[Lactate promotes HMGB1 phosphorylation and release via Akt signaling pathway in gastric cancer cells HGC-27].

Objective: To investigate the molecular mechanism of how lactate induces high mobility group box 1 (HMGB1) release. Methods: Gastric cancer HGC-27 cells were divided into the control group and the lactate group (The cells were treated with lactate for 6 h). The level of HMGB1 in the cell culture medium was detected by enzyme-linked immunosorbent assay (ELISA), the localization of HMGB1 was detected using laser confocal microscopy, and the nuclear translocation of HMGB1 was detected using the nucleoplasmic separation assay. The phosphorylation and acetylation levels of HMGB1 were determined by co-immunoprecipitation, and Western blot was used to measure the phosphorylation of Akt and protein kinase C (PKC). HGC-27 cells were first treated with lactate and LY294002, the inhibitor of Akt, and then the phosphorylation of HMGB1 and Akt was analyzed by co-immunoprecipitation and Western blot, respectively. The localization of HMGB1 in cells was detected by laser confocal microscopy. EdU and Transwell assays were used to detect the proliferation and migration abilities of HGC-27 cells, respectively. HGC-27 cells were then injected into the BALB/C null mice for subcutaneous tumor implantation. Mice in the lactate group were intraperitoneally injected with lactate (0.2 g/kg/2 d), while those in the control group were intraperitoneally injected with an equal amount of PBS for 20 consecutive days. ELISA was used to detect the HMGB1 levels in the blood samples taken from the medial canthus vein of the mice, while co-immunoprecipitation and Western blot were used to detect the phosphorylation of HMGB1 and Akt in tumor tissue proteins, respectively. Results: The release levels of HMGB1 in the lactate group were (2 995.00±660.91) pg/ml and (696.33±22.03) pg/ml, after lactate treatment for 6 h and 12 h, respectively, both higher than those in the control group (485.00±105.83) pg/ml (P<0.001 and P=0.028, respectively). After lactate treatment for 6 h, the relative expression of HMGB1 protein in the cytoplasm of HGC-27 cells was 1.13±0.09, higher than that of the control group (0.83±0.07, P=0.001), while the relative expression of HMGB1 in the nucleus was 0.79±0.06, lower than that of the control group (1.07±0.06, P=0.007). The phosphorylation level of HMGB1 reached 1.41±0.09, which was higher than that of the control group (0.97±0.10, P=0.031). The phosphorylation level of Akt was 11.16±0.06, higher than that of the control group (0.91±0.022, P=0.002). The phosphorylation level and nuclear translocation of HMGB1 induced by lactate decreased obviously after Akt inhibition; the proliferation and migration abilities induced by lactate were also obviously inhibited after Akt inhibition. In vivo, the HMGB1 level in the peripheral blood was (1 280.70±389.66) pg/ml in the lactate group, which was obviously higher than that in the control group (595.11±44.75) pg/ml (P=0.008), and the phosphorylation levels of HMGB1 and Akt in tumor tissues in the lactate group were obviously enhanced compared with the control group. Conclusion: Lactate induces HMGB1 release through enhancing HMGB1 phosphorylation via the Akt signaling pathway.

[Research progress in anti-reflux reconstructions and mechanism after proximal gastrectomy].

The electrophysiological activity of the gastrointestinal tract and the mechanical anti-reflux structure of the gastroesophageal junction are the basis of the anti-reflux function of the stomach. Proximal gastrectomy destroys the mechanical structure and normal electrophysiological channels of the anti-reflux. Therefore, the residual gastric function is disordered. Moreover, gastroesophageal reflux is one of the most serious complications. The emergence of various types of anti-reflux surgery through the mechanism of reconstructing mechanical anti-reflux barrier and establishing buffer zone, and the preservation of, the pacing area and vagus nerve of the stomach, the continuity of the jejunal bowel, the original gastroenteric electrophysiological activity of the gastrointestinal tract, and the physiological function of the pyloric sphincter, are all important measures for gastric conservative operations. There are many types of reconstructive approaches after proximal gastrectomy. The design based on the anti-reflux mechanism and the functional reconstruction of mechanical barrier, and the protection of gastrointestinal electrophysiological activities are important considerations for the selected of reconstructive approaches after proximal gastrectomy. In clinical practice, we should consider the principle of individualization and the safety of radical resection of tumor to select a rational reconstructive approaches after proximal gastrectomy.

Development of novel polymorphic microsatellite markers for the silver fox (Vulpes vulpes).

The silver fox (Vulpes vulpes), a coat color variant of the red fox, is one of the most important fur-bearing animals. To date, development of microsatellite loci for the silver fox has been limited and mainly based on cross-amplification by using canine SSR primers. In this study, 28 polymorphic microsatellite markers were isolated and identified for silver fox through the construction and screening of an (AC)n-enriched library. The number of alleles per locus ranged from 2 to 8 based on 48 individuals tested. The expected and observed hetero- zygosity and polymorphism information content per locus ranged from 0.2544 to 0.859, 0.2083 to 0.7917, and 0.2181 to 0.821, respectively. The polymorphic markers presented in this study may be useful for future analysis of the genetic diversity and population structure of farmed silver fox and wild red fox.

Cloning and association analysis of KIT and EDNRB polymorphisms with dominant white coat color in the Chinese raccoon dog (Nyctereutes procyonoides procyonoides).

The Chinese raccoon dog (Nyctereutes procyonoides procyonoides) is one of the most important fur-bearing animal species. The dominant white individual, a coat color variant in farmed Chinese raccoon dog, shows a completely white phenotype over the entire body. The KIT and EDNRB genes have been reported to be associated with the dominant white coat color in some mammalian species. In the present study, the full-length coding sequences of KIT and EDNRB were amplified from a dominant white and a wild-type Chinese raccoon dog. Sequence analysis revealed that the coding region of KIT and EDNRB in Chinese raccoon dog was 2919 and 1332 base pairs in length (accession No. KM083121 and KM083122), respectively, and 2 single-nucleotide polymorphisms (SNPs; c.600C>T and c.967G>A) in KIT and 1 SNP (c.259A>C) in EDNRB was found only in the dominant white individual. An alternative splicing site at the boundary of 4 and 5 of the KIT gene was identified in both individuals. We further investigated the association between the 3 SNPs of KIT and EDNRB and dominant white coat color by genotyping 18 individuals. We found no association between these SNPs and dominant white coat color. Based on these results, we can exclude the coding regions of the KIT and EDNRB genes as determinants of the dominant white coat color in Chinese raccoon dog.