[The progress of studying the mechanisms of immune cells in the regulation of non-alcoholic fatty liver diseases]

Non-alcoholic fatty liver diseases (NAFLD) are liver diseases which are strongly associated with obesity. The incidence of NAFLD has been gradually increased in recent years. According to different pathology of the liver, NAFLD include three disease states: simple fatty liver, hepatitis (nonalcoholic steatohepatitis, NASH) and fatty liver cirrhosis. The accumulations of fat around the internal organs, which secrete a wide range of adipokines, such as interleukin-6, contribute the development and progress of NAFLD in obesity. In addition, the liver has been recognized as an immune organ containing several immune cells, for instance, inherited macrophages in the live (kupffer cells), nature killer cells, T lymphocytes, T regulatory cells (Tregs), myeloid-derived suppressor cells (MDSCs), and dendritic cells. These immune cells secret a number of cytokines, such as tumor necrosis factor (TNF-α) and monocyte chemoattractant protein (MCP-1), play important roles in the development of NAFLD. Moreover, a high level of fatty acids in the liver microenvironment, leads to suppress CD4(+)T cells and the loss of CD4(+)T cells in the microenvironment of the liver may be one of key factors which is associated with the progress of NAFLD to cirrhosis and liver cancer. This article aims to review the recent studies in the mechanisms of these immune cells involving in the progress of NAFLD, and to explore the novel strategies targeting these immune cells to control the prevalence of NAFLD and reduce liver fibrosis.

The effect of glucose-dependent insulinotropic polypeptide (GIP) variants on visceral fat accumulation in Han Chinese populations

Objectives:

We aim to validate the effects of glucose-dependent insulinotropic polypeptide (GIP) on fat distribution and glucose metabolism in Han Chinese populations.

Methods:

We genotyped six tag single-nucleotide polymorphisms (SNPs) of GIP and four tag SNPs of glucose-dependent insulinotropic polypeptide receptor (GIPR) among 2884 community-based individuals from Han Chinese populations. Linear analysis was applied to test the associations of these variants with visceral fat area (VFA) and subcutaneous fat area (SFA) quantified by magnetic resonance imaging as well as glucose-related traits.

Results:

We found that the C allele of rs4794008 of GIP tended to increase the VFA and the VFA/SFA ratio in all subjects (P=0.050 and P=0.054, respectively), and rs4794008 was associated with the VFA/SFA ratio in males (P=0.041) after adjusting for the BMI. The VFA-increasing allele of rs4794008 was not related to any glucose metabolism traits. However, rs9904288 of GIP was associated with the SFA in males as well as glucose-related traits in all subjects (P range, 0.004–0.049), and the GIPR variants displayed associations with both fat- and glucose-related traits.

Conclusions:

The results could provide the evidence that GIP might modulate visceral fat accumulation via incretin function or independent of incretin.

Different clinical prognostic factors are associated with improved glycaemic control: findings from MARCH randomized trial

AIMS

Metformin and acarbose have comparable efficacy as initial therapy for HbA_1c reduction in Chinese patients with newly diagnosed Type 2 diabetes. However, not all participants achieved glycaemic control. Our aim was to discover a monotherapy predictor for therapeutic response in Type 2 diabetes on the basis of baseline features.

METHODS

Data from the MARCH trial were collected, resulting in 698 individuals being available for longitudinal analyses. All participants were divided into subgroups based on successful and unsuccessful achievement of the glycaemic target according to primary endpoints at week 24 (HbA_1c < 53 mmol/mol; 7.0%). Logistic regression analysis with stepwise variable selection was performed to assess the independent risk factors for good glycaemic control of monotherapy with metformin or acarbose.

RESULTS

Median HbA_1c was 66 ± 1 mmol/mol (8.2 ± 0.07%) in the metformin group at baseline, and 66 ± 1 mmol/mol (8.2 ± 0.07%) in the acarbose group. After 24 weeks of monotherapy, 79.8% of participants in the metformin group achieved glycaemic targets compared with 78.7% of those in the acarbose group. Multivariate regression analysis showed that BMI and fasting blood glucose were significant independent predictors for the maintenance of good glycaemic control in the metformin group, whereas phase I insulin secretion (Insulin/Glucose at 30 min, I30/G30) and duration of diabetes were associated with good glycaemic control in the acarbose group.

CONCLUSIONS

For newly diagnosed Type 2 diabetes, some clinical features and laboratory parameters are important prognostic factors for predicting drug responsiveness. Participants with a higher BMI and lower fasting blood glucose achieved good glycaemic control when metformin was selected as the initial treatment. Acarbose was best for participants with higher phase I insulin secretion (I30/G30) and shorter duration of Type 2 diabetes.

MiR-214 regulates oral cancer KB cell apoptosis through targeting RASSF5

Ras association domain family member 5 (RASSF5), a member of the Ras association domain family, induces cell apoptosis by phosphorylating FOXO3a, which triggers target gene BIM (pro-apoptotic factor) activation. MiR-214 is overexpressed in oral cancer tissue, indicating its possible involvement in oral cancer pathogenesis. Bioinformatics analysis has revealed a complimentary sequence between miR-214 and the 3'-UTR of RASSF5 mRNA. However, whether miR-124 regulates RASSF5 in oral cancer remains poorly understood. We aimed to investigate the role of miR-214 in RASSF5 expression regulation in oral cancer. Tumor and paracarcinoma tissues were obtained from 48 oral cancer patients to examine miR-214 and RASSF5 expression. The relationship between miR-214 and RASSF5 was investigated by dual luciferase reporter gene assay. Oral cancer KB cells were cultured in vitro and divided into inhibitor NC, miR-214 inhibitor, Scramble-pMD18, RASSF5-pMD18, and miR-214 inhibitor + RASSF5-pMD18 groups. Caspase 3 activity, cell apoptosis, and total protein expression were measured by spectrophotometry, flow cytometry, and western blot, respectively. MiR-214 expression was significantly increased, while that of RASSF5 decreased in oral cancer tumor tissues compared to paracarcinoma tissues. Luciferase assay showed that miR-214 suppressed RASSF5 expression by targeting its 3'-UTR. Down-regulation of miR-214 and/or enhancement of RASSF5 expression markedly increased FOXO3a phosphorylation, BIM expression, caspase 3 activity, and apoptosis. In conclusion, miR-214 expression was elevated and RASSF5 was down-regulated in oral cancer. Moreover, miR-214 regulated KB cell apoptosis through targeted inhibition of RASSF5 expression, FOXO3a phosphorylation, and BIM expression, suggesting its possible application as a novel therapeutic oral cancer target.

Contribution of fibroblast growth factor 23 to Framingham risk score for identifying subclinical atherosclerosis in Chinese men

BACKGROUND AND AIMS

Fibroblast growth factor 23 (FGF23) was demonstrated to be involved in the occurrence and development of cardiovascular disease (CVD). The goal of the present study was to investigate the relationship between serum FGF23 levels and carotid intima-media thickness (C-IMT) in men with a low-to-moderate CVD risk.

METHODS AND RESULTS

Subjects with normal kidney function were selected from the Shanghai Obesity Study. Serum FGF23 levels were determined by sandwich enzyme-linked immunosorbent assay. C-IMT was measured by ultrasonography. The Framingham risk score (FRS) was used to assess CVD risk. A total of 392 men with low CVD risk and 372 men with moderate CVD risk were enrolled. The recognition rate of an elevated C-IMT was 85.66% with the combination of a moderate CVD risk and high serum FGF23 levels, which was greater than that with either parameter alone (65.44% and 61.03%, respectively). Subjects with high serum FGF23 levels, and either low or moderate CVD risk, were more likely to have elevated C-IMT than those with low serum FGF23 levels and low CVD risk (P = 0.014 and 0.001, respectively). The serum FGF23 levels were independently and positively associated with C-IMT in subjects with low or moderate CVD risk (both P = 0.007).

CONCLUSION

In men with low-to-moderate CVD risk, serum FGF23 levels were associated independently and positively with C-IMT. As a complementary index, serum FGF23 levels strengthen the capacity of the FRS to identify subclinical atherosclerosis.

[Efficacy of esophageal cancer screening in high risk population: results of 105 561 subjects in Sichuan province]

Objective: To analyze the efficacy of endoscopic screening for esophageal cancer in high risk population from high risk areas in order to provide scientific basis for evaluation of the results of early diagnosis and treatment of esophageal cancer. Methods: Ten high incidence cities and counties of esophageal cancer in Sichuan province were included in this study. Subjects aged 40-69 years were selected to participate in the endoscopic screening based on the cluster sampling, and the screening-positive subjects were further confirmed by pathological examination. Results: A total of 105 561 subjects were screened during 2006-2014 in 10 cities and counties in Sichuan Province. The detection rate of precancerous lesions was 5.53% (5 841/105 561), and the positive detection rate was 1.13% (1 193/105 561). The overall detection rates of low-grade hyperplasia, moderate hyperplasia, high-grade hyperplasia/carcinoma in situ, early esophageal cancer and invasive carcinoma were 3.87% (4 089/105 561), 1.66% (1 752/105 561), 0.77% (816/105 561), 0.08% (84/105 561) and 0.28% (293/105 561), respectively. The detection rates of all lesions in males were significantly higher than those in females (P<0.05), and were gradually increased with age (P<0.05). Conclusions: At these ten cities and counties in Sichuan Province with high incidence of esophageal cancer, the endoscopic screening has good effect. There are considerable numbers of patients aged 40-69 with precancerous lesions from the high risk areas. Improving the follow-up work of the population with precancerous lesions will achieve better results of early diagnosis and early treatment.

Prevalence and risk of diabetes based on family history in the Shanghai High-Risk Diabetic Screen (SHiDS) study

AIMS

To evaluate the prevalence and risk of diabetes based on family history in high-risk subjects and also to evaluate insulin sensitivity and insulin secretion in these subjects.

METHODS

Data were analysed from 9756 participants in the Shanghai High-Risk Diabetic Screen (SHiDS) Project. Family history of diabetes was classified according to parental and sibling diabetes status. The prevalence and odds ratios were calculated for each grouping after adjusting for other risk factors. Insulin resistance and sensitivity were evaluated using oral glucose tolerance test-derived indices that were validated by hyperinsulinaemic-euglycaemic and hyperglycaemic clamps.

RESULTS

A total of 30.4% of the subjects had a family history of diabetes in a first-degree relative. The proportions of subjects with a father, mother or sibling with diabetes were 7.5, 11.9 and 5.5%, respectively. The prevalence rates of diabetes in subjects with sibling history, maternal history or paternal history of diabetes were 39.3, 38.3 and 36.4%, respectively. Sibling history was a strong risk factor for diabetes (odds ratio 1.53, 95% CI 1.27-1.84; P < 0.05). Insulin secretion was significantly lower in those with a maternal or sibling history of diabetes; however, insulin sensitivity was not significantly different among subjects with a family history of diabetes.

CONCLUSIONS

Sibling history of diabetes was more strongly associated with diabetes risk than parental history among high-risk subjects. Subjects with a sibling or maternal history of diabetes had significantly lower insulin secretion. Sibling history is an important and independent risk factor for diabetes even among multi-risk populations. Those with a sibling history of diabetes warrant intensive care and follow-up screening.

Biochemical Methods to Monitor Autophagic Responses in Plants

The study of autophagy in plants is rapidly increasing, due to its pivotal and fundamental roles in responding to stressful stimuli, recycling nutrients during senescence, and maintaining growth under normal conditions. Assays for detecting autophagy in plants have generally been based on microscopic observations, providing qualitative information on autophagy activity. Here, we discuss biochemical assays for detecting autophagy, which have the potential for providing more quantitative information, with a focus on immunoblotting with antibodies against ATG8, NBR1, or epitope tags fused to ATG proteins.

Shape-dependent cellular behaviors and relaxivity of iron oxide-based T1 MRI contrast agents

Recent research efforts about iron oxide nanoparticles has focused on the development of iron oxide-based T₁ contrast agents for magnetic resonance imaging (MRI), such as ultrasmall iron oxide nanospheres (USNPs <4 nm) and ultrathin nanowires (NW, diameter <4 nm). In this paper, we report the cellular uptake behaviors of these two types of ultrasmall scale nanostructures on HepG2 cells. Both these two nanostructures were functionalized with tannic acid and their physical and chemical properties were carefully analyzed before cellular tests. Both USNPs and NWs exhibited strong paramagnetic signals, a property suitable for T₁ MRI contrast agents. The distinct shapes also caused much difference in their cellular uptake behaviors. Specifically, the uptake of USNPs was five times higher than that of NWs after 72 hours incubation. The shape-dependent cellular uptake can potentially lead to different blood circulation times, and subsequently different applications of these two types of ultrasmall nanostructures.

Association of polymorphisms in intron 2 of FGFR2 and breast cancer risk in Сhinese women

Recent genome-wide association studies (GWAS) demonstrated that genetic variation in intron 2 of fibroblast growth factor receptor 2 (FGFR2) was a novel risk for breast cancer. We investigated whether two SNPs rs1219648 and rs2981582 in intron 2 of FGFR2 were associated with the risk of breast cancer in Chinese women. A total of 340 female breast cancer patients and 400 normal age-matched controls were recruited. Two SNPs were genotyped using matrix-assisted laser desorption/ionization mass spectrometry. The two SNPs rs1219648 and rs2981582 showed no association with the risk of breast cancer. A subgroup analysis by menopausal status demonstrated that the distribution of rs2981582 T alleles, including CT and TT genotypes, was significantly higher in premenopausal patients compared with postmenopausal patients. The TT genotype in rs2981582 was more strongly associated with ER-positive than with ER-negative tumors by ER status analysis. Analysis by haplotypes showed that no haplotypes associated with breast cancer. The results showed no association between two SNPs, rs1219648 and rs2981582 and breast cancer risk, although in a stratified analysis rs2981582 strongly associated with premenopausal and ER-positive breast cancer patients in Chinese women.

N1-guanyl-1,7-diaminoheptane enhances the chemosensitivity of NSCLC cells to cetuximab through inhibition of eukaryotic translation initiation factor 5A2 activation

OBJECTIVE

N1-guanyl-1, 7-diaminoheptane (GC7), an inhibitor of deoxyhypusine synthase has been shown to exhibit significant anti-cancer activity. However, the biological role of eukaryotic translation initiation factor 5A2 activation (EIF5A2) and GC7 on drug resistance in non-small cell lung cancer (NSCLC) has not been investigated. In this study, we aimed to investigate the therapeutic effect of GC7 combined with cetuximab in NSCLC therapy.

MATERIALS AND METHODS

The current study used cell viability assays, EdU incorporation assays, and western blot to detect that the GC7 exhibited synergistic cytotoxicity with cetuximab in NSCLC.

RESULTS

CCK-8 assays showed that combined treatment with GC7 and cetuximab significantly inhibited the viabilities in three NSCLC cell lines. In addition, EdU incorporation assays also indicated that GC7 co-treatment remarkably enhanced the cetuximab sensitivity in NSCLC cells. Nevertheless, down-regulation of EIF5A2 diminished the regulatory role of GC7 in cetuximab cytotoxicity. Western blot showed that transfection of EIF5A2 siRNA significantly suppressed the protein expression of EIF5A2 in NSCLC cells.

CONCLUSIONS

These findings demonstrate that combined treatment with GC7 could enhance cetuximab sensitivity by inhibiting EIF5A2 in NSCLC cells, implying the potential clinical application of GC7 in cetuximab-based chemotherapy for NSCLC patients.

Incidence, Risk Factors, and the Protective Effect of High Body Mass Index against Sarcopenia in Suburb-Dwelling Elderly Chinese Populations

BACKGROUND

Few studies have explored the risk factors of sarcopenia in certain cohorts. The objective of this study was to examine the incidence of sarcopenia and associated factors over a 1-year period in an elderly Chinese suburban population.

METHODS

This study was conducted on 356 Chinese suburb-dwelling participants aged ≥60 years, for whom detailed information regarding sociodemographics, behavioral characteristics, and medical conditions had been documented. Sarcopenia was defined according to the Asian Working Group for Sarcopenia (AWGS) criteria. Sarcopenia incidence was documented after one year of follow-up, and correlated with several possible factors.

RESULTS

At baseline, 64 (9.7%) of the initial 657 participants had sarcopenia. The prevalence of sarcopenia was 10.4% after one year. Between baseline and 1-year follow-up, 13 of the participants without sarcopenia at baseline had developed sarcopenia. After multivariate adjustments, it was found that the incidence of sarcopenia increased with age and high body mass index (BMI) is associated with less incidence of sarcopenia. Incidence was also higher among women.

CONCLUSIONS

We found sarcopenia incidence increased with age, and women were more likely to have sarcopenia. A higher BMI is also associated with a lower incidence of sarcopenia. Maintaining a healthy weight could be beneficial in the prevention of sarcopenia.

Decreased miR-134 expression and its tumor-suppressive function in human osteosarcoma

Dysregulation of microRNA (miR) is often associated with cancer development and progression. Aberrant expression of miR-134 has been found in some types of cancer. However, its expression and function in osteosarcoma remain unclear. The aim of this study was to explore the effects of miR-134 in osteosarcoma tumorigenesis and development. The expression level of miR-134 was quantified by real-time reverse transcription-polymerase chain reaction in human osteosarcoma cell lines and tissues. The effects of miR-134 on MG-63 cell phenotypes and tumorigenicity in vivo were observed using flow cytometry, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide, transwell invasion, migration, and scratch migration assays. MiR-134 was significantly downregulated in osteosarcoma cell lines and clinical specimens. Decreased miR-134 expression was significantly associated with large tumor size, positive distant metastasis, and advanced clinical stage. Low miR-134 expression in osteosarcoma was an independent predictor of poor survival. Overexpression of miR-134 inhibited MG-63 cell proliferation, invasion, and migration, promoted cell apoptosis in vitro, and suppressed tumorigenicity in vivo. These findings indicate that miR-134 may act as a tumor suppressor in osteosarcoma and could serve as a novel therapeutic agent for miRNA-based therapy.

Overexpression of a Populus trichocarpa H+-pyrophosphatase gene PtVP1.1 confers salt tolerance on transgenic poplar

The Arabidopsis vacuolar H(+)-pyrophosphatase (AVP1) has been well studied and subsequently employed to improve salt and/or drought resistance in herbaceous plants. However, the exact function of H(+)-pyrophosphatase in woody plants still remains unknown. In this work, we cloned a homolog of type I H(+)-pyrophosphatase gene, designated as PtVP1.1, from Populus trichocarpa, and investigated its function in both Arabidopsis and poplar. The deduced translation product PtVP1.1 shares 89.74% identity with AVP1. Semi-quantitative reverse transcription polymerase chain reaction (RT-PCR) and quantitative real-time PCR analyses revealed a ubiquitous expression pattern of PtVP1.1 in various tissues, including roots, stems, leaves and shoot tips. Heterologous expression of PtVP1.1 rescued the retarded-root-growth phenotype of avp1, an Arabidopsis knock out mutant of AVP1, on low carbohydrate medium. Overexpression of PtVP1.1 in poplar (P. davidiana × P. bolleana) led to more vigorous growth of transgenic plants in the presence of 150 mM NaCl. Microsomal membrane vesicles derived from PtVP1.1 transgenic plants exhibited higher H(+)-pyrophosphatase hydrolytic activity than those from wild type (WT). Further studies indicated that the improved salt tolerance was associated with a decreased Na(+) and increased K(+) accumulation in the leaves of transgenic plants. Na(+) efflux and H(+) influx in the roots of transgenic plants were also significantly higher than those in the WT plants. All these results suggest that PtVP1.1 is a functional counterpart of AVP1 and can be genetically engineered for salt tolerance improvement in trees.