The Protective Effect of Myristica fragrans Houtt. Extracts Against Obesity and Inflammation by Regulating Free Fatty Acids Metabolism in Nonalcoholic Fatty Liver Disease

Nonalcoholic fatty liver disease (NAFLD) is a disorder characterized by the excess accumulation of fat in the hepatocytes. It is commonly associated with severe obesity and inflammation. Free fatty acids (FFAs) are the key to regulate lipid metabolism and immune response in hepatocyte cells. This study examined the effects of AEN (alcohol extract of nutmeg, the seed of Myristica fragrans Houtt.) on the inhibition of lipid synthesis and inflammation in vitro and in vivo and on high-fat diet-induced obesity in NAFLD mice. Our results showed that AEN treatment could downregulate the expression of lipid synthesis-related genes fatty acid synthase (FASN) and sterol regulatory element-binding protein 1c (SREBP-1c) and lower the lipid content of cells. AEN also inhibited FFAs-mediated inflammation-related cytokines interleukin-6 (IL-6) and tumor necrosis factor α (TNFα) expression in cells. In a mouse model, AEN reduced the bodyweight of obese mice and improved NAFLD without affecting food intake. Further analysis revealed that AEN significantly reduced inflammation level, cholesterol and lipid accumulation, blood glucose, and other liver function indexes in mice fed with a high-fat diet. In conclusion, AEN inhibited the aggravation of obesity and inflammation by downregulating lipid-gene expression in the liver to ameliorate NAFLD.

Effects of glucocorticoids on osteoporosis in rheumatoid arthritis: a systematic review and meta-analysis

We evaluated the effects of glucocorticoids on bone mineral density (BMD), and prevalence of osteoporosis and fracture in rheumatoid arthritis (RA) by meta-analysis. Until June 26, 2019, we conducted a systematic literature search in EMBASE, Web of science, PubMed, and Cochrane Library to obtain BMD and the prevalence of osteoporosis and fracture in glucocorticoid-treated subjects with RA. The BMD of the treatment and control groups were analyzed by meta-analysis (Stata. version 15), and the 95% confidence interval (CI) was calculated. We identified 15 observational studies, including 46,711 RA subjects and 857 healthy controls. The BMD of the lumbar spine (- 0.038 g/cm²; CI, - 0.052, - 0.024) and femoral neck (- 0.017 g/cm²; - 0.030, - 0.003) in RA treated with glucocorticoids were significantly lower than those in RA controls. Compared with healthy control group, the BMD of the lumbar spine (- 0.094 g/cm²; - 0.126, - 0.061) and femoral neck (- 0.097 g/cm², - 0.109, - 0.085) of RA treated with glucocorticoids decreased more significantly. The prevalence of osteoporosis in whole body, spine, and femur was 38.6% (0.305, 0.466), 32.9% (0.277, 0.381), and 21.7% (0.106, 0.328), respectively. And the prevalence of vertebral fracture was 13.0% (0.058, 0.203). Glucocorticoids may lead to a decline in skeletal health in subjects with RA, especially in vertebral and femoral BMD, compared with normal people or RA without glucocorticoid therapy. Meanwhile, osteoporosis and fractures were also common. Therapeutic measures should be targeted at individuals, which needs further study. Through meta-analysis, we found that glucocorticoids have some negative effects on the bone health of subjects with rheumatoid arthritis. Therefore, when using glucocorticoids to treat rheumatoid arthritis, we should take strategic measures to prevent the decline of bone quality.

AB1331-HPR ACTIVE DISEASE ACTIVITY IN ANKYLOSIS SPONDYLITIS: WORSE OUTCOMES AND POORER HR-QOL

Background:

Ankylosing spondylitis (AS) is a chronic inflammatory disease that mainly affects the sacroiliac joints and the spine, resulting in decline in quality of life[1,2]. Poor QoL is significantly related to high disease activity[3]. However, there is no systematic report on which prognosis indicators are affected by disease activity in AS patients.

Objectives:

This study aimed to evaluate the patient-reported outcome measures and health-related quality of life (HR-QoL) in AS patients defined on the basis of the Bath Spondylitis Ankylosing Disease Activity Index (BASDAI).

Methods:

204 AS patients were involved in this study. A serious of questionnaires were used to overall assess AS patients, which include: Bath Ankylosing Spondylitis Disease Activity Index (BASDAI), Bath Ankylosing Spondylitis Metrology Index (BASMI), Bath Ankylosing Spondylitis Functional Index (BASFI), the 10 cm Visual Analog Scale (VAS), the Self-Rating Anxiety Scale (SAS), the Self-Rating Depression Scale (SDS), the Pittsburgh Sleep Quality Index (PSQI), the Health Assessment Questionnaire-Disability Index (HAQ-DI), the Fatigue Severity Scale(FSS) and the Short Form 36 Health Survey (SF-36). Independent samples t-test, Mann–Whitney U-test, Chi-square analysis and Pearson /Spearman correlation were used to analyze the data.

Results:

The results demonstrated 31.4% AS patients were in active disease activity stage. Active AS patients were older, unemployed, and had less exercise therapy than stable AS patients. Besides, AS patients with active disease activity presented more severe pain(P<0.001), poor physical function(P<0.001) and spinal mobility(P<0.001). They were more anxious(P<0.001), depressed(P<0.001) and had more sleep disturbance(P=0.001). Compared with active AS patients, stable AS patients had more leukocytes(P=0.040), lymphocytes(P=0.002), erythrocytes(P=0.001) and hemoglobin(P<0.001). Active disease activity had a significant impact on all dimensions of quality of life in AS patients(P<0.001).

Conclusion:

These findings suggested that medical personnel should pay more attention to active AS patients and make effective interventions to improve quality of life.

References:

[1]Exarchou S, Lindstrom U, Askling J, Eriksson JK, Forsblad-d’Elia H, Neovius M, Turesson C, Kristensen LE, Jacobsson LT (2015) The prevalence of clinically diagnosed ankylosing spondylitis and its clinical manifestations: a nationwide register study. Arthritis research & therapy 17:118. doi:10.1186/s13075-015-0627-0

[2]Qian Q, Xu X, He H, Ji H, Zhang H, Ding Y, Dai SM, Zou Y, Zhu Q, Yang C, Ye S, Jiang L, Tang JP, Tong Q, He D, Zhao D, Li Y, Ma Y, Zhou J, Yuan Z, Zhang J, Jin L, Zhou X, Reveille JD, Zou H, Wang J (2017) Clinical patterns and characteristics of ankylosing spondylitis in China. Clinical rheumatology 36 (7):1561-1568. doi:10.1007/s10067-017-3660-3

[3]Huang JC, Qian BP, Qiu Y, Wang B, Yu Y, Zhu ZZ, Hu J, Qu Z (2017) Quality of life and correlation with clinical and radiographic variables in patients with ankylosing spondylitis: a retrospective case series study. BMC musculoskeletal disorders 18 (1):352. doi:10.1186/s12891-017-1711-1

Acknowledgments:

Thanks to all the authors for their efforts and thanks to all members of the Department of Rheumatology of Affiliated Hospital of Nantong University for their helpfulness in the acquisition of data.

Disclosure of Interests:

None declared

THU0044 SINGLE CELL ANALYSIS OF BONE MARROW AND PERIPHERAL ALTERED B CELL DIFFERENTIATION IN PATIENTS WITH ACTIVE SLE AND THE MECHANISM OF ABNORMAL EARLY B CELL DEVELOPMENT

Background:

B cell differentiation and dysfunction play a key role in the pathogenesis of Systemic lupus erythematosus (SLE). Bone marrow (BM) is the development organ of B cells, and also the home and residence place of plasma cells and memory B cells. However, there is a lack of studies on B cells in BM with lupus.

Objectives:

To map the development of BM and peripheral B cells and investigate the mechanism of abnormal early B cell development in SLE.

Methods:

A total of 11 SLE patients and 5 age- and sex-matched controls were recruited.BM and peripheral B cell subsets were measured by flow cytometry. sorting-purified B cell subsets were subject toSingle-cell RNA sequencing (scRNA-seq) and functional studies. Plasma cytokines and secreted immunoglobulins were detected by Luminex or ELISA. Disease activity of SLE patients was measured using the SLE Disease Activity Index (SLEDAI).

Results:

In the present study, we find out that the percentage of monocytes in MNC (p=0.070) and plasma cells(p=0.001)in CD19+ were significantly decreased in BM of SLE, compared to healthy controls. While, SLE patients had increased T%MNC(p=0.008) and B%CD19+(p=0.002) in BM that controls. In detail, the B cell subsets of bone marrow in patients with active lupus (SLEDAI≥8 score) were seriously disordered, showing the increasing T%MNC(p=0.049), propre-B%CD19+ (p=0.006)and immature B cell%CD19+ (p=0.010) than healthy donors. propre-B%CD19+ exhibited good relationship with SLEDAI. By integrating single B cell expression profiling and repertoire analysis, we map the development of B cells in BM and peripheral and pathogenic characteristics of early B cells, especially propre-B.

Conclusion:

These findings demonstrated that early B cells in BM, especially propre-B are abnormally differentiated with dysregulations. BM is an important organ targeted by SLE. This studyis not only to clarify the internal mechanism of the disorder of differentiation of B cells, but also to provide new clues for the targeted diagnosis and treatment of SLE.

References:

[1]Palanichamy, A., et al.,Neutrophil-mediated IFN activation in the bone marrow alters B cell development in human and murine systemic lupus erythematosus.J Immunol, 2014.192(3): p. 906-18.

[2]Papadaki, H.A., J.C. Marsh, and G.D. Eliopoulos,Bone marrow stem cells and stromal cells in autoimmune cytopenias.Leuk Lymphoma, 2002.43(4): p. 753-60.

[3]Karrar, S. and D.S. Cunninghame Graham,Abnormal B Cell Development in Systemic Lupus Erythematosus: What the Genetics Tell Us.Arthritis Rheumatol, 2018.70(4): p. 496-507.

[4]Woods, M., Y.R. Zou, and A. Davidson,Defects in Germinal Center Selection in SLE.Front Immunol, 2015.6: p. 425.

[5]Upregulation of p16INK4A promotes cellular senescence of bone marrow-derived mesenchymal stem cells from systemic lupus erythematosus patients.Cell Signal, 2012.24(12): p. 2307-14.

Disclosure of Interests:

None declared

AB1330-HPR ASSOCIATION OF INTERSTITIAL LUNG DISEASE AND QUALITY OF LIFE IN CHINESE RHEUMATOID ARTHRITIS

Background:

The health-related quality of life (HRQL) of patients with rheumatoid arthritis associated interstitial lung disease (RA-ILD) is less concerned(1). This study hypothesized that HRQL of such patients decreased.

Objectives:

The aim of this study was to assess the difference in HRQL between RA with and without ILD, and to predict risk factors of HRQL in Chinese RA-ILD.

Methods:

A cross-sectional survey of RA-ILD patients included socio-demographic characteristics, clinical variables, psychological factors and HRQL. Data were analyzed by Student’s t or chi-square test. Linear regression analysis was used to investigate the predictors of HRQL in RA-ILD.

Results:

The data showed that 35.17% (51/145) of RA patients had ILD. There are significant differences in age, sex, smoking history, disease duration and activity between RA with and without ILD. HRQL of RA-ILD was impaired. Physical component score (PCS) of patients with RA-ILD was also worse than that of RA without ILD (48.91±2.48 vs. 50.80±2.55). Linear regression analysis showed that DAS28 and fatigue were risk factors for PCS in patients with RA-ILD, while depression and rural residence were risk factors for mental components summary in Table 1.

Table 1.

Stepwise multiple linear regression analysis of PCS and MCS in RA-ILD

PredictorsBSEtP95%CIPCSDAS28-0.7770.227-3.4250.001-1.236,-0.319Fatigue-0.6550.206-3.1770.003-1.071, -0.238MCSDepression2.1880.6693.2720.0020.836, 3.539Rural residents-1.6090.756-2.1280.040-3.137,-0.081

Footnotes: CI=Confidence interval. PCS=Physical component score; MCS=Mental component score; DAS28=28-joint disease activity score.

Conclusion:

Compared with RA without ILD, HRQL of patients with RA-ILD was significantly impaired. Disease activity, fatigue, depression and rural residence were independent predictors of HRQL in Chinese RA-ILD.

References:

[1]Zamora-Legoff JA, Krause ML, Crowson CS, Ryu JH, Matteson EL. Patterns ofinterstitial lung disease and mortality in rheumatoid arthritis. Rheumatology (Oxford, England). 2017;56(3):344-50.

Disclosure of Interests:

None declared

SAT0625-HPR FATIGUE AND CONTRIBUTING FACTORS IN CHINESE PATIENTS WITH ANKYLOSING SPONDYLITIS

Background:

Ankylosing spondylitis (AS) is a systemic chronic inflammatory disease, which most likely occurs in young men. It mainly affects sacroiliac joints, axial skeleton, thoracic cage and seriously decreasing quality of life in AS patients[1,2]. In recent years, fatigue of AS patients has been paid more and more attention[3]. Fatigue is a complex feeling, diseased individuals describe fatigue as a sense of tiredness at rest, exhaustion with activity, lack of energy which affects daily work, inertia or lack of endurance, or as loss of vitality. It has been confirmed that fatigue is not only a symptom but may also be quantified by fatigue scores and can be modified by various measures depending on the underlying cause[4]. However, there has been no study about fatigue in AS patients in China.

Objectives:

This study aimed to evaluate the predictors of fatigue and the effects of fatigue on HR-QoL among patients with AS.

Methods:

A total of 150 AS patients were involved in the study. A series of questionnaires included: Bath Ankylosing Spondylitis Disease Activity Index (BASDAI), Bath Ankylosing Spondylitis Metrology Index (BASMI), Bath Ankylosing Spondylitis Functional Index (BASFI), the 10 cm Visual Analog Scale (VAS), the Self-Rating Anxiety Scale (SAS), the Self-Rating Depression Scale (SDS), the Pittsburgh Sleep Quality Index (PSQI), the Health Assessment Questionnaire-Disability Index (HAQ-DI), the Short Form 36 Health Survey (SF-36) and the Fatigue Severity Scale(FSS). Independent samples t-test, Mann–Whitney U-test, Chi-square analysis, Pearson /Spearman correlation and binary logistic regression were used to analyze the data.

Results:

The results demonstrated that 48.7% individuals with AS suffered from fatigue. Compared with AS patients without fatigue, AS patients with fatigue showed higher WHR(P<0.05), increased BASDAI (P<0.01) and poorer BASFI (P<0.05). Meanwhile, AS patients with fatigue tended to have more severe pain(P<0.05), higher degree of anxiety(P=0.001), more serious functional disability(P=0.001) and worse sleep quality(P=0.001). Binary logistic regression indicated that WHR (OR=1.78,P<0.05), BASDAI (OR=1.34,P=0.01), sleep disturbance (OR=2.35,P<0.05) were independent predictors of fatigue in AS patients. Additionally, the occurrence of fatigue significantly reduced the quality of life in AS patients both physically and psychologically.

Conclusion:

These findings suggested that medical personnel should pay more attention to AS patients with fatigue and take effective measures to relieve fatigue.

References:

[1]Law L, Beckman Rehnman J, Deminger A, Klingberg E, Jacobsson LTH, Forsblad-d’Elia H (2018) Factors related to health-related quality of life in ankylosing spondylitis, overall and stratified by sex. Arthritis research & therapy 20 (1):284. doi:10.1186/s13075-018-1784-8

[2]Hanson A, Brown MA (2017) Genetics and the Causes of Ankylosing Spondylitis. Rheumatic diseases clinics of North America 43 (3):401-414. doi:10.1016/j.rdc.2017.04.006

[3]Ulus Y, Akyol Y, Bilgici A, Kuru O (2019) Association of work instability with fatigue and emotional status in patients with ankylosing spondylitis: comparison with healthy controls. Clinical rheumatology 38 (4):1017-1024. doi:10.1007/s10067-018-4366-x

[4]Finsterer J, Mahjoub SZ (2014) Fatigue in healthy and diseased individuals. The American journal of hospice & palliative care 31 (5):562-575. doi:10.1177/1049909113494748

Acknowledgments:

Thanks to all the authors for their efforts and thanks to all members of the Department of Rheumatology of Affiliated Hospital of Nantong University for their helpfulness in the acquisition of data.

Disclosure of Interests:

None declared

AB1329-HPR THE CURRENT STATUS AND ASSOCIATED FACTORS OF FATIGUE IN CHINESE PATIENTS WITH GOUT

Background:

Fatigue of chronic diseases has been paid more and more attention. but the status of fatigue in gout patients has not been reported all the world[1].

Objectives:

In the absence of previous studies, our study aims to investigate the fatigue status, explore the potential predictors of fatigue and the effects of fatigue on health-related quality of life (HRQoL) among Chinese gout patients.

Methods:

This cross-sectional study was conducted from the Affiliated Hospital of Nantong University. A series of questionnaires were applied: Fatigue Scale-14 (FS-14), the 10 cm visual analog scale (VAS), the Patient Health Questionnaire (PHQ-9), the Generalized Anxiety Disorder questionnaire (GAD-7), the Pittsburgh Sleep Quality Index (PSQI), Health Assessment Questionnaire(HAQ), the Short Form 36 health survey (SF-36). Laboratory examinations were taken to obtain some biochemical indicators. Independent samples t-test, Mann–Whitney U-test, Chi-square analysis, Pearson /Spearman correlation, Stepwise linear regression and binary logistic regression were used to analyze the data.

Results:

411 gout patients were included in this study. Among them, more than 50% patients reported physical fatigue in FS-14, severe disease, poor psychological status and reduced HRQoL were associated with fatigue. Multiple stepwise linear regression and binary logistic regression were applied and showed that pain, sleep quality, anxiety, depression and functional disorder were the potential predictors of fatigue. In addition, we found that the more severe the fatigue, the lower the patient’s HRQoL.

Conclusion:

Fatigue among gout patients is exceedingly common. The results of this study suggested that rheumatologists should pay closely attention to gout patients who suffer from serious fatigue, especially those with pain, poorer sleep quality, anxiety, depression and functional disorder.

References:

[1]Henry, A., Tourbah, A., Camus, G., Deschamps, R., Mailhan, L., Castex, C., Gout, O. & Montreuil, M. (2019) Anxiety and depression in patients with multiple sclerosis: The mediating effects of perceived social support, Multiple sclerosis and related disorders. 27, 46-51.

Disclosure of Interests:

None declared

AB1328-HPR INCREASED BODY MASS INDEX AFFECTS SPINAL MOBILITY RATHER THAN DISEASE ACTIVITY IN ANKYLOSING SPONDYLITIS

Background:

Studies have reported the association between overweight or obesity and ankylosing spondylitis (AS), but their relation is still unclear in China.

Objectives:

To explore the prevalence of overweight or obesity and its effect on other indicators and their relationships in Chinese AS patients.

Methods:

Demographic and clinical variables were collected from 207 AS patients. Patients were categorized to normal BMI group (BMI < 23kg/m2) and overweight group (BMI ≥ 23kg/m2). We used Bath Ankylosing Spondylitis Disease Activity Index (BASDAI), Bath Ankylosing Spondylitis Functional Index (BASFI), Bath Ankylosing Spondylitis Metrology Index (BASMI), Health Assessment Questionnaire (HAQ), Ankylosing Spondylitis Quality of Life (ASQoL) and Medical Outcomes Study Short Form 36 (SF-36) to evaluate disease activity, physical function, spinal mobility, functional limitation and health-related quality of life, respectively. Statistical analysis used independent t test, Mann-Whitney U test, Chi-square test and Spearman’s rank correlation test.

Results:

56.5% (117) AS patients were overweight or obese, among which 80.3% (94) were male. In the overweight group, patients were older, more being married, and have higher BMI, higher waist circumference, higher waist-to-hip ratio, longer disease duration, higher BASMI score, higher white blood cell count (WBC), higher lymphocyte and higher platelet count compared to the non-overweight group (P≤ 0.038). However, there was no distinct difference in BASDAI score between the two groups (P= 0.891). In the correlation analyses, gender and marital status (P≤ 0.036) were correlated negatively with BMI; while age, waist circumference, waist-to-hip ratio, WBC, lymphocyte count and red blood cell (P≤ 0.036) were correlated positively with BMI.

Conclusion:

Overweight or obesity is common in Chinese AS patients. Increased BMI affects not disease activity but spinal mobility, which indicates that patients with high BMI are more likely to have limitations in flexion, extension, lateral bending and torsion of spine.

References:

[1]Bowness P. Hla-B27. Annu Rev Immunol. 2015;33:29-48.

[2]de Araújo TA, Mota MC, Crispim CA. Obesity and sleepiness in women with fibromyalgia. Rheumatology International. 2014;35(2):281-7.

Acknowledgments:

This study was funded by Science and technology Project of Nantong City (Grant/Award Number: MSZ18217), Postgraduate Research & Practice Innovation Program of Jiangsu Province (Grant/Award number: KYCX19_2071 and KYCX18_2410), National Natural Science Foundation of China (Grant/Award number: 81671616 and 81871278), Science and technology Project of Jiangsu Province (Grant/Award number: BE2018671) and Clinical Research Center of Stem Cells, Affiliated Hospital of Nantong University, Nantong (Grant/Award number: HS2018001).

Disclosure of Interests:

None declared

THU0075 MIR-21 IN EXOSOMES DRIVED FROM DENTAL PULP STEM CELLS AMELIORATE THE TREGS/TH17 IMMUNE RESPONSE VIA TARGETING STAT3 IN COLLAGEN-INDUCED ARTHRITIS MICE

Background:

Rheumatoid arthritis (RA) is a common and systemic autoimmune disease1.It is vital for deciphering pathogenesis to define the precise CD4+Tcell subsets that are expanded or dysregulated in RA patients2.An increase in the Th17 cell subset and a decrease in Tregs resulting imbalance of Tregs/Th17 may be responsible for the occurrence and development of RA3. Dental pulp stem cells (DPSCs) appear be a new therapeutic tool for immunological diseases4,5.InRA, the mechanism of the effect of miR-21 drivedfromDPSCsexosomes (DPSCs-exo) on the balance of Tregs/Th17 is still unclear.

Objectives:

We explored the effect of exosomes drived from DPSCson RA and investigated the correlation between DPSCs-exo and Tregs/Th17 balance.

Methods:

Exosomes were isolated through differential centrifugation. Collagen-induced arthritis(CIA) mice were builded to detect histological change and Tregs/Th17 ratio.CD4+Tcells were isolated from PBMCs. Exosomes and CD4+T cells were co-cultured to study the regulation of Tregs/Th17 balance.The relationship between miR-21 and Tregs/Th17 balance was studied by flow cytometry, qRT-PCR and Western blotting etc.

Results:

After Dpscs-exo treatment, the clinical scores and paw swelling of CIA mice decreased.At the same time, the expression of Treg cells increased and the expression of Th17 cells decreased in the spleen,changing the ratio of Tregs/Th17.Exosomes and CD4+T cells were co-culture,showing that Treg cellsincreased and Th17 cellsdecreased. MiR-21 is highly expressed in RA patients.MiR-21 in exosomes were Knockout and overexpressed.The balance ofTregs/Th17 decreased when miR-21 were knockout and increased when miR-21were overexpressed. In addition, STAT3 in CD4+T cells were overexpressed and co-culture with DPSCs-exo,which inhibited Tregs/Th17.

Conclusion:

We elucidated the mechanism of the regulation of Tregs/Th17 balance by DPSCs-exo, that is, miR-21 in exosomes drived from dental pulp stem cells ameliorate the Tregs /Th17 immune response via targeting STAT3 in collagen-induced arthritis mice.

References:

[1]MF, B.et al.Hexokinase 2 as a novel selective metabolic target for rheumatoid arthritis.77, 1636-1643,doi:10.1136/annrheumdis-2018-213103 (2018).

[2]CY, F.et al.Mixed-effects association of single cells identifies an expanded effector CD4 T cell subset in rheumatoid arthritis.10,doi:10.1126/scitranslmed.aaq0305 (2018).

[3]Q, S.et al.Impaired Tip60-mediated Foxp3 acetylation attenuates regulatory T cell development in rheumatoid arthritis.100, 27-39,doi:10.1016/j.jaut.2019.02.007 (2019).

[4]L, J.et al.Comparison of immunomodulatory properties of exosomes derived from bone marrow mesenchymal stem cells and dental pulp stem cells.67, 432-442,doi:10.1007/s12026-019-09088-6 (2019).

[5]B, M., A, L., M, B., W, L. & cells, S. B. J. S. Concise Review: Dental Pulp Stem Cells: A Novel Cell Therapy for Retinal and Central Nervous System Repair.35, 61-67,doi:10.1002/stem.2398 (2017).

Disclosure of Interests: None declared

Resolvin D1 and D2 inhibit tumour growth and inflammation via modulating macrophage polarization

Plastic polarization of macrophage is involved in tumorigenesis. M1-polarized macrophage mediates rapid inflammation, entity clearance and may also cause inflammation-induced mutagenesis. M2-polarized macrophage inhibits rapid inflammation but can promote tumour aggravation. ω-3 long-chain polyunsaturated fatty acid (PUFA)-derived metabolites show a strong anti-inflammatory effect because they can skew macrophage polarization from M1 to M2. However, their role in tumour promotive M2 macrophage is still unknown. Resolvin D1 and D2 (RvD1 and RvD2) are docosahexaenoic acid (DHA)-derived docosanoids converted by 15-lipoxygenase then 5-lipoxygenase successively. We found that although dietary DHA can inhibit prostate cancer in vivo, neither DHA (10 μmol/L) nor RvD (100 nmol/L) can directly inhibit the proliferation of prostate cancer cells in vitro. Unexpectedly, in a cancer cell-macrophage co-culture system, both DHA and RvD significantly inhibited cancer cell proliferation. RvD1 and RvD2 inhibited tumour-associated macrophage (TAM or M2d) polarization. Meanwhile, RvD1 and RvD2 also exhibited anti-inflammatory effects by inhibiting LPS-interferon (IFN)-γ-induced M1 polarization as well as promoting interleukin-4 (IL-4)-mediated M2a polarization. These differential polarization processes were mediated, at least in part, by protein kinase A. These results suggest that regulation of macrophage polarization using RvDs may be a potential therapeutic approach in the management of prostate cancer.

Role of g6pdh and leuB on Lipid Accumulation in Mucor circinelloides

Mucor circinelloides is a valuable oleaginous filamentous fungus rich in γ-linolenic acid (GLA, 18:3; n-6), which is beneficial for human health. Our previous comparative proteomic analysis between high lipid-producing M. circinelloides WJ11 and low lipid-producing M. circinelloides CBS 277.49 indicated that glucose 6-phosphate dehydrogenase (G6PDH) and β-isopropylmalate dehydrogenase (IPMDH) were closely involved in lipid accumulation. Transcription analysis suggested that in the strain WJ11, g6pdh1 and g6pdh2, which encode G6PDH, and leuB, which encodes IPMDH, could be the key genes regulating lipid accumulation. To further analyze the effects of these three genes (i.e., g6pdh1, g6pdh2, and leuB) on lipid accumulation, we respectively overexpressed these genes from M. circinelloides WJ11 in defective CBS 277.49 strains in this study. The results showed that overexpression of g6pdh1 and g6pdh2 genes from strain WJ11 increased the fatty acid content of cell dry weight by 23-38 and 41-47%, respectively, compared with the control strain. Furthermore, overexpression of the leuB gene from strain WJ11 increased the fatty acid content of cell dry weight by up to 67-73%. These results suggest that g6pdh1, g6pdh2, and especially leuB genes play important roles in regulating fatty acid synthesis in M. circinelloides.

Tetrahydrobiopterin Plays a Functionally Significant Role in Lipogenesis in the Oleaginous Fungus Mortierella alpina

Tetrahydrobiopterin (BH₄) is well-known as a cofactor of phenylalanine hydroxylase (PAH) and nitric oxide synthase (NOS), but its exact role in lipogenesis is unclear. In this study, the GTP cyclohydrolase I (GTPCH) gene was overexpressed to investigate the role of BH₄ in lipogenesis in oleaginous fungus Mortierella alpina. Transcriptome data analysis reveal that GTPCH expression was upregulated when nitrogen was exhausted, resulting in lipid accumulation. Significant changes were also found in the fatty acid profile of M. alpina grown on medium that contained a GTPCH inhibitor relative to that of M. alpina grown on medium that lacked the inhibitor. GTPCH overexpression in M. alpina (the MA-GTPCH strain) led to a sevenfold increase in BH₄ levels and enhanced cell fatty acid synthesis and poly-unsaturation. Increased levels of nicotinamide adenine dinucleotide phosphate (NADPH) and upregulated expression of NADPH-producing genes in response to enhanced BH₄ levels were also observed, which indicate a novel aspect of the NADPH regulatory mechanism. Increased BH₄ levels also enhanced phenylalanine hydroxylation and nitric oxide synthesis, and the addition of an NOS or a PAH inhibitor in the MA-GTPCH and control strain cultures decreased fatty acid accumulation, NADPH production, and the transcript levels of NADPH-producing genes. Our research suggests an important role of BH₄ in lipogenesis and that the phenylalanine catabolism and arginine-nitric oxide pathways play an integrating role in translating the effects of BH₄ on lipogenesis by regulating the cellular NADPH pool. Thus, our findings provide novel insights into the mechanisms of efficient lipid biosynthesis regulation in oleaginous microorganisms and lay a foundation for the genetic engineering of these organisms to optimize their dietary fat yield.

Dietary Supplementation of n-3 LCPUFAs Prevents Salmonellosis in a Murine Model

Salmonellosis is a world-wide epidemic, and n-3 long chain polyunsaturated fatty acids (LCPUFAs) possess various health benefits. This study is aimed to investigate the preventive effects of n-3 LCPUFAs against Salmonella infection. By pretreatment with n-3 LCPUFAs, but not n-6 LCPUFAs, the survival rate of the infected mice was increased. Further studies showed that n-3 LCPUFAs significantly increased the fecal contents of short-chain fatty acids (SCFAs). The cytokine expression in the liver and production in serum were both modulated by n-3 LCPUFAs into an anti-inflammatory profile against infection. Moreover, the changes in gut microbiota by n-3 LCPUFAs favored the host against pathogens, closely related to the modified SCFA production and immune responses. In conclusion, n-3 LCPUFAs prevented Salmonella infection through multiple mechanisms, especially by the interaction with gut microbiota and host immunology. Our results suggested great perspectives for n-3 LCPUFAs and their related products to control the prevalence of Salmonella, a most predominant food-borne pathogen.

An electro-osmotic microfluidic system to characterize cancer cell migration under confinement

We have developed a novel electro-osmotic microfluidic system to apply precisely controlled osmolarity gradients to cancer cells in micro-channels. We observed that albeit adhesion is not required for cells to migrate in such a confined microenvironment, the migrating velocity of cells is strongly influenced by the interactions between the cells and the channel wall, with a stronger adhesion leading to diminished cell motility. Furthermore, through examining more than 20 different types of cancer cells, we found a linear positive correlation between the protein concentration of the aquaporin-4 (AQP4) and the cell migrating speed. Knockdown of AQP4 in invasive re-populated cancer stem cells reduced their migration capability down to the level that is comparable to their parental cancer cells. Interestingly, these observations can all be quantitatively explained by the osmotic engine model where the cell movement is assumed to be driven by cross-membrane ion/water transport, while adhesion acts as a frictional resistance against the cell motility. By providing versatile and controllable features in regulating and characterizing the migration capability of cells, our system may serve as a useful tool in quantifying how cell motility is influenced by different physical and biochemical factors, as well as elucidating the mechanisms behind, in the future.

Structural Determinants of Substrate Specificity of Omega-3 Desaturases from Mortierella alpina and Rhizophagus irregularis by Domain-Swapping and Molecular Docking

Although various ω-3 fatty acid desaturases (ω3Des) have been identified and well-studied regarding substrate preference and regiospecificity, the molecular mechanism of their substrate specificities remains to be investigated. Here we compared two ω3Des, FADS15 from Mortierella alpina and oRiFADS17 from Rhizophagus irregularis, which possessed a substrate preference for linoleic acid and arachidonic acid, respectively. Their sequences were divided into six sections and a domain-swapping strategy was used to test the role of each section in catalytic activity. Heterologous expression and fatty acid experiments of hybrid enzymes in Saccharomyces cerevisiae INVSc1 indicated that the sequences between his-boxes I and II played critical roles in influencing substrate preference. Based on site-directed mutagenesis and molecular docking, the amino acid substitutions W129T and T144W, located in the upper part of the hydrocarbon chain, were found to be involved in substrate specificity, while V137T and V152T were confirmed to interfere with substrate recognition. This study provides significant insight into the structure-function relationship of ω3Des.

Lactobacillus plantarum ZS2058 and Lactobacillus rhamnosus GG Use Different Mechanisms to Prevent Salmonella Infection in vivo

Pathogen-induced infectious diseases pose great threats to public health. Accordingly, many studies have investigated effective strategies targeting pathogenic infections. We previously reported the preventive effects of Lactobacillus plantarum ZS2058 (ZS2058) and L. rhamnosus GG (LGG) against Salmonella spp. in a murine model. Here, we compared the mechanisms underlying the preventive effects of these Lactobacillus strains in vivo. Notably, reduced C-reactive protein levels were observed with both ZS2058 and LGG, which suggests abrogated anti-infection and inflammatory responses. ZS2058 more efficiently reduced the pathogenicity of Salmonella by increasing the level of propionic acid in feces and production of mucin 2 in the mouse colon and activity through the interleukin (IL)-23/IL-22 and IL-23/IL-17 pathways. Meanwhile, LGG more strongly alleviated gut inflammation, as indicated by changes in the levels of tissue necrosis factor (TNF)-α, IL-10 and myeloperoxidase (MPO) in infected mice. Moreover, both ZS2058 and LGG restored the levels of interferon (INF)-γ, a cytokine suppressed by Salmonella, albeit through different pathways. Our results demonstrate that ZS2058 and LGG prevent Salmonella infection via different mechanisms.

Expression of miR-33 from an SREBP2 intron inhibits the expression of the fatty acid oxidation-regulatory genes CROT and HADHB in chicken liver

1. Limiting the growth of adipose tissue in chickens is a major issue in the poultry industry. In chickens, de novo synthesis of lipids occurs primarily in the liver. Thus, it is necessary to understand how fatty acid accumulation in the liver is controlled. The miR-33 is an intronic microRNA (miRNA) of the chicken sterol regulatory element binding transcription factor 2 (SREBF2), which is a master switch in activating many genes involved in the uptake and synthesis of cholesterol, triglycerides, fatty acids and phospholipids. 2. In the current study, the genes CROT and HADHB known to encode enzymes critical for fatty acid oxidation were predicted to be potential targets of miR-33 in chickens via the miRNA target prediction programs 'miRanda' and 'TargetScan'. Co-transfection and dual-luciferase reporter assays showed that the expression of luciferase reporter gene linked to the 3'-untranslated region (3'UTR) of the chicken CROT and HADHB mRNA was down-regulated by overexpression of the chicken miR-33 (P < 0.05). This down-regulation was completely abolished when the predicted miR-33 target sites in the CROT and HADHB 3'UTR were mutated. 3. Transfecting miR-33 mimics into the LMH cells led to a decrease in the mRNA expression of CROT and HADHB (P < 0.01), and this transfection had a similar effect on the proteins (P < 0.05). In contrast, the expression of CROT in primary chicken hepatocytes was up-regulated after transfection with the miR-33 inhibitor LNA-anti-miR-33 (P < 0.05). 4. Using quantitative RT-PCR, it was shown that the expression of miR-33 was increased in the chicken liver from day 0 to day 49 of age, whereas the CROT and HADHB mRNA levels decreased during the same period. 5. These findings support the conclusion that miR-33 might play an important role in lipid metabolism in the chicken liver by negatively regulating the expression of the CROT and HADHB genes, which encode enzymes critical for lipid oxidation.

Characterization and molecular docking of new Δ17 fatty acid desaturase genes from Rhizophagus irregularis and Octopus bimaculoides

Fatty acid desaturases are key enzymes in the biosynthesis of n-3 polyunsaturated fatty acids (PUFAs) via conversion of n-6 polyunsaturates to their n-3 counterparts.