Normal human adipose tissue functions and differentiation in patients with biallelic LPIN1 inactivating mutations

Lipin-1 is a Mg²⁺-dependent phosphatidic acid phosphatase (PAP) that in mice is necessary for normal glycerolipid biosynthesis, controlling adipocyte metabolism, and adipogenic differentiation. Mice carrying inactivating mutations in the Lpin1 gene display the characteristic features of human familial lipodystrophy. Very little is known about the roles of lipin-1 in human adipocyte physiology. Apparently, fat distribution and weight is normal in humans carrying LPIN1 inactivating mutations, but a detailed analysis of adipose tissue appearance and functions in these patients has not been available so far. In this study, we performed a systematic histopathological, biochemical, and gene expression analysis of adipose tissue biopsies from human patients harboring LPIN1 biallelic inactivating mutations and affected by recurrent episodes of severe rhabdomyolysis. We also explored the adipogenic differentiation potential of human mesenchymal cell populations derived from lipin-1 defective patients. White adipose tissue from human LPIN1 mutant patients displayed a dramatic decrease in lipin-1 protein levels and PAP activity, with a concomitant moderate reduction of adipocyte size. Nevertheless, the adipose tissue develops without obvious histological signs of lipodystrophy and with normal qualitative composition of storage lipids. The increased expression of key adipogenic determinants such as SREBP1, PPARG, and PGC1A shows that specific compensatory phenomena can be activated in vivo in human adipocytes with deficiency of functional lipin-1.     

SLC1A3 promotes gastric cancer progression via the PI3K/AKT signalling pathway

Gastric cancer is a major cause of mortality worldwide. The glutamate/aspartate transporter SLC1A3 has been implicated in tumour metabolism and progression, but the roles of SLC1A3 in gastric cancer remain unclear. We used bioinformatics approaches to analyse the expression of SLC1A3 and its role in gastric cancer. The expression levels of SLC1A3 were examined using RT‐qPCR and Western bolting. SLC1A3 overexpressing and knock‐down cell lines were constructed, and the cell viability was evaluated. Glucose consumption, lactate excretion and ATP levels were determined. The roles of SLC1A3 in tumour growth were evaluated using a xenograft tumour growth model. SLC1A3 was found to be overexpressed in gastric cancer, and this overexpression was associated with poor prognosis. In vitro and in vivo assays showed that SLC1A3 affected glucose metabolism and promoted gastric cancer growth. GSEA analysis suggested that SLC1A3 was positively associated with the up‐regulation of the PI3K/AKT pathway. SLC1A3 overexpression activated the PI3K/AKT pathway and up‐regulated GLUT1, HK II and LDHA expression. The PI3K/AKT inhibitor LY294002 prevented SLC1A3‐induced glucose metabolism and cell proliferation. Our findings indicate that SLC1A3 promotes gastric cancer progression via the PI3K/AKT signalling pathway. SLC1A3 is therefore a potential therapeutic target in gastric cancer.     

Characterization of human-dog social interaction using owner report

Dog owners were surveyed for observations of social behaviors in their dogs, using questions adapted from the human Autism Diagnostic Observation Schedule (ADOS) pre-verbal module. Using 939 responses for purebred and mixed-breed dogs, three factors were identified: initiation of reciprocal social behaviors (INIT), response to social interactions (RSPNS), and communication (COMM). There were small or no effects of sex, age, breed group or training. For six breeds with more than 35 responses (Border Collie, Rough Collie, German Shepherd, Golden Retriever, Labrador Retriever, Standard Poodle), the behaviors eye contact with humans, enjoyment in interactions with human interaction, and name recognition demonstrated little variability across breeds, while asking for objects, giving/showing objects to humans, and attempts to direct humans’ attention showed higher variability across these breeds. Breeds with genetically similar backgrounds had similar response distributions for owner reports of dog response to pointing. When considering these breeds according to the broad categories of “herders” and “retrievers,” owners reported that the “herders” used more eye contact and vocalization, while the “retrievers” used more body contact. Information regarding social cognitive abilities in dogs provided by owner report suggest that there is variability across many social cognitive abilities in dogs and offers direction for further experimental investigations.     

Studies of the ADP/ATP carrier of mitochondria with fluorescent ADP analogue formycin diphosphate

The ADP/ATP carrier was studied by a fluorescent substrate, formycin diphosphate which is the only fluorescent ADP analogue to bind. Its low quantum yield, short decay time and spectral overlap with tryptophan has as yet prevented its wider use.By incorporating fluorescent acceptors of formycin diphosphate fluorescence, anthracene-maleimide and vinylanthracene, into the membrane, these difficulties were circumvented. Only bound formycin diphosphate transfers energy to the probes so that the secondary emission of these probes is a measure for membrane-bound formycin diphosphate.The fluorescent transfer is inhibited by ADP, bongkrekate and carboxy-atractylate whether added before or after incubation of formycin diphosphate showing that only binding to the adenine nucleotide carrier is measured. It also shows directly that the earlier demonstrated ADP fixation by bongkrekate is indeed a displacement into the matrix.The fluorescence decay time of the bound formycin diphosphate is measured as 1.95 ns compared to 0.95 ns of the free formycin diphosphate, indicating that formycin diphosphate is bound at the carrier in a non-polar environment.The depolarization decay time was found to be larger than 15 ns, indicating that carrier-bound formycin diphosphate is immobile within this time period.     

Permeability of the foetal capillary endothelium of the guinea-pig placenta to haem proteins of various molecular sizes

Summary Haem proteins of different molecular sizes were perfused into the foetal circulation of the guinea-pig placenta to study the permeability of the foetal endothelium.The smallest molecules tested, microperoxidase (a_e 1.0 nm) and cytochrome C (a_e 1.5 nm), readily penetrated the endothelium; tracer-reaction product was found in the subendothelial space of the capillaries. However, there was no uptake of these two tracers into the syncytiotrophoblast layer of the placenta. An intermediate-sized molecule, myoglobin (a_e 1.7 nm), produced only a weak reaction product in the subendothelial space even when perfused at high concentration. The largest molecule tested, haemoglobin (a_e 2.8 nm), did not penetrate the foetal endothelium at any of the concentrations employed.The foetal capillary endothelium thus provided a barrier to protein penetration from the foetal circulation, dependent on molecular size. There was evidence that the site of this barrier was located in the lateral intercellular spaces between the endothelial cells.The syncytiotrophoblast of this haemomonochorial placenta provided an almost absolute barrier to protein penetration from the foetal circulation. As other workers have described maternal-to-foetal transmission of proteins across this layer in the guinea-pig, a working hypothesis of the role of endothelium and syncytiotrophoblast in maternal/foetal protein exchange is discussed.     

Root development in winter wheat grown at different N/P supply: Root length patterns and N-P interactions in phosphate uptake

Effects of different N/P ratios on several root parameters and on net P uptake were studied in winter wheat, Triticum aestivum cv. Starke II, grown in water culture. In the First experiment N/P ratios of (0/4, 2/3, 4/2, 6/1 and 8/0) were used, and plants were harvested at age 3, 5, 8, 11 and 14 days. In the second experiment N/P ratios of 6/1, 10/1, 15/1, 17/1, 20/1 and 25/1 were applied at two different N,P levels. Root length and number were determined using a digitizer connected to a computer. In the first experiment. the 6/1 N/P ratio gave the largest plants at day 14, and growth decreased with decreasing N/P ratio, The same pattern was found fur lateral root length and root number (seminal and lateral). In the second experiment the root weights decreased with increasing N/P ratio within each level. Lateral root number and overall length decreased with increasing N/P ratio at both levels as did the average lateral root length at the high N,P level. At the low N.P level, average lateral root length was about the same at all N/P ratios. Increasing the N/P ratio increased net uptake of P at the low N,P level, but decreased net P uptake at the high N,P level. Net P uptake increased with increasing P concentration in the roots and then decreased with further increase in P concentration. Net P uptake based on calculated root length [m (g root)⁻¹] showed no significant deviation from weight-based uptake plots. The effect of N and P on root structure is discussed as well as the interaction of N and P in P uptake. The relevance of a proper basis for expressing root activity is stressed.     

The arbitrium system controls prophage induction

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Anticancer effects of melatonin via regulating lncRNA JPX-Wnt/β-catenin signalling pathway in human osteosarcoma cells

Osteosarcoma (OS) is a type of malignant primary bone cancer, which is highly aggressive and occurs more commonly in children and adolescents. Thus, novel potential drugs and therapeutic methods are urgently needed. In the present study, we aimed to elucidate the effects and mechanism of melatonin on OS cells to provide a potential treatment strategy for OS. The cell survival rate, cell viability, proliferation, migration, invasion and metastasis were examined by trypan blue assay, MTT, colony formation, wound healing, transwell invasion and attachment/detachment assay, respectively. The expression of relevant lncRNAs in OS cells was determined by real-time qPCR analysis. The functional roles of lncRNA JPX in OS cells were further examined by gain and loss of function assays. The protein expression was measured by western blot assay. Melatonin inhibited the cell viability, proliferation, migration, invasion and metastasis of OS cells (Saos-2, MG63 and U2OS) in a dose-dependent manner. Melatonin treatment significantly downregulated the expression of lncRNA JPX in Saos-2, MG63 and U2OS cells. Overexpression of lncRNA JPX into OS cell lines elevated the cell viability and proliferation, which was accompanied by the increased metastasis. We also found that melatonin inhibited the OS progression by suppressing the expression of lncRNA JPX via regulating the Wnt/β-catenin pathway. Our results suggested that melatonin inhibited the biological functions of OS cells by repressing the expression of lncRNA JPX through regulating the Wnt/β-catenin signalling pathway, which indicated that melatonin might be applied as a potentially useful and effective natural agent in the treatment of OS.     

The Disordered Spindly C-terminus Interacts with RZZ Subunits ROD-1 and ZWL-1 in the Kinetochore through the Same Sites in C. Elegans

Spindly is a dynein adaptor involved in chromosomal segregation during cell division. While Spindly's N-terminal domain binds to the microtubule motor dynein and its activator dynactin, the C-terminal domain (Spindly-C) binds its cargo, the ROD/ZW10/ZWILCH (RZZ) complex in the outermost layer of the kinetochore. In humans, Spindly-C binds to ROD, while in C. elegans Spindly-C binds to both Zwilch (ZWL-1) and ROD-1. Here, we employed various biophysical techniques to characterize the structure, dynamics and interaction sites of C. elegans Spindly-C. We found that despite the overall disorder, there are two regions with variable α-helical propensity. One of these regions is located in the C-terminal half and is compact; the second is sparsely populated in the N-terminal half. The interactions with both ROD-1 and ZWL-1 are mostly mediated by the same two sequentially remote disordered segments of Spindly-C, which are C-terminally adjacent to the helical regions. The findings suggest that the Spindly-C binding sites on ROD-1 in the ROD-1/ZWL-1 complex context are either shielded or conformationally weakened by the presence of ZWL-1 such that only ZWL-1 directly interacts with Spindly-C in C. elegans