the RT-PCR findings. bFGF and HGF were only found in hPL and could be responsible for suppressing the Myo-SF conversion. Considering all findings, we propose 0.5% hPL as a suitable substitution in CSK culture, as this xeno-free component efficiently preserved CSK characteristics, with non-inferiority in terms of cell viability, cell number and proliferation in comparison to the established 0.5% FBS protocol. 相似文献
944.
945.
Heterotrimeric G proteins of the Gq/11 family are crucial for the induction of maternal behavior in mice 下载免费PDF全文
Wettschureck N Moers A Hamalainen T Lemberger T Schütz G Offermanns S 《Molecular and cellular biology》2004,24(18):8048-8054
Heterotrimeric G proteins of the G(q/11) family transduce signals from a variety of neurotransmitter receptors and have therefore been implicated in several functions of the central nervous system. To investigate the potential role of G(q/11) signaling in behavior, we generated mice which lack the alpha-subunits of the two main members of the G(q/11) family, Galpha(q) and Galpha(11), selectively in the forebrain. We show here that forebrain Galpha(q/11)-deficient females do not display any maternal behavior such as nest building, pup retrieving, crouching, or nursing. However, olfaction, motor behavior and mammary gland function are normal in forebrain Galpha(q/11)-deficient females. We used c-fos immunohistochemistry to investigate pup-induced neuronal activation in different forebrain regions and found a significant reduction in the medial preoptic area, the bed nucleus of stria terminalis, and the lateral septum both in postpartum females and in virgin females after foster pup exposure. Pituitary function, especially prolactin release, was normal in forebrain Galpha(q/11)-deficient females, and activation of oxytocin receptor-positive neurons in the hypothalamus did not differ between genotypes. Our findings show that G(q/11) signaling is indispensable to the neuronal circuit that connects the perception of pup-related stimuli to the initiation of maternal behavior and that this defect cannot be attributed to either reduced systemic prolactin levels or impaired activation of oxytocin receptor-positive neurons of the hypothalamus. 相似文献
946.
In vitro adhesion specificity of indigenous Lactobacilli within the avian intestinal tract 总被引:1,自引:0,他引:1
Edelman S Westerlund-Wikström B Leskelä S Kettunen H Rautonen N Apajalahti J Korhonen TK 《Applied and environmental microbiology》2002,68(10):5155-5159
In vitro adherence of Lactobacillus strains to cell and tissue types along the chicken alimentary tract and to ileal mucus were determined. Fresh isolates from chickens adhered to the epithelium of crop and, in a strain-dependent manner, to follicle-associated epithelium and the apical surfaces of mature enterocytes of intestinal villi. No adherence to the apical surfaces of undifferentiated enterocytes, the mucus-producing goblet cells, or the ileal mucus was detected. 相似文献
947.
Wang D Visser NV Veenhuis M van der Klei IJ 《The Journal of biological chemistry》2003,278(44):43340-43345
We have studied Hansenula polymorpha Pex5p and Pex8p using fluorescence correlation spectroscopy (FCS). Pex5p is the Peroxisomal Targeting Signal 1 (PTS1) receptor and Pex8p is an intraperoxisomal protein. Both proteins are essential for PTS1 protein import and have been shown to physically interact. We used FCS to analyze the molecular role of this interaction. FCS is a very sensitive technique that allows analysis of dynamic processes of fluorescently marked molecules at equilibrium in a very tiny volume. We used this technique to determine the oligomeric state of both peroxins and to analyze binding of Pex5p to PTS1 peptides and Pex8p. HpPex5p and HpPex8p were overproduced in Escherichia coli, purified by affinity chromatography, and, when required, labeled with the fluorescent dye Alexa Fluor 488. FCS measurements revealed that the oligomeric state of HpPex5p varied, ranging from monomers at slightly acidic pH to tetramers at neutral pH. HpPex8p formed monomers at all pH values tested. Using fluorescein-labeled PTS1 peptide and unlabeled HpPex5p, we established that PTS1 peptide only bound to tetrameric HpPex5p. Upon addition of HpPex8p, a heterodimeric complex was formed consisting of one HpPex8p and one HpPex5p molecule. This process was paralleled by dissociation of PTS1 peptide from HpPex5p, indicating that Pex8p may play an important role in cargo release from the PTS1 receptor. Our data show that FCS is a powerful technique to explore dynamic physical interactions that occur between peroxins during peroxisomal matrix protein import. 相似文献
948.
Kalderon B Mayorek N Ben-Yaacov L Bar-Tana J 《American journal of physiology. Endocrinology and metabolism》2003,284(4):E795-E803
The putative role played by insulin sensitizers in modulating adipose tissue lipolysis in the fasting state was evaluated in obese conscious Zucker rats treated with troglitazone or beta,beta'-tetramethylhexadecanedioic acid (MEDICA 16) and compared with nontreated lean and obese animals. The rates of appearance (R(a)) of glycerol and free fatty acid (FFA), primary intra-adipose reesterification, and secondary reuptake of plasma FFA in adipose fat were measured using constant infusion of stable isotope-labeled [(2)H(5)]glycerol, [2,2-(2)H(2)]palmitate, and radioactive [(3)H]palmitate. The overall lipolytic flux (R(a) glycerol) was increased 1.7- and 1.4-fold in obese animals treated with troglitazone or MEDICA 16, respectively, resulting in increased FFA export (R(a) FFA) in the troglitazone-treated rats. Primary intra-adipose reesterification of lipolysis-derived fatty acids was enhanced twofold by insulin sensitizers, whereas reesterification of plasma fatty acids was unaffected by either treatment. Despite the unchanged R(a) FFA in MEDICA 16 or the increased R(a) FFA induced by troglitazone, very low density lipoprotein production rates were robustly curtailed. Total adipose tissue reesterification, used as an estimate of glucose conversion to glyceride-glycerol, was increased 1.9-fold by treatment with the insulin sensitizers. Our results indicate that, in the fasting state, insulin sensitizers induce, in vivo, a significant activation rather than suppression of adipose tissue lipolysis together with stimulation of glucose conversion to glyceride-glycerol. 相似文献
949.
Plant volatiles induced by herbivore egg deposition affect insects of different trophic levels 总被引:1,自引:0,他引:1
NE Fatouros D Lucas-Barbosa BT Weldegergis FG Pashalidou JJ van Loon M Dicke JA Harvey R Gols ME Huigens 《PloS one》2012,7(8):e43607
Plants release volatiles induced by herbivore feeding that may affect the diversity and composition of plant-associated arthropod communities. However, the specificity and role of plant volatiles induced during the early phase of attack, i.e. egg deposition by herbivorous insects, and their consequences on insects of different trophic levels remain poorly explored. In olfactometer and wind tunnel set-ups, we investigated behavioural responses of a specialist cabbage butterfly (Pieris brassicae) and two of its parasitic wasps (Trichogramma brassicae and Cotesia glomerata) to volatiles of a wild crucifer (Brassica nigra) induced by oviposition of the specialist butterfly and an additional generalist moth (Mamestra brassicae). Gravid butterflies were repelled by volatiles from plants induced by cabbage white butterfly eggs, probably as a means of avoiding competition, whereas both parasitic wasp species were attracted. In contrast, volatiles from plants induced by eggs of the generalist moth did neither repel nor attract any of the tested community members. Analysis of the plant's volatile metabolomic profile by gas chromatography-mass spectrometry and the structure of the plant-egg interface by scanning electron microscopy confirmed that the plant responds differently to egg deposition by the two lepidopteran species. Our findings imply that prior to actual feeding damage, egg deposition can induce specific plant responses that significantly influence various members of higher trophic levels. 相似文献
950.
Gubsch M Roscher C Gleixner G Habekost M Lipowsky A Schmid B Schulze ED Steinbeiss S Buchmann N 《Plant, cell & environment》2011,34(6):895-908
Plant and soil nitrogen isotope ratios (δ15N) were studied in experimental grassland plots of varying species richness. We hypothesized that partitioning of different sources of soil nitrogen among four plant functional groups (legumes, grasses, small herbs, tall herbs) should increase with diversity. Four years after sowing, all soils were depleted in 15N in the top 5 cm whereas in non‐legume plots soils were enriched in 15N at 5–25 cm depth. Decreasing foliar δ15N and Δδ15N (= foliar δ15N ? soil δ15N) values in legumes indicated increasing symbiotic N2 fixation with increasing diversity. In grasses, foliar Δδ15N also decreased with increasing diversity suggesting enhanced uptake of N depleted in 15N. Foliar Δδ15N values of small and tall herbs were unaffected by diversity. Foliar Δδ15N values of grasses were also reduced in plots containing legumes, indicating direct use of legume‐derived N depleted in 15N. Increased foliar N concentrations of tall and small herbs in plots containing legumes without reduced foliar δ15N indicated that these species obtained additional mineral soil N that was not consumed by legumes. These functional group and species specific shifts in the uptake of different N sources with increasing diversity indicate complementary resource use in diverse communities. 相似文献