[Research advances of metabolomics in early diagnosis of hepatocellular carcinoma].

Primary liver cancer is the second leading cause of death from malignant tumors in China, and hepatocellular carcinoma (HCC) is the main type. The disease stage at the time of HCC diagnosis largely determines the efficacy of subsequent treatment. Due to the HCC screening among high-risk population has not yet popularized, and the current diagnose method of early HCC is not satisfactory, the early HCC diagnosis rate is less than 30% in China. Metabolomics research emerging in recent years has promoted the research progress of HCC in many fields, such as elaborating the mechanism of occurrence and development, early prevention and diagnosis, exploring drug treatment targets. At the same time, a large number of serum metabolites with excellent sensitivity and specificity were discovered, which made up for the deficiency of traditional serological indicators and helped the early screening and early diagnosis of HCC. This review will summarize the studies on serum metabolomic markers of HCC in recent 5 years, explore the role of metabolomics in the early prediction and diagnosis of HCC and its application prospect.

Role of Hsa-miR-122-3p in steroid-induced necrosis of femoral head.

OBJECTIVE: To explore the clinical correlation between the hsa-miR-122-3p expression in bone marrow mesenchymal stem cells (BMSCs) and steroid-induced necrosis of femoral head (SONFH). PATIENTS AND METHODS: A total of 62 SONFH patients were selected as the experimental group, while another 72 patients with femoral neck fracture (FNF) were selected as the control group. The bone marrow was obtained from patients during operation and used to culture the BMSCs. The expression of hsa-miR-122-3p in BMSCs was detected via real-time quantitative polymerase chain reaction (qPCR) in both groups. The patients in experimental group were further divided into Ficat stage III group and stage IV group according to the Ficat stage, and the expression of hsa-miR-122-3p in BMSCs was also detected via qPCR in the two groups. RESULTS: The expression level of hsa-miR-122-3p in SONFH group was significantly lower than that in FNF group, and the difference was statistically significant (p<0.05). The expression level of hsa-miR-122-3p in Ficat stage IV group was significantly lower than that in stage III group (p<0.05). CONCLUSIONS: We demonstrated that the expression of hsa-miR-122-3p in BMSCs declined in SONFH group, indicating that hsa-miR-122-3p may be involved in the regulation of the pathological process of SONFH, and the expression level of hsa-miR-122-3p in BMSCs may be correlated with the progression of SONFH.

MiRNA-27a-3p promotes osteogenic differentiation of human mesenchymal stem cells through targeting ATF3.

OBJECTIVE: To elucidate whether miRNA-27a-3p can promote osteogenic differentiation of hMSCs by targeting ATF3, thus alleviating osteoporosis symptoms. PATIENTS AND METHODS: The serum levels of miRNA-27a-3p in osteoporosis patients (n=20) and normal controls (n=20) were detected by quantitative Real Time-Polymerase Chain Reaction (qRT-PCR). Human bone marrow mesenchymal stem cells (hMSCs) were subjected to osteogenic differentiation for 1, 3 and 7 days. Subsequently, mRNA levels of miRNA-27a-3p, ALP, and Bglap in hMSCs were determined by qRT-PCR. The regulatory effects of miRNA-27a-3p levels and the mRNA levels of ALP, Bglap, and Runx2 were detected. After the overexpression or knockdown of miRNA-27a-3p, we evaluated the changes in the osteogenic differentiation by alizarin red staining and ALP staining. Through Dual-Luciferase Reporter Gene Assay, we verified the binding relationship between miRNA-27a-3p and ATF3. Rescue experiments were finally conducted to prove whether miRNA-27a-3p regulated the osteogenic differentiation by targeting ATF3. RESULTS: The serum level of miRNA-27a-3p remained lower in osteoporosis patients relative to controls. With the prolongation of osteogenic differentiation, the mRNA levels of miRNA-27a-3p, ALP, and Bglap gradually increased. The overexpression of miRNA-27a-3p upregulated mRNA and the protein levels of osteogenesis-related genes, increased ALP activity, and enhanced mineralization capacity. The knockdown of miRNA-27a-3p obtained the opposite trends. MiRNA-27a-3p could target ATF3, and the overexpression of ATF3 reversed the promotive effects of miRNA-27a-3p on osteogenic differentiation. CONCLUSIONS: MiRNA-27a-3p promotes the differentiation of hMSCs into osteoblasts by targeting ATF3, thus alleviating osteoporosis symptoms.

Oridonin Induces Apoptosis in Human Nasopharyngeal Carcinoma Cells Involving ROS Generation.

Oridonin, an ent-kaurene diterpenoid isolated from the traditional Chinese herb Rabdosia rubescens, has been reported to be a potent cytotoxic agent against a wide array of cancer cells. However, its effect on human nasopharyngeal carcinoma (NPC) cells has not been well investigated. The present study aimed to explore the anti-tumour effect of oridonin in NPC cells and its underlying mechanisms. Cell viability was examined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide assay and colony formation assay. Apoptosis, mitochondrial membrane potential (MMP), reactive oxygen species (ROS), and expression of apoptosis-related proteins were analysed by flow cytometry with propidium iodide staining, JC-1 staining, DCFH-DA staining, and Western blot analysis, respectively. The results showed that oridonin concentration-dependently inhibited the cell viability, decreased the colony formation, and enhanced the apoptotic rate in NPC cells. Further, oridonin-induced apoptosis was mediated by the mitochondrial pathway in NPC cells, which was confirmed by the loss of MMP, downregulation of anti-apoptotic Bcl-2 family protein Mcl-1 and Bcl-2, upregulation of pro-apoptotic Bcl-2 family member Bax, and activation of caspase-3 and PARP. Notably, the augmented ROS generation played an essential role in oridonin-induced apoptosis in NPC cells, as the apoptosis-inducing effect was attenuated by ROS scavenger N-acetyl-L-cysteine. These results indicate that oridonin triggers apoptosis through the ROSmediated mitochondrial pathway in NPC cells. This study supports oridonin to be an interesting candidate drug for the treatment of human NPC.

Natriorexigenic effect of DAMGO is decreased by blocking AT1 receptors in the central nucleus of the amygdala.

µ-Opioid receptor (µ-OR) activation with agonist [D-Ala², N-Me-Phe4, Gly5-ol]-enkephalin (DAMGO) in the central nucleus of the amygdala (CeA) induces sodium (0.3M NaCl) intake in rats. The purpose of this study was to examine the effects of pre-injections of losartan (AT1 angiotensin receptor antagonist) into the CeA on 0.3 M NaCl and water intake induced by DAMGO injected bilaterally in the same area in rats submitted to water deprivation-partial rehydration (WD-PR) and in rats treated with the diuretic furosemide (FURO) combined with a low dose of the angiotensin-converting enzyme inhibitor captopril (CAP) injected subcutaneously (FURO/CAP). Male Sprague-Dawley rats with stainless steel cannulas implanted bilaterally into the CeA were used. In WD-PR rats, bilateral injections of DAMGO (2 nmol in 0.5 µL) into the CeA induced 0.3 M NaCl and water intake, and pre-treatment with losartan (108 nmol in 0.5 µL) injected into the CeA reduced 0.3 M NaCl and water intake induced by DAMGO. In FURO/CAP rats, pre-treatment with losartan (108 nmol in 0.5 µL) injected into the CeA attenuated the increase in 0.3M NaCl and water intake induced by DAMGO (2 nmol in 0.5 µL) injected into the same site. The results suggest that the natriorexigenic effect of DAMGO injected into the CeA is facilitated by endogenous angiotensin II acting on AT1 receptors in the CeA, which drives rats to ingest large amounts of hypertonic NaCl.

Reentrant behaviour in Y-doped Ho(0.75)Y(0.25)Ni(2)B(2)C single crystal.

The transport and superconducting properties of Ho(0.75)Y(0.25)Ni(2)B(2)C single crystals were investigated to study the competing effects between superconductivity and magnetism. The superconducting transition temperature T(c) is 7.6 K, determined from the resistivity transition; meanwhile, the commensurate antiferromagnetic (AFM) transition occurs at T(N) of 3.9 K, which is lower than that of pure HoNi(2)B(2)C (T(N)≈5 K). Ho(0.75)Y(0.25)Ni(2)B(2)C reentered into the normal state at T(m) (T(N)

Molecular modeling of mu opioid receptor and receptor-ligand interaction.

AIM: To construct the 3D structural model of mu opioid receptor (mu OR) and study the interaction between mu OR and fentanyl derivatives. METHODS: The 3D structure of mu OR was modeled using the bacteriorhodopsin (bRh) as a template, in which the alignments of transmembrane (TM) of bRh and mu OR were achieved by scoring the alignment between the amino acid sequence of mu OR and the structure of bRh. The fentanyl derivatives were docked into the 7 helices of mu OR and the binding energies were calculated. RESULTS: (1) The receptor-ligand interaction models were obtained for fentanyl derivatives. (2) In these models, the fundamental binding sites were possibly Asp147 and His297. The negatively charged oxygen of Asp147 and the positively charged ammonium group of ligand formed the potent electrostatic and hydrogen-binding interactions. Whereas the interactions between the positively charged nitrogen of His297 and the carbonyl oxygen of ligand were weak. In addition, there were some pi-pi interactions between the receptor and the ligand. (3) The binding energies of the receptor-ligand complexes had a good correlation with the analgesic activities (-lg ED50) of the fentanyl derivatives. CONCLUSION: This model is helpful for understanding the receptor-ligand interaction and for designing novel mu OR selective ligands.

Molecular modeling of voltage-gated potassium channel pore.

AIM: To build a structure model for the pore of voltage-gated Shaker potassium channel and examine its validity. METHODS: (1) Structural restraints were derived from experimental and theoretical studies; (2) An initial structural motif satisfying the derived restraints was first constructed, and further refined by restrained molecular mechanics; (3) The quality of the model was judged by the criterion that whether it could clarify molecular mechanisms of channel functions and explain the known experimental facts. RESULTS: (1) A computer pore structure was proposed, in which the residues within signature sequence (corresponding to Shaker 439-446) dipped into the membrane and formed the narrow part of the pore in a non-periodic conformation, while the other residues in the P region constituted the outer mouth of the pore; (2) The ion selectivity was achieved through cation-pi orbital interaction mechanism at position 445 and oxygen cage mechanism at position 447; (3) Different binding modes led to different affinity of CTX and AgTx2 to channel; and (4) The inside of pore was dominated by negative electrostatic potential. CONCLUSION: The model proposed was consistent with the derived restraints from the experimental results.

Interaction models of 3-methylfentanyl derivatives with mu opioid receptors.

AIM: To study the interaction model of 3-methylfentanyl derivatives with mu opioid receptor. METHODS: After a systematic conformational search, a three-dimensional quantitative structure-activity relationship study was carried out with comparative molecular field analysis (CoMFA). RESULTS: 1) The 6 CoMFA models had good predictive values and each model corresponded to the minimum-energy conformations of 13 compounds studied; 2) The important geometric parameters of mu pharmacophore d1 (A), d2 (A), d3 (A), d4 (A), d5 (A), and d6 (A) were 5.2, 5.4, 4.9, 10.6, 10.2, and 5.8 in Model A; 5.2, 6.5, 3.6, 10.6, 11.6, and 5.8 in Model B; 5.2, 4.6, 4.9, 11.6, 9.2, and 6.5 in Model C; 5.2, 5.4, 4.9, 10.5, 10.3, and 5.8 in Model D; 3.6, 5.4, 4.9, 5.7, 7.5, and 5.7 in Model E; 5.2, 4.7, 4.9, 11.2, 9.5, and 6.4 in Model F, respectively. CONCLUSIONS: The several bioactive conformations of fentanyl analogs possibly existed and did not need to be the absolute minimum-energy conformation, each of which was involved in the interaction with mu opioid receptor.

Structure-activity relationship of channel binding affinity of quaternary ammonium ions.

AIM: To explore the structure-activity relationship of quaternary ammonium (QA) ions at the external binding site of K+ channel. METHODS: InsightII and MOPAC 6.0 molecular modeling package were used to calculate the free energy of hydration (delta Ghydration), the energy of the highest occupied orbital (EHOMO), and the energy of the lowest unoccupied orbital (ELUMO) for each QA ion, respectively. The partial least square method was used to analyze the relationship between the binding free energy and these descriptive parameters. RESULTS: Generally, the higher the ELUMO of a QA ion was, the weaker its solvation was and accordingly the stronger binding affinity. For a QA ion larger than tetraethylammonium (TEA), its large size was unfavorable to its channel binding affinity. CONCLUSION: The binding affinity of all QA ions correlated well with delta Ghydration and ELUMO.

Rearrangement of the retinoic acid receptor gene in acute promyelocytic leukemia.

The retinoic acid receptor-alpha (RAR-alpha) gene was previously localized to chromosome 17q21, a region close to the t(15;17) (q22;q21) abnormality in acute promyelocytic leukemia (APL). We used the RAR-alpha gene as a probe and found that eight of nine APL patient samples with t(15;17) (q22;q21) showed rearranged bands. A tenth APL patient was diploid and demonstrated no rearrangement. One patient who had rearrangement as an acute leukemia did not have rearrangement in remission. The results obtained from intron/exon mapping of the RAR-alpha gene demonstrated that breakpoints of seven of the eight patients occurred within intron 1. Northern blot analysis of leukemic samples indicated the expression of two RAR-alpha mRNA of 2.7 and 3.7 kb. However, two additional mRNA of 4.1 and 3.2 kb were found in an APL patient. We conclude that the RAR-alpha gene is directly involved in the t(15;17) translocation in APL and may transcribe aberrant messages.

Down regulation of myeloperoxidase gene associated with specific nuclease hypersensitive sites during TPA induced differentiation of HL-60.

The level of myeloperoxidase (MPO) mRNA is reduced significantly after HL-60 induced differentiation with the tumor promoter 12-O-tetradecanoylphorbol-13-acetate (TPA). We examined the chromatin structural changes of the MPO gene during TPA induction. Before TPA induction about nine DNase I hypersensitive sites (HS) were found on the 5' upstream and at various intron regions of the MPO gene. A new HS was found on intron 8 within 4 h of induction; its appearance preceded down regulation of the MPO gene. At the same time DNase I HS found in 0.3 and 1-1.5 kb upstream of the MPO CAP site, were significantly reduced or disappeared after TPA induction. These chromatin structural changes could be closely linked to the mechanism which regulates the MPO gene expression.

[Origin of the auditory middle latency response Pa in guinea pig].

The cortex of guinea pig was divided into five regions and respective ablation of the different regions combined with local infiltration of kainic acid on the cortex was made to investigate the relationship between the different part of the cortex and MLR. The results of ablation showed that the main component of the MLR, wave Pa, still appeared unless the primary auditory cortex contralateral to the stimulated ear was removed. With local application of kainic acid it was further suggested that the Pa mainly originates from the neurons in the primary auditory cortex and that subcortical auditory structures and their projected fibers do not contribute to the Pa.