Binding between ROCK1 and DCTN2 triggers diabetes­associated centrosome amplification in colon cancer cells.

Type 2 diabetes increases the risk various types of cancer and is associated with a poor prognosis therein. There is also evidence that the disease is associated with cancer metastasis. Centrosome amplification can initiate tumorigenesis with metastasis in vivo and increase the invasiveness of cancer cells in vitro. Our previous study reported that type 2 diabetes promotes centrosome amplification via the upregulation and centrosomal translocation of Rho­associated protein kinase 1 (ROCK1), which suggests that centrosome amplification is a candidate biological link between type 2 diabetes and cancer development. In the present study, functional proteomics analysis was used to further investigate the molecular pathways underlying centrosome amplification by targeting ROCK1 binding partners. High glucose, insulin and palmitic acid were used to induce centrosome amplification, and immunofluorescent staining was employed to visualize centrosomal alterations. Combined with immunoprecipitation, mass spectrometry­based proteomics analysis was used to identify ROCK1 binding proteins, and protein complex disruption was achieved by siRNA­knockdown. In total, 1,148 ROCK1 binding proteins were identified, among which 106 proteins were exclusively associated with the treated samples, 193 were only associated with the control samples, and 849 were found in both the control and treated samples. Of the proteins with evidence of centrosomal localization, Dynactin subunit 2 (DCTN2) was confirmed to be localized to the centrosomes. Treating the cells with high glucose, insulin and palmitic acid increased the protein levels of ROCK1 and DCTN2, promoted their binding with each other, and triggered centrosome amplification. Disruption of the protein complex by knocking down ROCK1 or DCTN2 expression partially attenuated centrosome amplification, while simultaneous knockdown of both proteins completely inhibited centrosome amplification. These results suggested ROCK1­DCTN2 binding as a signal for the regulation of centrosome homeostasis, which is key for diabetes­associated centrosome amplification, and enriches our knowledge of centrosome biology. Therefore, the ROCK1­DCTN2 complex may serve as a target for inhibiting centrosome amplification both in research or future therapeutic development.

Valine acts as a nutritional signal in brain to activate TORC1 and attenuate postprandial ammonia-N excretion in Chinese perch (Siniperca chuatsi).

An emerging concept is that the hypothalamic nutrient sensor can regulate peripheral energy metabolism via a brain-liver circuit. Valine is an essential branched-chain amino acid (BCAA) that drives intracellular signaling cascades by the activation of target of rapamycin complex 1 (TORC1) which is critical to protein metabolism in mammals. However, in teleost fish, it remains scarce in this area especially about how the intraventricular (ICV) injection of valine can mediate the protein metabolism in peripheral organs. This study would tentatively explore the effects of ICV injection of valine on protein metabolism in peripheral organs through evaluating the postprandial ammonia-N excretion rate in Chinese perch. The control group was injected with 5-µL PBS, and the Val group was injected with 20-µg L valine dissolved into 5-µL PBS. The ammonia-N excretion rate of Val group was lower than control group at 4-, 12-, and 24-h postinjection, while the concertation of plasma glucose was increased sharply at 0.5-, 4-, 12-, and 24-h postinjection. We further checked both mRNA level and the enzyme activity of glutamate dehydrogenase (GDH) in the liver and adenosine monophosphate deaminase (AMPD) in muscle, and we found that they were obviously decreased in Val group at 4-, 12-, and 24-h postinjection. The phosphorylation level of ribosomal protein S6, a downstream target protein of TORC1, was markedly enhanced in the liver of Val group at 4-, 12-, and 24-h postinjection. Collectively, these results illustrated that ICV injection of valine can attenuate protein degradation in peripheral organs by depressing the GDH and AMPD enzyme activity; on the other hand, the injected valine can trigger the activation of TORC1 in the liver via a brain-liver circuit and then interdict proteolysis.

Social Learning of Acquiring Novel Feeding Habit in Mandarin Fish (Siniperca chuatsi).

Social learning plays important roles in gaining new foraging skills and food preferences. However, the potential role and molecular mechanism of social learning in acquiring new feeding habits is less clear in fish. In the present study, we examined the success rate of feeding habit domestication from live prey fish to dead prey fish, as well as the food intake of dead prey fish in mandarin fish with or without feeders of dead prey fish as demonstrators. Here, we found that mandarin fish can learn from each other how to solve novel foraging tasks, feeding on dead prey fish. In addition, the analysis of gene expressions and signaling pathways of learning through Western blotting and transcriptome sequencing shows that the expression of the c-fos, fra2, zif268, c/ebpd and sytIV genes were significantly increased, and the anorexigenic pomc and leptin a expressions were decreased in fish of the learning group. The phosphorylation levels of protein kinase A (PKA) and Ca2+/calmodulin-dependent protein kinase II (CaMKII) in the learning group were significantly higher than those of the control group, while the phosphorylation level of S6 ribosomal protein (S6) was lower. With the inhibitors of PKA and CaMKII signaling and the chromatin immunoprecipitation (ChIP) assay, we further found that the social learning of new feeding habits in mandarin fish could be attributed to the activation of the CaMKII signaling pathway and then the stimulation of the expression of the c-fos gene, which might be an important transcriptional factor to inhibit the expression of the anorexigenic gene pomc, resulting in the food intake of dead prey fish in mandarin fish. Altogether, our results support the hypothesis that social learning could facilitate the acquisition of novel feeding habits in fish, and it considerably increases the rate of subsequent individual food intake and domestication through the interaction between the learning gene c-fos and the appetite control gene pomc.

[Non small cell lung cancer gene expression profiles by cDNA microarrays].

OBJECTIVE: To study lung squamamouscarcinoma and lung adenocarcinoma gene expression profiles by cDNA microarrays, compare them with those of pulmonary inflammatory pseudoneoplasma, and screen the differential expression gene and the common expression gene in these types of lung cancer in order to further study early diagnosis and treatment of lung cancer. METHODS: cDNA microarray chips containing 4096 human target genes were used to identify gene expression profiles in lung squamous cell carcinoma, adenocarcinoma, and pulmonary inflammatory pseudoneoplasma. RESULTS: Among the target genes, 591 differentially expressed genes were identified in lung squamous cell carcinoma; among them, there were 476 genes unexpressed in pulmonary inflammatory pseudoneoplasma; 293 of 476 differentially expressed genes were up-regulated and the other 183 were down-regulated. There were 524 differentially expressed genes in adenocarcinoma; among them, 460 genes were not expressed in pulmonary inflammatory pseudoneoplasma; 214 of the 460 differentially expressed genes were up-regulated and 246 were down-regulated. However, there were a total of 113 genes differentially expressed the both lung squamous cell carcinoma and adenocarcinoma. CONCLUSION: There were distinct gene expression profiles among lung squamous cell carcinoma and adenocarcinoma. All those gene expression profiles and genes screened out provide important clues for further investigation of carcinogenesis, invasion and metastasis of non small cell lung cancer and its molecular characteristics.

Plasma L-ENK, AVP, ANP and serum gastrin in patients with syndrome of Liver-Qi-stagnation.

AIM:To investigate the pathophysiologic basis of syndrome of Liver-Qi stagnation and parameters for clinical differentiation.METHODS:Plasma L-ENK, AVP, ANP and serum gastrin were determined by RIA in 84 patients with neurasthenia, mastodynia,chronic gastritis, and chronic cholecystitis presenting the same syndrome of Liver-Qi stagnation in traditional Chinese medicine (TCM). Healthy subjects served as controls in comparison with patients having the same syndrome but with different diseases.RESULTS:Among the patients with Liver-Qi stagnation, the plasma L-ENK, ANP and gastrin levels were 38.83ng/L ± 6.32ng/L, 104.11ng/L ± 29.01ng/L and 32.20ng/L ± 6.68ng/L, being significantly lower than those in the healthy controls (P < 0.01, t = 3.34, 6.17, 4.48). The plasma AVP of the patient group (52.82ng/L ± 19.09ng/L) was significantly higher than that of the healthy controls (P <0.01, t = 5.79 =. The above changes in patients having the same symptom complex but different diseases entities showed no significant differences, P >0.05.CONCLUSION:The syndrome of Liver-Qi stagnation is closely related to the emotional modulatory abnormality of the brain, with decrease of plasma L-ENK, ANP and gastrin, and increase of plasma AVP as the important pathophysiologic basis.