Solving post-prandial reduction in performance by adaptive regurgitation in a freshwater fish

Foraging animals must balance benefits of food acquisition with costs induced by a post-prandial reduction in performance. Eating to satiation can lead to a reduction in locomotor and escape performance, which increases risk should a threat subsequently arises, but limiting feeding behaviour may be maladaptive if food intake is unnecessarily reduced in the prediction of threats that do not arise. The efficacy of the trade-off between continued and interrupted feeding therefore relies on information about the future risk, which is imperfect. Here, we find that black carp (Mylopharyngodon piceus) can balance this trade-off using an a posteriori strategy; by eating to satiation but regurgitating already ingested food when a threat arises. While degrees of satiation (DS) equal to or greater than 60% reduce elements of escape performance (turning angle, angular velocity, distance moved, linear velocity), at 40% DS or lower, performance in these tasks approaches levels comparable to that at 0% satiation. After experiencing a chasing event, we find that fish are able to regurgitate already ingested food, thereby changing the amount of food in their gastrointestinal tract to consistent levels that maintain high escape performance. Remarkably, regurgitation results in degrees of satiation between 40 and 60% DS, regardless of whether they had previously fed to 40, 60 or 100% DS. Using this response, fish are able to maximize food intake, but regurgitate extra food to maintain escape performance when they encounter a threat. This novel strategy may be effective for continual grazers and species with imperfect information about the level of threat in their environment.     

Autophagic Protein Beclin 1 Serves as an Independent Positive Prognostic Biomarker for Non-Small Cell Lung Cancer

Beclin 1, a key regulator of autophagy, has been found to be aberrantly expressed in a variety of human malignancies. Herein, we employed immunohistochemistry (IHC) to detect the protein expression of Beclin 1 in non-small cell lung cancer (NSCLC) and paired normal adjacent lung tissues, and analyzed its clinicopathological/prognostic significance in NSCLC. Receiver operating characteristic (ROC) curve analysis was utilized to determine a cutoff point (>2 VS. ≤2) for Beclin 1 expression in a training set (n = 105). For validation, the ROC-derived cutoff value was subjected to analysis of the association of Beclin 1 with patients’ clinical characteristics and outcome in a testing set (n = 111) and the overall patient cohort (n = 216). Our data showed that Beclin 1 was significantly lower in NSCLC tissues compared with the adjacent normal tissues, negatively associating with tumor recurrence rate (65.8% VS 32.3%; p < 0.001). In the testing set and the overall patient cohort, low expression of Beclin 1 showed significantly inferior overall survival (OS) (p < 0.001) and progression-free survival (PFS) (p < 0.001) compared to high expression of Beclin 1. In the testing set and the overall patient cohort, the median duration of OS for patients with high and low expression of Beclin 1 was 108 VS. 24.5 months (p < 0.001) and 108 VS. 28 months (p < 0.001), respectively. Furthermore, low expression of Beclin 1 was also a poor prognostic factor within each stage of NSCLC patients. Multivariate analysis identified that Beclin 1 was an independent prognostic factor for NSCLC. Our findings in the present study provided evidence that Beclin 1 may thus emerge as an independent prognostic biomarker in this tumor entity in the future.     

Proteomic analysis of mouse liver plasma membrane: use of differential extraction to enrich hydrophobic membrane proteins

To comprehensively identify proteins of liver plasma membrane (PM), we isolated PMs from mouse liver by sucrose density gradient centrifugation. An optimized extraction method for whole PM proteins and several methods of differential extraction expected to enrich hydrophobic membrane proteins were tested. The extracted PM proteins were separated by 2-DE, and were identified by MALDI-TOF-MS, and ESI-quadrupole-TOF MS. As the complementary method, 1-DE-MS/MS was also used to identify PM proteins. The optimized lysis buffer containing urea, thiourea, CHAPS and NP-40 was able to extract more PM proteins, and treatment of PM samples with chloroform/methanol and sodium carbonate led to enrichment of more hydrophobic PM proteins. From the mouse liver PM fraction, 175 non-redundant gene products were identified, of which 88 (about 50%) were integral membrane proteins with one to seven transmembrane domains. The remaining products were probably membrane-associated and cytosolic proteins. The function distribution of all the identified liver PM proteins was analyzed; 40% represented enzymes, 12% receptors and 9% proteins with unknown function.     

Influence of Eight Unclassified Missense Variants of the MLH1 Gene on Lynch Syndrome Susceptibility

Missense mutations in MLH1 have frequently been detected in patients with Lynch syndrome, but their genetic significance has not been extensively assessed. In this study, we attempt to evaluate the etiological role of eight MLH1 missense variants. The variants were analyzed for their ability to affect MLH1 protein interaction with its partner PMS2 in vivo employing a yeast two-hybrid system. In addition, a SIFT (sorting intolerant from tolerant) algorithm was adopted to predict the effects of amino acid substitutions. Finally, scanning of mutations in a normal Chinese population and assay of the clinical characteristics have all been taken into account. Our results demonstrated that the MLH1 variants D485E and L653R cause functional alterations of the human MutLα complex significantly. The R265C, D304V, A586P, and R755S variants affect partial interaction. The remaining two variants, N38D and L559R, could be nonfunctional polymorphisms or might affect the mismatch repair system through other mechanisms.     

Effects of emodin and vitamin C on growth performance, biochemical parameters and two HSP70s mRNA expression of Wuchang bream (Megalobrama amblycephala Yih) under high temperature stress

In order to study the effects of dietary emodin, high-dose vitamin C (Vc) and their combination on growth of Wuchang bream (Megalobrama amblycephala Y.) and its resistance to high temperature stress, 1200 healthy Wuchang bream with initial body weight of 133.44 ± 2.11 g were randomly divided into four groups: a control group fed with basal diet (containing 50.3 mg/kg Vc) and three treated groups fed with basal diets supplemented with 60 mg/kg emodin, 700 mg/kg Vc, and the combination of 60 mg/kg emodin + 700 mg/kg Vc, respectively. After feeding for 60 days, the growth performance of Wuchang bream was measured. Then 25 fish per tank were exposed to heat stress of 34 °C. The biochemical parameters of blood and liver, and expression levels of liver two HSP70s mRNA before and after heat stress were determined and the cumulative mortality of each group under heat stress was counted. The results showed that before stress, compared with the control, the weight gain (WG) and specific growth rate (SGR), serum total protein (TP), lysozyme (LSZ), and alkaline phosphatase (ALP) levels, liver superoxide dismutase (SOD) activity and expression level of HSP70 mRNA significantly increased in emodin and Vc groups while feed conversion rate (FCR), serum cortisol (COR), triglyceride (TG) and liver malondialdehyde (MDA) contents decreased (P < 0.05); liver catalase (CAT) activity also significantly increased in emodin group (P < 0.05). Although serum TP, LSZ, and liver HSP70 mRNA levels significantly increased and liver MDA level decreased in combination group (P < 0.05), no synergism was observed. After heat stress, compared with the control, the serum TP, LSZ, ALP levels, liver SOD, CAT activities, and expression levels of HSC70 and HSP70 mRNAs increased in emodin and Vc groups in varying degrees and serum COR, glucose, glutamic-pyruvic transaminase (GPT), glutamic-oxaloacetic transaminase (GOT), TG and liver MDA levels decreased to some extent. Although these parameters had similar changing trend as above ones in combination group, it did not show any synergism either. Statistics showed that under heat stress, the cumulative mortalities of emodin and Vc groups, except at 6 h in emodin group, were significantly lower than that of the control (P < 0.05) while the difference between the combination and control groups was not significant (P > 0.05). Thus, the basal diet supplemented with 60 mg/kg emodin or 700 mg/kg Vc could promote the growth of Wuchang bream, reduce FCR, increase non-specific immunity of fish, antioxidant capacity, and two HSP70s mRNA expression levels, and enhance resistance to heat stress in fish. However, the combination of emodin and high-dose Vc showed no better effect.     

Large scale of identification of differentially expressed genes in the regenerating rat liver after SISPH

After partial hepatectomy (PH), the remnant paren-chyma can completely recover lost liver mass and function in about one week[1,2]. Although adult hepa-tocytes are normally quiescent, they are readily primed to pass from G0 to G1 phase within 2―6 h after PH. The first peak of DNA synthesis appears 24 h after PH, while cell division peaks at 36 h. The liver cells then enter a second cell cycle, and redifferentiation and reconstruction of structure and function[3―6] take place. A great nu…