Kuang-Yung Huang

Decreased microRNA(miR)-145 and increased miR-224 expression in T cells from patients with systemic lupus erythematosus involved in lupus immunopathogenesis

Systemic lupus erythematosus (SLE) is a systemic autoimmune disease with abnormal T cell immune responses. We hypothesized that aberrant expression of microRNAs (miRNAs) in T cells may contribute to the pathogenesis of SLE. First, we analysed the expression profiles of 270 human miRNAs in T cells from five SLE patients and five healthy controls and then validated those potentially aberrant‐expressed miRNAs using real‐time polymerase chain reaction (PCR). Then, the expression of mRNAs regulated by these aberrant‐expressed miRNAs was detected using real‐time PCR. Finally, miRNA transfection into Jurkat T cells was conducted for confirming further the biological functions of these miRNAs. The initial analysis indicated that seven miRNAs, including miR‐145, miR‐224, miR‐513‐5p, miR‐150, miR‐516a‐5p, miR‐483‐5p and miR‐629, were found to be potentially abnormally expressed in SLE T cells. After validation, under‐expressed miR‐145 and over‐expressed miR‐224 were noted. We further found that STAT1 mRNA targeted by miR‐145 was over‐expressed and apoptosis inhibitory protein 5 (API5) mRNA targeted by miR‐224 was under‐expressed in SLE T cells. Transfection of Jurkat cells with miR‐145 suppressed STAT1 and miR‐224 transfection suppressed API5 protein expression. Over‐expression of miR‐224 facilitates activation‐induced cell death in Jurkat cells. In the clinical setting, the increased transcript levels of STAT1 were associated significantly with lupus nephritis. In conclusion, we first demonstrated that miR‐145 and miR‐224 were expressed aberrantly in SLE T cells that modulated the protein expression of their target genes, STAT1 and API5, respectively. These miRNA aberrations accelerated T cell activation‐induced cell death by suppressing API5 expression and associated with lupus nephritis by enhancing signal transducer and activator of transcription‐1 (STAT)‐1 expression in patients with SLE.

The Combined Effect of Individual and Neighborhood Socioeconomic Status on Cancer Survival Rates

Background This population-based study investigated the relationship between individual and neighborhood socioeconomic status (SES) and mortality rates for major cancers in Taiwan. Methods A population-based follow-up study was conducted with 20,488 cancer patients diagnosed in 2002. Each patient was traced to death or for 5 years. The individual income-related insurance payment amount was used as a proxy measure of individual SES for patients. Neighborhood SES was defined by income, and neighborhoods were grouped as living in advantaged or disadvantaged areas. The Cox proportional hazards model was used to compare the death-free survival rates between the different SES groups after adjusting for possible confounding and risk factors. Results After adjusting for patient characteristics (age, gender, Charlson Comorbidity Index Score, urbanization, and area of residence), tumor extent, treatment modalities (operation and adjuvant therapy), and hospital characteristics (ownership and teaching level), colorectal cancer, and head and neck cancer patients under 65 years old with low individual SES in disadvantaged neighborhoods conferred a 1.5 to 2-fold higher risk of mortality, compared with patients with high individual SES in advantaged neighborhoods. A cross-level interaction effect was found in lung cancer and breast cancer. Lung cancer and breast cancer patients less than 65 years old with low SES in advantaged neighborhoods carried the highest risk of mortality. Prostate cancer patients aged 65 and above with low SES in disadvantaged neighborhoods incurred the highest risk of mortality. There was no association between SES and mortality for cervical cancer and pancreatic cancer. Conclusions Our findings indicate that cancer patients with low individual SES have the highest risk of mortality even under a universal health-care system. Public health strategies and welfare policies must continue to focus on this vulnerable group.

Low socioeconomic status increases short-term mortality of acute myocardial infarction despite universal health coverage

BACKGROUND This nationwide population-based study investigated the relationship between individual and neighborhood socioeconomic status (SES) and mortality rates for acute myocardial infarction (AMI) in Taiwan. METHODS A population-based follow-up study included 23,568 patients diagnosed with AMI from 2004 to 2008. Each patient was monitored for 2 years, or until their death, whichever came first. The individual income-related insurance payment amount was used as a proxy measure of patients individual SES. Neighborhood SES was defined by household income, and neighborhoods were grouped as advantaged or disadvantaged. The Cox proportional hazards model was used to compare the mortality rates between the different SES groups after adjusting for possible confounding risk factors. RESULTS After adjusting for potential confounding factors, AMI patients with low individual SES had an increased risk of death than those with high individual SES who resided in advantaged neighborhoods. In contrast, the cumulative readmission rate from major adverse cardiovascular events did not differ significantly between the different individual and neighborhood SES groups. AMI patients with low individual SES had a lower rate of diagnostic angiography and subsequent percutaneous coronary intervention (P<0.001). The presence of congestive heart failure, chronic kidney disease, chronic obstructive pulmonary disease, pneumonia, septicemia, and shock revealed an incremental increase with worse SES (P<0.001). CONCLUSIONS The findings indicate that AMI patients with low individual SES have the greatest risk of short-term mortality despite being under a universal health-care system. Public health strategies and welfare policies must continue to focus on this vulnerable group.

Multivariate analyses to assess the effects of surgeon and hospital volume on cancer survival rates: a nationwide population-based study in Taiwan.

Background Positive results between caseloads and outcomes have been validated in several procedures and cancer treatments. However, there is limited information available on the combined effects of surgeon and hospital caseloads. We used nationwide population-based data to explore the association between surgeon and hospital caseloads and survival rates for major cancers. Methodology A total of 11677 patients with incident cancer diagnosed in 2002 were identified from the Taiwan National Health Insurance Research Database. Survival analysis, the Cox proportional hazards model, and propensity scores were used to assess the relationship between 5-year survival rates and different caseload combinations. Results Based on the Cox proportional hazard model, cancer patients treated by low-volume surgeons in low-volume hospitals had poorer survival rates, and hazard ratios ranged from 1.3 in head and neck cancer to 1.8 in lung cancer after adjusting for patients’ demographic variables, co-morbidities, and treatment modality. When analyzed using the propensity scores, the adjusted 5-year survival rates were poorer for patients treated by low-volume surgeons in low-volume hospitals, compared to those treated by high-volume surgeons in high-volume hospitals (P<0.005). Conclusions After adjusting for differences in the case mix, cancer patients treated by low-volume surgeons in low-volume hospitals had poorer 5-year survival rates. Payers may implement quality care improvement in low-volume surgeons.

Higher LPS-stimulated TNF-α mRNA levels in peripheral blood mononuclear cells from Chinese ankylosing spondylitis patients with −308G/A polymorphism in promoter region of tumor necrosis factor: association with distinct A33/B58/Cw10 haplotypes

To investigate the effects of TNF-α −308, −238 promoter polymorphisms on TNF-α transcription in B27 positive Chinese patients with ankylosing spondylitis (AS). The possible relationship between polymorphisms, MHC antigens, and quantitative TNF-α mRNA expression were evaluated. Single nucleotide polymorphisms (SNPS) of TNF-α −308 and −238 were performed by PCR-amplification refractory mutation system method (PCR-ARMS) in sixty-seven B27-positive AS patients and 60 HLA-B27 positive healthy controls in Chinese. Quantitative measurement of TNF-α mRNA in peripheral blood mononuclear cells was performed with real time RT-PCR. The polymorphisms were correlated to quantitative TNF-α mRNA, and MHC antigens (determined by SSP method) in AS patients. The prevalence rate of both −308G/A and −238G/A TNF-α promoter polymorphisms in patients were not significantly different from those in normal subjects. However, a significant high LPS-stimulated TNF-α mRNA expression was found in peripheral blood mononuclear cells from patients with promoter −308G/A polymorphism (TNF2) as compared to those in −308G/G genotype (TNF1). Furthermore, −308G/A polymorphism in patients was found to be tightly associated with distinct haplotypes of A33/B58/Cw10 [12 out of 14 –308G/A patients (85.7%) versus none in 53 –308G/G patients], independent of B27 antigen. HLA-A33-B58-Cw10 haplotypes associated TNF-α promoter −308G/A polymorphism might play an important role in disease pathogenesis of AS in Chinese population, partially related to a driving force of a higher TNF-α production. It confirms once again the importance and complexity of MHC related molecules in disease pathogenesis of AS.

Differential Impact of Statin on New-Onset Diabetes in Different Age Groups: A Population-Based Case-Control Study in Women from an Asian Country

Background Statins reduce cardiovascular risks but increase the risk of new-onset diabetes (NOD). The aim of this study is to determine what effect, if any, statins have on the risk of NOD events in a population-based case-control study. An evaluation of the relationship between age and statin-exposure on NOD risks was further examined in a female Asian population. Method In a nationwide case-controlled study, the authors assessed 1065 female NOD patients and 10650 controls with matching ages, genders and physician visit dates. The impact of statin-exposure on NOD was examined through multiple logistic regression models. Subgroup analysis for exploring the risk of NOD and statin-exposure in different age groups was performed. Results Statin-exposure was statistically significantly associated with increased new-onset diabetes risks using multivariate analysis. Interaction effect between age and statin-exposure on NOD risk was noted. For atorvastatin, the risk of cDDDs>60 was highest among the 55–64 year-olds (adjusted odds ratio [OR], 8.0; 95% confidence interval [CI], 2.57–24.90). For rosuvastatin, the risk of cDDDs>60 was highest among the 40–54 year-olds (adjusted OR, 14.8; 95% CI, 2.27–96.15). For simvastatin, the risk of cDDDs>60 was highest among the 55–64 year-olds (adjusted OR, 15.8; 95% CI, 5.77–43.26). For pravastatin, the risk of cDDDs>60 was highest among the 55–64 year-olds (adjusted OR, 14.0; 95% CI, 1.56–125.18). Conclusions This population-based study found that statin use is associated with an increased risk of NOD in women. The risk of statin-related NOD was more evident for women aged 40–64 years compared to women aged 65 or more, and was cumulative-dose dependent. The use of statins should always be determined by weighing the clinical benefits and potential risks for NOD, and the patients should be continuously monitored for adverse effects.

Pneumococcal Pneumonia and the Risk of Stroke: A Population-Based Follow-Up Study

Background To investigate the risk of developing stroke in patients hospitalized following a diagnosis of pneumococcal pneumonia. Methods The study cohorts comprised of patients hospitalized with a principal diagnosis of pneumococcal pneumonia (n  = 745), with a random sampling of control individuals in 2004 (n  = 1490). The Cox proportional hazard model was used to compare the stroke-free survival rate between the cohorts after adjusting for possible confounding and risk factors for a two-year follow up. Instrumental variable analysis (IVA) was used to address potential biases associated with measured and unmeasured confounding variables. Results Of the 153 patients with stroke, 80 (10.7%) were from the pneumococcal pneumonia cohort, and 73 (4.9%) were from the control group. The risk of stroke was 3.65 times higher (95% confidence interval, 2.25–5.90; P<0.001) in patients with pneumococcal pneumonia after adjusting for patient characteristics, co-morbidities, geographic region, urbanization level of residence, and socioeconomic status during the first year. IVA showed an additional 14% risk of stroke for pneumococcal pneumonia patients (odds ratio = 1.14; 95% CI, 1.02–1.26, P = 0.032). Conclusions Patients with pneumococcal pneumonia carry an increased risk for stroke than the general population. Further studies are warranted for developing better diagnostic and follow-up strategies for patients with increased risk.

Phostensin caps to the pointed end of actin filaments and modulates actin dynamics.

Phostensin, a protein phosphatase 1 F-actin cytoskeleton targeting subunit encoded by KIAA1949, consists of 165 amino acids and is located between HLA-C and HLA-E gene clusters on human chromosome 6. In this current study, we characterized the biochemical functions of phostensin. Actin dynamics assays using gelsolin-actin seeds showed that phostensin decreases the elongation and depolymerization rates of actin filament pointed ends. The feature of phostensin that binds to the pointed ends of actin filaments was observed through fluorescent single filament binding assay. Taken together, our results suggested that phostensin is an actin filament pointed end-capping protein that is capable of modulating actin dynamics.

Anti-citrullinated protein antibodies activated ERK1/2 and JNK mitogen-activated protein kinases via binding to surface-expressed citrullinated GRP78 on mononuclear cells.

In a previous study, we found that anti-citrullinated protein antibodies (ACPAs) enhance nuclear factor (NF)-κB activity and tumor necrosis factor (TNF)-α production by normal human peripheral blood mononuclear cells (PBMCs) and U937 cells via binding to surface-expressed citrullinated glucose-regulated protein 78 (cit-GRP78). However, the downstream signaling pathways remain unclear after binding. In the present study, we firstly measured the effects of different kinase inhibitors on ACPA-mediated TNF-α production from normal PBMCs and monocytes. Then, the native and phosphorylated mitogen-activated protein kinases (MAPKs) were detected in ACPA-activated U937 cells by Western blotting. We also explored the role of the phosphoinositide 3-kinase (PI3K)-Akt pathway in activating IκB kinase alpha (IKK-α) in ACPA-stimulated U937 cells. Finally, we measured the amount of cit-GRP78 from PBMC membrane extracts in RA patients and controls. We found that MAPK and Akt inhibitors, but not PI3K inhibitor, remarkably suppressed ACPA-mediated TNF-α production. Interestingly, ACPAs selectively activated extracellular signal-regulated kinase 1/2 (ERK1/2) and c-jun N-terminal kinase (JNK), but not p38 MAPK, in U937 cells. This activation was suppressed by cit-GRP78, but not GRP78. The JNK activation further enhanced the phosphorylation of Akt and IKK-α. The expression of cit-GRP78 on cell membrane was higher in RA than normal PBMCs. Taken together; these results suggest that through binding to surface, over-expressed cit-GRP78 on RA PBMCs, ACPAs selectively activate ERK1/2 and JNK signaling pathways to enhance IKK-α phosphorylation, which leads to the activation of NF-κB and the production of TNF-α .

Increased prevalence of polyomavirus BK viruria that correlates with thrombocytopenia in patients with systemic lupus erythematosus on intensive immunosuppressive therapy

The prevalence of polyomavirus BK (BKV) reactivation is high in patients with systemic lupus erythematosus (SLE) on long-term immunosuppressants compared to normal population. However, only a few studies are available for the possible correlation of BKV reactivation and clinical manifestations in SLE patients. In the present study, we tried to correlate BKV viruria, clinical manifestations, laboratory findings, and medications in patients with SLE. The urine BKV viral DNA copies were detected from 95 patients with SLE and 32 healthy volunteers by real-time PCR. We found that the prevalence rate of BKV viruria in SLE patients was significantly higher than normal group (71.6% vs. 18.6%, p < 0.001) as well as the urine BKV DNA viral load (4.74 ± 3.17 vs. 1.08 ± 2.33 by log scale, p < 0.001). Interestingly, BKV viruria (+) SLE patients had more thrombocytopenic events than BKV viruria ( − ) group (32.4% vs. 3.7%, p = 0.008 after adjustment by age and sex). The patients with BKV viruria DNA copy number >3,200,000/ml exhibited more thrombocytopenia risk than BKV viruria ≦3,200,000 copy number/ml or BKV viruria ( − ). The use of potent immunosuppressants may increase BKV viruria. In a refractory thrombocytoponeic case, the add-on of anti-BKV medication, leflunomide 20 mg/day rapidly decreased BKV viruria and recovered platelet counts. In conclusion, our study demonstrated that patients with SLE had higher prevalence rate of BKV reactivation that is correlated with thrombocytopenic episode. Intensive immunosuppressive therapy in SLE may increase the risk of BKV viruria.