MiR-130a regulating the biological function of colon cancer by targeting inhibition of PTEN.

OBJECTIVE: To investigate the expression of miR-130a in human colon cancer patients and its specific mechanism of regulating the biological function of colon cancer cells. PATIENTS AND METHODS: Cancer tissues, paracancerous tissues, and serum samples of 40 colon cancer patients who underwent surgery in The Second Affiliated Hospital of Qiqihar Medical University from May 2018 to March 2019 were collected, and 40 healthy volunteers who received physical examination in The Second Affiliated Hospital of Qiqihar Medical University were collected. Real Time-quantitative Polymerase Chain Reaction (qRT-PCR) was used to detect the expression of miR-130a. Human colon cancer cell was divided into miR-130a mimic group, miR-130a inhibitor group, mimic NC (negative control), and inhibitor NC group. QRT-PCR was used to detect the expression of miR-130a, and MTT assay, colony formation assay, cell scratch assay, transwell assay were performed to detect cell viability, proliferation, migration, and invasion ability. RESULTS: Compared with adjacent tissues, the expression of miR-130a was significantly increased in colon cancer tissues (p=0.0125); the expression of miR-130a in transfected miR-130a mimic group was higher than that in NC group, but the expression in transfected miR-130a inhibitor group was significantly lower than that in NC group; overexpression of miR-130a significantly increased cell viability, proliferation, migration, and invasion of colon cancer cells, while knockdown of miR-130a significantly inhibited colon cancer cell biological activity; target prediction, qRT-PCR, and Western blot assays showed that miR-130a participated in the development and progression of colon cancer by targeting inhibition of PTEN expression. CONCLUSIONS: The expression of miR-130a in serum and cancer tissues of colon cancer patients is significantly increased, and it can regulate the biological function of colon cancer cells by inhibiting the expression of target gene PTEN. Knockdown of miR-130a may be used as a new clinical treatment for colon cancer.

Dexmedetomidine protects against ischemia/reperfusion injury in rat kidney.

OBJECTIVES: Ischemia/reperfusion (I/R) injury in the kidney during perioperative period remains the leading cause of acute renal failure. The purpose of this experimental study was to determine the role of dexmedetomidine (Dex) on renal I/R injury in rats. MATERIALS AND METHODS: Male Wistar rats, subjected to renal ischemia for 45 min, were either untreated or treated with dexmedetomidine 30 min prior to renal ischemia. A sham-operated group served as the control. Renal function [serum creatinine, blood urea nitrogen, serum Cystatin C and neutrophil gelatinase-associated lipocalin (NGAL)], histology, apoptosis and expression of the phosphorylations of Janus kinase 2 (JAK2) and signal transducer and activator of transcription 3 (STAT3) were assessed. RESULTS: The animals treated with dexmedetomidine improved renal functional recovery, especially reducing the level of serum Cystatin C and NGAL at early time after ischemia, attenuated histological lesions, reduced tubular epithelial apoptosis and inhibited the phosphorylation of JAK2 and its downstream molecule STAT3, contributing to ameliorating renal I/R injury. CONCLUSIONS: Our data suggest that anti-apoptosis effect contributes to the renoprotection of dexmedetomidine, via inhibiting JAK2/STAT3 signaling pathway partially.

Association of a missense nucleotide polymorphism in the MT-ND2 gene with mitochondrial reactive oxygen species production in the Tibet chicken embryo incubated in normoxia or simulated hypoxia.

NADH dehydrogenase (complex I) catalyzes the transfer of electrons from NADH to ubiquinone with pumping protons across the mitochondrial inner membrane and produces reactive oxygen species as a major source in mitochondria. A missense mutation in the mitochondrially encoded NADH dehydrogenase 2 (MT-ND2) gene, which could produce a change in the protein's secondary structure, has been found in the Tibet chicken breed. In this study, breeding eggs of the Tibet chicken breed with the two genotypes were divided into two groups. One group was incubated in normoxia (20.9% oxygen concentration) and the other in simulated hypoxia (14.5% oxygen concentration). On the 16th day of incubation, complex I activity and mitochondrial reactive oxygen species production in the Tibet chicken embryonic liver with different genotypes in each group were measured. Results showed that: (1) hypoxia reduced complex I activity standardized and mitochondrial reactive oxygen species production significantly compared with normoxia and (2) the missense mutation in the MT-ND2 gene was significantly associated with the production of reactive oxygen species in mitochondria while not associated with the standardized or unstandardized activity of complex I.

Comparison of effects of hypoxia on glutathione and activities of related enzymes in livers of Tibet chicken and Silky chicken.

The Tibet chicken originates from the Qinghai-Tibet Plateau and has adapted well to hypoxia, whereas the Silky chicken is a lowland chicken breed from an area with an altitude of 750 m. The objective of the present study was to investigate whether differences exist in glutathione and related metabolism between the Tibet chicken and the Silky chicken when birds were housed in a normoxic or hypoxic chamber for 20 h. Activities of glutathione peroxidase, glutathione S-transferase, and glutathione reductase and levels of glutathione were determined spectrophotometrically. Under normoxia conditions and moderate hypoxia (14% oxygen concentration) conditions, no differences were found in levels of total glutathione, reduced glutathione (GSH), disulfide-oxidized glutathione (GSSG), the GSH:GSSG ratio, and activities of glutathione peroxidase and glutathione S-transferase between the Tibet chicken and the Silky chicken. Under extreme hypoxia conditions (14% oxygen concentration for 14 h and then 10.5% oxygen concentration for 6 h), values for the GSH content, the GSH:GSSG ratio, and the activity of glutathione reductase in the liver of the Tibet chicken were higher than those of the Silky chicken. The results indicate that the Tibet chicken responded better than the Silky chicken to oxidative stress in extreme hypoxia through glutathione enzymes of detoxification. This work provides reference for future studies on the association of glutathione metabolism with the adaptation to hypoxia.

Localisation of the genomic sequence interval for the blue eggshell gene using an F2 resource population of Dongxiang chickens.

1. In order to identify the molecular interval containing the blue shell gene (O locus), linkage analysis was conducted with three microsatellite markers, (TTA)(n), (TG)(n) and (tg)(n), and a SNP in intron 1 of SLCO1C1 (solute carrier organic anion transporter family, member 1C1; A locus) to map the O locus in an F2 resource population of Dongxiang chickens. 2. Linkage analysis based on 98 F2 hens resulted in estimation of the best map order of the O locus with other linked markers as: (TTA)(n)-(TG)(n)-A-O-(tg)(n). 3. Based on these results, we inferred that the O locus was located between the A and (tg)(n) loci, that is, Chr1:67,296,991-69,140,571, which is the first genomic sequence interval to be established for the blue eggshell gene.

Highly efficient dissociation of oxygen from hemoglobin in Tibetan chicken embryos compared with lowland chicken embryos incubated in hypoxia.

Oxygen is one of the critical determinants for normal embryonic and fetal development. In avian embryos, lack of oxygen will lead to high fetal mortality, heteroplasia, and cardiovascular dysfunction. Tibetan chicken is a breed native to Tibet that could survive and keep higher hatchability regardless of negative effects of hypoxia. Generally, adaptive animals in high altitudes are characterized by higher hemoglobin concentrations and oxygen affinity. In the present study, the capacity of oxygen supply in late chick embryo (including d 17, 19, and 21) was compared between Tibetan chicken and a lowland breed, Dwarf White chicken, by determining the hemoglobin concentrations and oxygen equilibrium curves in both hypoxic (13% O(2)) and normoxic (21% O(2)) conditions. The results showed that a higher level of hemoglobin concentration was induced by hypoxia in Tibetan chicken embryos, and the hemoglobin could perform with better cooperativity and deliver oxygen to tissues more easily. Further investigation revealed that the carbonic anhydrase II mRNA in red blood cells of Tibetan chicken was increasingly induced to a higher level in hypoxia than that of the lowland breed. These results suggested that the stronger capacity of oxygen dissociation was an important characteristic of Tibetan chicken embryo to survive in hypoxia and the upregulating mode of carbonic anhydrase II mRNA might assist this dissociation. Therefore, for avian at high altitudes, the efficient dissociation of oxygen might reveal another aspect associated with the hypoxia adaptability.

A comparison of mitochondrial respiratory function of Tibet chicken and Silky chicken embryonic brain.

The Tibet chicken lives in high altitude and has adapted itself well to hypoxia. The Silky chicken is a lowland chicken from Jiangxi province of China. The objective of the present study was to investigate whether there were any differences in brain mitochondrial respiratory function between Tibet chicken and Silky chicken embryos incubated in a normoxic (21% oxygen concentration) or simulated hypoxic (13% O(2)) hatchibator. Brain mitochondria of chicken embryos were prepared by differential centrifugation on d 16 of incubation. The respiratory control ratio (RCR) and the adenosine 5'-diphosphate: oxygen ratio (ADP/O) were determined polarographically. The complex I activity was measured with an ultraviolet spectrophotometer by following the oxidation of the reduced state of beta-nicotinamide adenine dinucleotide. Under the normoxic incubation condition, there were no significant differences in the RCR, the ADP/O, and the activity of complex I between embryonic brain mitochondria of the 2 breeds. Under the hypoxic incubation condition, the ADP/O in brain mitochondria of embryos from the 2 breeds were identical. Also under hypoxic conditions the RCR in brain mitochondria of Tibet chicken embryos was higher (P < 0.05) than in Silky chicken embryos when brain mitochondria were provided with glutamate-malate, but no significant difference was found in the RCR with succinate as an energy substrate. The complex I activity of Silky chicken embryos was higher than that of Tibet chicken embryos when they were incubated in the hypoxic hatchibator (P < 0.01). In conclusion, the results show that under simulated hypoxic incubation conditions electron transport in brain mitochondria of Tibet chicken embryos was more tightly coupled than that of lowland chicken (Silky chicken) embryos with glutamate-malate as energy substrate, which was associated with the difference in the activity of complex I between embryonic brains of the 2 breeds. This work will provide reference for future studies on the association of mitochondrial respiratory function with the adaptation to hypoxia.

Association of MT-ND5 gene variation with mitochondrial respiratory control ratio and NADH dehydrogenase activity in Tibet chicken embryos.

NADH dehydrogenase (complex I) couples the oxidation of NADH for the reduction of ubiquinone with the generation of a proton gradient that can be used for the synthesis of ATP. We have found a missense mutation in the MT-ND5 subunit of NADH dehydrogenase in the Tibet chicken breed. In the present study, the mitochondrial respiratory control ratio (RCR) and NADH dehydrogenase activity in Tibet chicken embryonic brain with different genotypes were measured. Significant differences between animals carrying mitochondria with the EF493865.1:m.1627A vs. EF493865.1:m.1627C alleles were observed for RCR and enzyme activity.

Expression pattern of HIF1α mRNA in brain, heart and liver tissues of Tibet chicken embryos in hypoxia revealed with quantitative real-time PCR.

The problem of hypoxia adaptation in high altitudes is an unsolved brainteaser in the field of the life sciences. As one of the best chicken breeds with adaptability to highland environment, the Tibet chicken, is genetically different from lowland chicken breeds. It is well known that hypoxia has significant impact on growth by inducing the expression of the alpha subunit of the heterodimeric transcription factor, hypoxia-inducible factor 1 (HIF1α). In the present study, HIF1α expression in brain, heart and liver tissues of the Tibet and Dwarf Recessive White chicken embryos were investigated at the different development stages of days 10, 17 and 20 by real-time PCR, and the expression pattern of HIF1α in chicken embryos of the two chicken breeds incubated under conditions of hypoxia (13% O2) and normoxia (21% O2) was studied. The incubation mortality of the Tibet chicken was lower than the Dwarf Recessive White chicken during the whole incubation in hypoxia, and the mRNA expression of HIF1α had presented the differences in three tissues. The results implied that the hypoxia adaptability of the Tibet chicken embryo was higher than the Dwarf Recessive White chicken, especially in the early stage (day 10) and at a later time (day 20) during the incubation period, but the mechanism of the oxygen transfer of embryos of mountain species is not completely understood, and hypoxia adaptability of the Tibetan chicken remains to be studied further.