Molecular Portrait of Human Kidney Carcinomas: The cDNA Microarray Profiling of Kinases and Phosphatases Involved in the Cell Signaling Control

Hybridization with cDNA arrays was used to obtain expression profiles of 214 protein-tyrosine kinase, protein-tyrosine phosphatase, dual specificity phosphatase, and other genes for kidney carcinomas (KC) and normal kidney tissues of 34 patients and for seven carcinoma cell lines. Computer analysis revealed three clusters of genes coexpressed in KC. The proliferating-cell gene cluster included MET, VIM, MYC, TOP2A, PCNA. The neoangiogenesis and blood-cell gene cluster included LCK, HCK, FGR, MMP9, CSFR1, VEGF, FLT1, and KDR. The cluster corresponding to normal, differentiated kidney cells included ERBB2 (HER2) for receptor protein-tyrosine kinase, several phosphatase genes (PTPRE, PTPRB, DUSP9), and EGF. The results suggested that MET, DUSP9, PCNA, TOP2A, and VIM may serve as diagnostic and prognostic markers in KC. Tubulin and topoisomerase II were assumed to be promising targets for cell proliferation inhibitors in KC.     

A novel ovary-specific and ovulation-associated variant of epoxide hydrolase 2

Ovulation is a complex process initiated by the surge of the pituitary luteinizing hormone (LH) that provokes the expression of specific genes. We report herein the isolation and characterization of an ovulation-associated, ovary-specific novel isoform of epoxide hydrolase 2 (Ephx2), Ephx2C. This variant is exclusively expressed in the granulosa cells of preovulatory mouse ovarian follicles. The LH-induced expression of Ephx2C is mediated by the protein kinase A and partially by the protein kinase C signaling pathways. The involvement of p38 kinase has also been demonstrated.     

ABI4 downregulates expression of the sodium transporter HKT1;1 in Arabidopsis roots and affects salt tolerance

A plant's ability to cope with salt stress is highly correlated with their ability to reduce the accumulation of sodium ions in the shoot. Arabidopsis mutants affected in the ABSCISIC ACID INSENSITIVE (ABI) 4 gene display increased salt tolerance, whereas ABI4‐overexpressors are hypersensitive to salinity from seed germination to late vegetative developmental stages. In this study we demonstrate that abi4 mutant plants accumulate lower levels of sodium ions and higher levels of proline than wild‐type plants following salt stress. We show higher HKT1;1 expression in abi4 mutant plants and lower levels of expression in ABI4‐overexpressing plants, resulting in reduced accumulation of sodium ions in the shoot of abi4 mutants. HKT1;1 encodes a sodium transporter which is known to unload sodium ions from the root xylem stream into the xylem parenchyma stele cells. We have shown recently that ABI4 is expressed in the root stele at various developmental stages and that it plays a key role in determining root architecture. Thus ABI4 and HKT1;1 are expressed in the same cells, which suggests the possibility of direct binding of ABI4 to the HKT1;1 promoter. In planta chromatin immunoprecipitation and in vitro electrophoresis mobility shift assays demonstrated that ABI4 binds two highly related sites within the HKT1;1 promoter. These sites, GC(C/G)GCTT(T), termed ABI4‐binding element (ABE), have also been identified in other ABI4‐repressed genes. We therefore suggest that ABI4 is a major modulator of root development and function.     

Reactive Oxygen Species Tune Root Tropic Responses

The default growth pattern of primary roots of land plants is directed by gravity. However, roots possess the ability to sense and respond directionally to other chemical and physical stimuli, separately and in combination. Therefore, these root tropic responses must be antagonistic to gravitropism. The role of reactive oxygen species (ROS) in gravitropism of maize and Arabidopsis (Arabidopsis thaliana) roots has been previously described. However, which cellular signals underlie the integration of the different environmental stimuli, which lead to an appropriate root tropic response, is currently unknown. In gravity-responding roots, we observed, by applying the ROS-sensitive fluorescent dye dihydrorhodamine-123 and confocal microscopy, a transient asymmetric ROS distribution, higher at the concave side of the root. The asymmetry, detected at the distal elongation zone, was built in the first 2 h of the gravitropic response and dissipated after another 2 h. In contrast, hydrotropically responding roots show no transient asymmetric distribution of ROS. Decreasing ROS levels by applying the antioxidant ascorbate, or the ROS-generation inhibitor diphenylene iodonium attenuated gravitropism while enhancing hydrotropism. Arabidopsis mutants deficient in Ascorbate Peroxidase 1 showed attenuated hydrotropic root bending. Mutants of the root-expressed NADPH oxidase RBOH C, but not rbohD, showed enhanced hydrotropism and less ROS in their roots apices (tested in tissue extracts with Amplex Red). Finally, hydrostimulation prior to gravistimulation attenuated the gravistimulated asymmetric ROS and auxin signals that are required for gravity-directed curvature. We suggest that ROS, presumably H₂O₂, function in tuning root tropic responses by promoting gravitropism and negatively regulating hydrotropism.Plants evolved the ability to sense and respond to various environmental stimuli in an integrated fashion. Due to their sessile nature, they respond to directional stimuli such as light, gravity, touch, and moisture by directional organ growth (curvature), a phenomenon termed tropism. Experiments on coleoptiles conducted by Darwin in the 1880s revealed that in phototropism, the light stimulus is perceived by the tip, from which a signal is transmitted to the growing part (Darwin and Darwin, 1880). Darwin postulated that in a similar manner, the root tip perceives stimuli from the environment, including gravity and moisture, processes them, and directs the growth movement, acting like “the brain of one of the lower animals” (Darwin and Darwin, 1880). The transmitted signal in phototropism and gravitropism was later found to be a phytohormone, and its redistribution on opposite sides of the root or shoot was hypothesized to promote differential growth and bending of the organ (Went, 1926; Cholodny, 1927). Over the years, the phytohormone was characterized as indole-3-acetic acid (IAA, auxin; Kögl et al., 1934; Thimann, 1935), and the ‘Cholodny-Went’ theory was demonstrated for gravitropism and phototropism (Rashotte et al., 2000; Friml et al., 2002). In addition to auxin, second messengers such as Ca²⁺, pH oscillations, reactive oxygen species (ROS) and abscisic acid (ABA) were shown to play an essential role in gravitropism (Young and Evans, 1994; Fasano et al., 2001; Joo et al., 2001; Ponce et al., 2008). Auxin was shown to induce ROS accumulation during root gravitropism, where the gravitropic bending is ROS dependent (Joo et al., 2001; Peer et al., 2013).ROS such as superoxide and hydrogen peroxide were initially considered toxic byproducts of aerobic respiration but currently are known also for their essential role in myriad cellular and physiological processes in animals and plants (Mittler et al., 2011). ROS and antioxidants are essential components of plant cell growth (Foreman et al., 2003), cell cycle control, and shoot apical meristem maintenance (Schippers et al., 2016) and play a crucial role in protein modification and cellular redox homeostasis (Foyer and Noctor, 2005). ROS function as signal molecules by mediating both biotic- (Sagi and Fluhr, 2006; Miller et al., 2009) and abiotic- (Kwak et al., 2003; Sharma and Dietz, 2009) stress responses. Joo et al. (2001) reported a transient increase in intracellular ROS concentrations early in the gravitropic response, at the concave side of maize roots, where auxin concentrations are higher. Indeed, this asymmetric ROS distribution is required for gravitropic bending, since maize roots treated with antioxidants, which act as ROS scavengers, showed reduced gravitropic root bending (Joo et al., 2001). The link between auxin and ROS production was later shown to involve the activation of NADPH oxidase, a major membrane-bound ROS generator, via a PI3K-dependent pathway (Brightman et al., 1988; Joo et al., 2005; Peer et al., 2013). Peer et al. (2013) suggested that in gravitropism, ROS buffer auxin signaling by oxidizing the active auxin IAA to the nonactive and nontransported form, oxIAA.Gravitropic-oriented growth is the default growth program of the plant, with shoots growing upwards and roots downward. However, upon exposure to specific external stimuli, the plant overcomes its gravitropic growth program and bends toward or away from the source of the stimulus. For example, as roots respond to physical obstacles or water deficiency. The ability of roots to direct their growth toward environments of higher water potential was described by Darwin and even earlier and was later defined as hydrotropism (Von Sachs, 1887; Jaffe et al., 1985; Eapen et al., 2005).In Arabidopsis (Arabidopsis thaliana), wild-type seedlings respond to moisture gradients (hydrostimulation) by bending their primary roots toward higher water potential. Upon hydrostimulation, amyloplasts, the starch-containing plastids in root-cap columella cells, which function as part of the gravity sensing system, are degraded within hours and recover upon water replenishment (Takahashi et al., 2003; Ponce et al., 2008; Nakayama et al., 2012). Moreover, mutants with a reduced response to gravity (pgm1) and to auxin (axr1 and axr2) exhibit higher responsiveness to hydrostimulation, manifested as accelerated bending compared to wild-type roots (Takahashi et al., 2002, 2003). Recently, we have shown that hydrotropic root bending does not require auxin redistribution and is accelerated in the presence of auxin polar transport inhibitors and auxin-signaling antagonists (Shkolnik et al., 2016). These results reflect the competition, or interference, between root gravitropism and hydrotropism (Takahashi et al., 2009). However, which cellular signals participate in the integration of the different environmental stimuli that direct root tropic curvature is still poorly understood. Here we sought to assess the potential role of ROS in regulating hydrotropism and gravitropism in Arabidopsis roots.     

Cardiac shock-wave therapy in the treatment of coronary artery disease: systematic review and meta-analysis

Aim

To systematically review currently available cardiac shock-wave therapy (CSWT) studies in humans and perform meta-analysis regarding anti-anginal efficacy of CSWT.

Methods

The Cochrane Controlled Trials Register, Medline, Medscape, Research Gate, Science Direct, and Web of Science databases were explored. In total 39 studies evaluating the efficacy of CSWT in patients with stable angina were identified including single arm, non- and randomized trials. Information on study design, subject’s characteristics, clinical data and endpoints were obtained. Assessment of publication risk of bias was performed and heterogeneity across the studies was calculated by using random effects model.

Results

Totally, 1189 patients were included in 39 reviewed studies, with 1006 patients treated with CSWT. The largest patient sample of single arm study consisted of 111 patients. All selected studies demonstrated significant improvement in subjective measures of angina symptoms and/or quality of life, in the majority of studies left ventricular function and myocardial perfusion improved. In 12 controlled studies with 483 patients included (183 controls) angina class, Seattle Angina Questionnaire (SAQ) score, nitrates consumption were significantly improved after the treatment.In 593 participants across 22 studies the exercise capacity was significantly improved after CSWT, as compared with the baseline values (in meta-analysis standardized mean difference SMD?=??0.74; 95% CI, ?0.97 to ?0.5; p?<?0.001).

Conclusions

Systematic review of CSWT studies in stable coronary artery disease (CAD) demonstrated consistent improvement of clinical variables. Meta-analysis showed a moderate improvement of exercise capacity.Overall, CSWT is a promising non-invasive option for patients with end-stage CAD, but evidence is limited to small sample single-center studies. Multi-center adequately powered randomised double blind studies are warranted.

     

Interplay between abiotic (drought) and biotic (virus) stresses in tomato plants

With climate warming, drought becomes a vital challenge for agriculture. Extended drought periods affect plant–pathogen interactions. We demonstrate an interplay in tomato between drought and infection with tomato yellow leaf curl virus (TYLCV). Infected plants became more tolerant to drought, showing plant readiness to water scarcity by reducing metabolic activity in leaves and increasing it in roots. Reallocation of osmolytes, such as carbohydrates and amino acids, from shoots to roots suggested a role of roots in protecting infected tomatoes against drought. To avoid an acute response possibly lethal for the host organism, TYLCV down-regulated the drought-induced activation of stress response proteins and metabolites. Simultaneously, TYLCV promoted the stabilization of osmoprotectants' patterns and water balance parameters, resulting in the development of buffering conditions in infected plants subjected to prolonged stress. Drought-dependent decline of TYLCV amounts was correlated with HSFA1-controlled activation of autophagy, mostly in the roots. The tomato response to combined drought and TYLCV infection points to a mutual interaction between the plant host and its viral pathogen.     

Microbial digestion in the herbivorous lizard Uromastyx aegyptius (Agamidae)

The utilization of a diet rich in plant cell walls was studied in a large, desert-dwelling, herbivorous lizard, Uromastyx aegyptius (Agamidae). The diet eaten by U. aegyptius in spring in the 'Arava Valley, Israel, consisted almost entirely of leaves and fruits of short-lived annual plant species. The leaves contained only moderate levels of fibre compared with grasses and tree leaves, but those fruits eaten were markedly higher in fibre and lignin. All items had notably high contents of ash.
Following oral doses of [¹⁴C] cellulose, ¹⁴CO₂ was detected in respired air from U. aegyptius , demonstrating that the cellulose was digested and that the lizards gained oxidative energy from cellulose degradation. The hind gut was the principal site of microbial activity and the apparent digestibility of the cell-wall fraction was 69%. Similarly, the caecum/proximal colon had the highest concentrations of SCFA (76–120 mM).
The mean rate of SCFA production at 40 C in vitro was 31 mmol/1 h^-1. Assuming that this is representative of daily production rate, 69 kJ/kg d^-1 would be made available to the animal. This is 47% of the mean digestible energy intake estimated in free-living animals. Microbial fermentation contributes an important part of the energy budget of U. aegyptius but the effects of variation in body temperature on digestion and fermentation need further consideration.