Abstract P1-08-04: Not presented

This abstract was not presented at the symposium.

Genome-wide DNA methylation profiling of articular cartilage reveals significant epigenetic alterations in Kashin-Beck disease and osteoarthritis

OBJECTIVE

To determine genome-wide DNA methylation profiles of knee cartilage from patients with Kashin-Beck disease (KBD) and osteoarthritis (OA).

METHOD

Knee cartilage was collected from 14 grade III KBD patients, 5 primary OA patients and 13 healthy subjects. The genome-wide methylation profiles of 5 KBD cartilage, 5 OA cartilage and 5 normal cartilage were determined by Illumina HumanMethylation450 array. Illumina Methylation Analyzer package was employed for identifying differentially methylated CpG sites. Functional annotation and enrichment analysis of differentially methylated genes (DMG) were conducted using GeneRIF database, Ingenuity Pathway Analysis (IPA) and The Database for Annotation, Visualization and Integrated Discovery (DAVID). Mass spectrometry (MS) and immunohistochemistry (IHC) were conducted to validate the functional relevance of identified KBD associated gene.

RESULTS

We identified a total of 1212 differentially methylated CpG sites in KBD vs Normal, annotated to 264 hypermethylated and 368 hypomethylated genes. Comparing the DNA methylation profiles of KBD vs Normal and OA vs Normal detected overlap of 367 differentially methylated CpG sites (annotated to 182 genes) as well as 845 KBD-specific differentially methylated CpG sites (annotated to 471 unique genes). MS and IHC confirmed the hypermethylation status and decreased protein expression of HAPLN1 gene in KBD cartilage.

CONCLUSION

Our data implicate epigenetic dysregulation of a host of genes in KBD and OA. Furthermore, we observed common causal epigenetic changes shared by KBD and OA.

Integrative analysis of GWAS, eQTLs and meQTLs data suggests that multiple gene sets are associated with bone mineral density

Objectives

Several genome-wide association studies (GWAS) of bone mineral density (BMD) have successfully identified multiple susceptibility genes, yet isolated susceptibility genes are often difficult to interpret biologically. The aim of this study was to unravel the genetic background of BMD at pathway level, by integrating BMD GWAS data with genome-wide expression quantitative trait loci (eQTLs) and methylation quantitative trait loci (meQTLs) data

Method

We employed the GWAS datasets of BMD from the Genetic Factors for Osteoporosis Consortium (GEFOS), analysing patients’ BMD. The areas studied included 32 735 femoral necks, 28 498 lumbar spines, and 8143 forearms. Genome-wide eQTLs (containing 923 021 eQTLs) and meQTLs (containing 683 152 unique methylation sites with local meQTLs) data sets were collected from recently published studies. Gene scores were first calculated by summary data-based Mendelian randomisation (SMR) software and meQTL-aligned GWAS results. Gene set enrichment analysis (GSEA) was then applied to identify BMD-associated gene sets with a predefined significance level of 0.05.

Results

We identified multiple gene sets associated with BMD in one or more regions, including relevant known biological gene sets such as the Reactome Circadian Clock (GSEA p-value = 1.0 × 10^-4 for LS and 2.7 × 10^-2 for femoral necks BMD in eQTLs-based GSEA) and insulin-like growth factor receptor binding (GSEA p-value = 5.0 × 10^-4 for femoral necks and 2.6 × 10^-2 for lumbar spines BMD in meQTLs-based GSEA).

Conclusion

Our results provided novel clues for subsequent functional analysis of bone metabolism, and illustrated the benefit of integrating eQTLs and meQTLs data into pathway association analysis for genetic studies of complex human diseases.

Cite this article: W. Wang, S. Huang, W. Hou, Y. Liu, Q. Fan, A. He, Y. Wen, J. Hao, X. Guo, F. Zhang. Integrative analysis of GWAS, eQTLs and meQTLs data suggests that multiple gene sets are associated with bone mineral density. Bone Joint Res 2017;6:572–576.

The Mealiness and Quality of Herbal Medicine: Licorice for Example

Background:

The morphological identification is an effective and simple quality evaluation method in Chinese drugs, and the traits of mealiness and color were widely used in the commercial market of Chinese drugs.

Objective:

The objective of this study was to explore the correlation between mealiness of herbal drugs and its quality; licorice was selected as an example.

Materials and Methods:

The mealiness of licorice was graded by its weight; meanwhile, the content of glycyrrhizic acid and liquiritin was determined by high-performance liquid chromatography-diode-array detection method; the content of polysaccharides, soluble sugars, pectin, total starch, amylose, and amylopectin was measured by colorimetric method; and the number and diameter of starch granule were observed by microscope.

Results:

The results showed that the mealiness of licorice which collected from wild and cultivated plants is positively correlated with the content of glycyrrhizic acid, liquiritin, the ratio of amylose to total starch, and the number of starch granules whose diameter was over 5 μm. However, the mealiness is negatively correlated with the total starch. Further, the formation mechanism of starch granule was discussed.

Conclusion:

It is for the first time to report the positive correlation between the mealiness and the starch granule size, the ratio of amylose to total starch, which can provide rationality for the quality evaluation using the character of mealiness in herbal medicine.

SUMMARY

It is a convenient method to justify the quality of herbal medicine. To explore the correlation between mealiness of herbal drugs and its quality, licorice was selected as an example. The result indicated that the effective constituent is correlated with mealiness of licorice.

Abbreviations Used: TCM: Traditional Chinese Medicine.

Decreased serum vitamin D levels in early spontaneous pregnancy loss

Background/Objectives:

Effects of vitamin D deficiency in pregnancy have been associated with some adverse pregnancy outcomes. The objective of this study was to analyze the relationship between vitamin D deficiency in childbearing aged women and pregnancy loss (PL) in the first trimester.

Subjects/Methods:

This is a cross-sectional study. Plasma was collected from 60 nulliparous women with singleton at 7–9 weeks of gestation (30 with viable gestation and 30 with PL) and 60 non-gravid childbearing aged women (30 with a successful pregnancy history, and 30 with one or more spontaneous first-trimester PL history). Quantitation of serum 25-hydroxyvitamin D (25(OH)D) and 25-hydroxyvitamin D-1 alpha hydroxylase (CYP27B1) was assayed.

Results:

By pregnancy/non-gravid, normal pregnant women had higher 25(OH)D (49.32 μg/l) and CYP27B1 (82.00 pg/ml) than PL women (34.49 μg/l and 37.87 pg/ml, both P<0.01); the non-gravid women with a successful pregnancy history also had higher 25(OH)D (39.56 μg/l) and CYP27B1 (39.04 pg/ml) than women with PL history (12.30 μg/l and 12.35 pg/ml, both P<0.01). The 96.7% of non-gravid women with PL history and 43.3% of PL women had serum 25(OH)D concentrations below 30 μg/l. There was a strong association between low vitamin D levels and PL (odds ratio 1.71; 95% confidence interval: 1.2–2.4, P<0.001). The regression analyses showed that PL was significantly inversely correlated with 25(OH)D (P<0.01) and CYP27B1 levels (P<0.01).

Conclusions:

Vitamin D deficiency associated with PL in the first trimester of pregnancy. Decreased serum vitamin D levels among childbearing aged women with the failed clinical pregnancies history may predispose to increased risk for PL.

Ferroptosis: process and function

Ferroptosis is a recently recognized form of regulated cell death. It is characterized morphologically by the presence of smaller than normal mitochondria with condensed mitochondrial membrane densities, reduction or vanishing of mitochondria crista, and outer mitochondrial membrane rupture. It can be induced by experimental compounds (e.g., erastin, Ras-selective lethal small molecule 3, and buthionine sulfoximine) or clinical drugs (e.g., sulfasalazine, sorafenib, and artesunate) in cancer cells and certain normal cells (e.g., kidney tubule cells, neurons, fibroblasts, and T cells). Activation of mitochondrial voltage-dependent anion channels and mitogen-activated protein kinases, upregulation of endoplasmic reticulum stress, and inhibition of cystine/glutamate antiporter is involved in the induction of ferroptosis. This process is characterized by the accumulation of lipid peroxidation products and lethal reactive oxygen species (ROS) derived from iron metabolism and can be pharmacologically inhibited by iron chelators (e.g., deferoxamine and desferrioxamine mesylate) and lipid peroxidation inhibitors (e.g., ferrostatin, liproxstatin, and zileuton). Glutathione peroxidase 4, heat shock protein beta-1, and nuclear factor erythroid 2-related factor 2 function as negative regulators of ferroptosis by limiting ROS production and reducing cellular iron uptake, respectively. In contrast, NADPH oxidase and p53 (especially acetylation-defective mutant p53) act as positive regulators of ferroptosis by promotion of ROS production and inhibition of expression of SLC7A11 (a specific light-chain subunit of the cystine/glutamate antiporter), respectively. Misregulated ferroptosis has been implicated in multiple physiological and pathological processes, including cancer cell death, neurotoxicity, neurodegenerative diseases, acute renal failure, drug-induced hepatotoxicity, hepatic and heart ischemia/reperfusion injury, and T-cell immunity. In this review, we summarize the regulation mechanisms and signaling pathways of ferroptosis and discuss the role of ferroptosis in disease.

Restoration of images degraded by underwater turbulence using structure tensor oriented image quality (STOIQ) metric

Recent advances in image processing for atmospheric propagation have provided a foundation for tackling the similar but perhaps more complex problem of underwater imaging, which is impaired by scattering and optical turbulence. As a result of these impairments underwater imagery suffers from excessive noise, blur, and distortion. Underwater turbulence impact on light propagation becomes critical at longer distances as well as near thermocline and mixing layers. In this work, we demonstrate a method for restoration of underwater images that are severely degraded by underwater turbulence. The key element of the approach is derivation of a structure tensor oriented image quality metric, which is subsequently incorporated into a lucky patch image processing framework. The utility of the proposed image quality measure guided by local edge strength and orientation is emphasized by comparing the restoration results to an unsuccessful restoration obtained with equivalent processing utilizing a standard isotropic metric. Advantages of the proposed approach versus three other state-of-the-art image restoration techniques are demonstrated using the data obtained in the laboratory water tank and in a natural environment underwater experiment. Quantitative comparison of the restoration results is performed via structural similarity index measure and normalized mutual information metric.

Blind image quality assessment via deep learning

This paper investigates how to blindly evaluate the visual quality of an image by learning rules from linguistic descriptions. Extensive psychological evidence shows that humans prefer to conduct evaluations qualitatively rather than numerically. The qualitative evaluations are then converted into the numerical scores to fairly benchmark objective image quality assessment (IQA) metrics. Recently, lots of learning-based IQA models are proposed by analyzing the mapping from the images to numerical ratings. However, the learnt mapping can hardly be accurate enough because some information has been lost in such an irreversible conversion from the linguistic descriptions to numerical scores. In this paper, we propose a blind IQA model, which learns qualitative evaluations directly and outputs numerical scores for general utilization and fair comparison. Images are represented by natural scene statistics features. A discriminative deep model is trained to classify the features into five grades, corresponding to five explicit mental concepts, i.e., excellent, good, fair, poor, and bad. A newly designed quality pooling is then applied to convert the qualitative labels into scores. The classification framework is not only much more natural than the regression-based models, but also robust to the small sample size problem. Thorough experiments are conducted on popular databases to verify the model's effectiveness, efficiency, and robustness.

RAGE is essential for oncogenic KRAS-mediated hypoxic signaling in pancreatic cancer

A hypoxic tumor microenvironment is characteristic of many cancer types, including one of the most lethal, pancreatic cancer. We recently demonstrated that the receptor for advanced glycation end products (RAGE) has an important role in promoting the development of pancreatic cancer and attenuating the response to chemotherapy. We now demonstrate that binding of RAGE to oncogenic KRAS facilitates hypoxia-inducible factor 1 (HIF1)α activation and promotes pancreatic tumor growth under hypoxic conditions. Hypoxia induces NF-κB-dependent and HIF1α-independent RAGE expression in pancreatic tumor cells. Moreover, the interaction between RAGE and mutant KRAS increases under hypoxia, which in turn sustains KRAS signaling pathways (RAF-MEK-ERK and PI3K-AKT), facilitating stabilization and transcriptional activity of HIF1α. Knock down of RAGE in vitro inhibits KRAS signaling, promotes HIF1α degradation, and increases hypoxia-induced pancreatic tumor cell death. RAGE-deficient mice have impaired oncogenic KRAS-driven pancreatic tumor growth with significant downregulation of the HIF1α signaling pathway. Our results provide a novel mechanistic link between NF-κB, KRAS, and HIF1α, three potent molecular pathways in the cellular response to hypoxia during pancreatic tumor development and suggest alternatives for preventive and therapeutic strategies.

HIV Tat protein affects circadian rhythmicity by interfering with the circadian system

OBJECTIVES

Sleep disorders are common in patients with HIV/AIDS, and can lead to poor quality of life. Although many studies have investigated the aetiology of these disorders, it is still unclear whether impaired sleep quality is associated with HIV itself, social problems, or side effects of antiretroviral therapy (ART). Moreover, despite its known neurological associations, little is known about the role of the trans-activator of transcription (Tat) protein in sleep disorders in patients with HIV/AIDS. The purpose of this study was to test the hypothesis that the sleep quality of patients with HIV/AIDS affected by an altered circadian rhythm correlates with cerebrospinal HIV Tat protein concentration.

METHODS

Ninety-six patients with HIV/AIDS between 20 and 69 years old completed the Pittsburgh Sleep Quality Index. Their circadian rhythm parameters of blood pressure, Tat concentration in cerebrospinal fluid, melatonin concentration, CD4 cell count and HIV RNA viral load in serum were measured.

RESULTS

The circadian amplitude of systolic blood pressure and the score for sleep quality (Pittsburgh Sleep Quality Index) were negatively correlated with HIV Tat protein concentration, while the melatonin value was positively correlated with Tat protein concentration.

CONCLUSIONS

The HIV Tat protein affects circadian rhythmicity by interfering with the circadian system in patients with HIV/AIDS and further increases the melatonin excretion value. A Tat protein-related high melatonin value may counteract HIV-related poor sleep quality during the progression of HIV infection. This study provides the first clinical evidence offering an explanation for why sleep quality did not show an association with progression of HIV infection in previous studies.

The pleiotropic roles of sphingolipid signaling in autophagy

The autophagic process involves encompassing damaged proteins and organelles within double- or multi-membraned structures and delivering these molecules to the lytic compartments of vacuoles. Sphingolipids (SLs), which are ubiquitous membrane lipids in eukaryotes, participate in the generation of various membrane structures, including rafts, caveolae, and cytosolic vesicles. SLs are a complex family of molecules that have a growing number of members, including ceramide, sphingosine-1-phosphate, and dihydroceramide, which have been associated with the essential cellular process of autophagy. This review highlights recent studies focusing on the regulation and function of SL-associated autophagy and its role in cell fate, diseases, and therapeutic interventions.

Strange attractors: DAMPs and autophagy link tumor cell death and immunity

Resistance to ‘apoptotic' cell death is one of the major hallmarks of cancer, contributing to tumor development and therapeutic resistance. Damage-associated molecular patterns (DAMPs) are molecules released or exposed by dead, dying, injured, or stressed non-apoptotic cells, with multiple roles in inflammation and immunity. Release of DAMPs not only contributes to tumor growth and progression but also mediates skewing of antitumor immunity during so-called immunogenic tumor cell death (ICD). Autophagy is a lysosome-mediated homeostatic degradation process in which cells digest their own effete organelles and macromolecules to meet bioenergetic needs and enable protein synthesis. For tumor cells, autophagy is a double-edged sword. Autophagy, in balance with apoptosis, can function as a tumor suppressor; autophagy deficiency, associated with alterations in apoptosis, initiates tumorigenesis in many settings. In contrast, autophagy-related stress tolerance generally promotes cell survival, which enables tumor growth and promotes therapeutic resistance. Most anticancer therapies promote DAMP release and enhance autophagy. Autophagy not only regulates DAMP release and degradation, but also is triggered and regulated by DAMPs. This interplay between autophagy and DAMPs, serving as ‘strange attractors' in the dynamic system that emerges in cancer, regulates the effectiveness of antitumor treatment. This interplay also shapes the immune response to dying cells upon ICD, culling the least fit tumor cells and promoting survival of others. Thus, DAMPs and autophagy are suitable emergent targets for cancer therapy, considering their more nuanced role in tumor progression.

Immunostimulant Activity of a Novel Polysaccharide Isolated from Lactarius deliciosus (L. ex Fr.) Gray

More and more fungal polysaccharides have been reported to exhibit a variety of biological activities, including antitumor, antioxidant and immunostimulant activity. The non-starch polysaccharides have emerged as an important class of bioactive natural products. In this study, the immune activities of a novel polysaccharide (LDG-A) isolated from Lactarius deliciosus (L. ex Fr.) Gray were investigated at 20, 40 and 80 mg/kg dose levels. The inhibitory rate in mice treated with 80 mg/kg LDG-A can reach 68.422%, being the highest in the three doses, which may be comparable to mannatide. Histology of immune organs showed that the tissues were arranged in more regular and firm pattern, but the tumor tissue arranged looser in LDG-A group than those in control group. Meanwhile, there was no obvious damage to other organs, such as heart, lung, and kidney. The antitumor activity of the LDG-A was usually believed to be a consequence of the stimulation of the cell-mediated immune response because it can significantly promote the lymphocyte and macrophage cells in the dose range of 50-200 μg/ml and 100-400 μg/ml in vitro, respectively. The level of cytokines (IL-6, TNF-α, and NO) of macrophage cells induced by LDG-A treatment was similar to lipopolysaccharides at different concentrations. The expression of all these genes studied (TNF-α, IL-6, and iNOS mRNA) in the untreated macrophage was little, but increased dramatically in a dose-dependent manner in the LDG-A-treated cells. The results obtained in the present study indicated that the purified polysaccharide of L. deliciosus (L. ex Fr.) Gray is a potential source of natural immune-stimulating substances.

Overexpression, purification, and pharmacologic evaluation of anticancer activity of ribosomal protein L24 from the giant panda (Ailuropoda melanoleuca)

The ribosomal protein L24 (RPL24) belongs to the L24E family of ribosomal proteins and is located in the cytoplasm. The purpose of this study was to investigate the structure and anti-cancer function of RPL24 of the giant panda (Ailuropoda melanoleuca). The complementary DNA of RPL24 was cloned successfully using reverse transcription-polymerase chain reaction technology. We constructed a recombinant expression vector containing RPL24 complementary DNA and overexpressed it in Escherichia coli using pET28a plasmids. The expression product obtained was purified using Ni-chelating affinity chromatography. The results indicated that the length of the fragment cloned is 509 bp, and it contains an open-reading frame of 474 bp encoding 157 amino acids. Primary structure analysis revealed that the molecular weight of the putative RPL24 protein is 17.78 kDa with a theoretical isoelectric point of 11.86. The RPL24 gene is readily expressed in E. coli, and the RPL24 fused with the N-terminal histidine-tagged protein to give rise to the accumulation of an expected 23.51-kDa polypeptide. The inhibitory rate in mice treated with 0.1 mg/mL RPL24, the highest of 3 doses administered, can reach 67.662%, which may be comparable to the response to mannatide. The histology of organs with tumors showed that the tissues in the RPL24 group displayed a looser arrangement compared with that in the control group. Furthermore, no obvious damage was apparent in other organs, such as heart, lung, and kidney. The data showed that the recombinant RPL24 had time and dose dependency on the cell growth inhibition rate. Human laryngeal carcinoma Hep-2 cells treated with 0.3125-10 µg/mL RPL24 for 24 h displayed significant cell growth inhibition (P < 0.05; N = 6) in assays using 3-(4,5-dimethylthiazol- 2-yl)-2,5-diphenyltetrazolium bromide compared with that in control (untreated) cells. By contrast, human hepatoma Hep G-2 cells displayed no significant change (P > 0.05; N = 6) from control (untreated) cells. RPL24 has time and dose dependency on Hep-2 cell growth inhibition. The data indicate that the effect at low concentrations is better than that at high concentrations, and the concentration of 0.625 µg/mL provides the best rate of growth inhibition. Further research is ongoing to determine the bioactive principles of recombinant RPL24 protein that are responsible for its anticancer activity.

Effect of a carbohydrate-containing late-evening snack on energy metabolism and fasting substrate utilization in adults with acute-on-chronic liver failure due to Hepatitis B

BACKGROUND/OBJECTIVES

This study investigates the effects of a carbohydrate (CHO; lotus-root starch) predominant, late-evening snack (LES), containing 200 kcal (50 g CHO) on fasting resting energy expenditure (REE) and nutrient oxidation in hospitalized adults with acute-on-chronic liver failure (ACLF).

SUBJECTS/METHODS

Adults with ACLF were randomized to receive daily LES (treatment; n=35) or standard care (n=35; non-supplemented control) for 14 days. REE and respiratory quotient (RQ) were measured by indirect calorimetry, nutrient oxidation (CHO, protein and fat), intake and biochemical parameters were measured in both groups at baseline and after 14 days using validated techniques. Disease severity was measured using the model for end-stage liver disease (MELD).

RESULTS

No significant differences in macronutrient intake, anthropometric, demographic characteristics or MELD scores were observed between groups at baseline (P>0.05). Fasting RQ was significantly higher in the LES supplemented verses the control group after 2 weeks (P=0.02). CHO oxidation was significantly higher (P=0.001) and fat oxidation (P=0.02) was lower in the LES-supplemented group when compared with controls after 2 weeks. Fasting RQ and REE in the LES-supplemented group increased significantly (0.83 verses 0.88; P=0.007/1301±409 vs 1687±718 kcal/day; P=0.02) in patients with MELD scores 30 when compared with patients with MELD scores >30 (0.82 verses 0.84; P=0.27/ 1361±405 vs 1437±429 kcal/day; P=0.67) after supplementation.

CONCLUSIONS

A carbohydrate-predominant LES is associated with increases in fasting carbohydrate oxidation, REE and reductions in fat oxidation in adults with ACLF. Therapeutic strategies utilizing LES may promote improved nutritional status in adults with ACLF.

LPS-induced inflammatory response after therapy of aggressive periodontitis

We have reported a lipopolysaccharide (LPS)-induced hyper-inflammatory response in localized aggressive periodontitis (LAP). It is unknown whether treatment is able to modulate this LPS responsiveness. Fifty-nine individuals with LAP were treated by mechanical debridement and systemic antibiotics. Clinical parameters and cyto/chemokine responsiveness of whole blood stimulated with Porphyromonas gingivalis or Escherichia coli LPS were monitored at baseline and 3, 6, and 12 months post-treatment. Overall, clinical parameters were improved following treatment. Additionally, P. gingivalis LPS induction of eotaxin, IFNγ, IL10, IL12p40, IL1β, IL6, IP10, MCP1, MIP1α, GM-CSF, and TNFα was significantly decreased (p < .05). Similarly, induction of eotaxin, INFγ, IL10, IL12p40, GM-CSF, and TNFα by E. coli LPS was also reduced post-treatment. These reductions correlated with decreases in clinical parameters. Importantly, these reductions in LPS responsiveness were most robust at 3 months, and some lost significance at 6 to 12 months post-treatment. In conclusion, LPS-induced hyper-inflammatory response in LAP can be partially modulated by periodontal therapy. Conversely, rebound in the hyper-responsiveness of some mediators, in the presence of improved clinical parameters, suggests that this phenotype could be partially influenced by a genetic trait and play a role in future disease recurrence (ClinicalTrials.gov, NCT01330719).