Chih-Yuan Wang

Motility and Protein Phosphorylation in Healthy and Asthenozoospermic Sperm

The majority of male infertility results from poor sperm motility. A direct link between altered protein phosphorylation and aberrant sperm motility has not been established. To address this issue, sperm samples obtained from 20 donors with healthy sperm and 20 donors with aberrantly motile sperm were subjected to computer assisted semen analysis (CASA), proteomic analysis, Western blot, and immunofluorescent staining. Proteomic analysis identified 12 protein spots as having differential phosphorylation, including gamma-tubulin complex associated protein 2 (GCP2). Western blot and immunofluorescence demonstrated differential expression of gamma-tubulin between healthy and aberrantly motile sperm. In conclusion, hypophosphorylated proteins and reduced expression of gamma-tubulin may be associated with low motility sperm.

The Association between Nonalcoholic Fatty Pancreas Disease and Diabetes

Background Fatty infiltration of the pancreas has been shown to interfere with insulin secretion. Both insulin sensitivity and secretion are important in the pathogenesis of diabetes and prediabetes. However, the relationship between diabetes, prediabetes, and fatty pancreas remains unknown. We aim to investigate the relationships that fatty pancreas and nonalcoholic fatty liver disease (NAFLD) have with prediabetes and diabetes in a Chinese population. Patients and Methods This was a cross-sectional study. A total of 7,464 subjects were recruited. NAFLD and fatty pancreas were assessed by sonography. Clinico-metabolic parameters were compared among subjects with normoglycemia, prediabetes, and diabetes. Multinomial logistic regression was used to evaluate the relationship between fatty pancreas and NAFLD and diabetes or prediabetes with adjustment for cardiometabolic risk factors. Results With an increase in glycemia, a significantly greater proportion of subjects had NAFLD and fatty pancreas (test for trend p<0.05). Similar trends were also found for hypertension, general and central obesity, low-HDL cholesterol, and hypertriglyceridemia. In the logistic regression analysis, age, hypertension, male gender, hypertriglyceridemia, and central obesity were significantly associated with prediabetes and diabetes. Furthermore, the ORs of prediabetes and diabetes for NAFLD were 1.798 (95% CI 1.544–2.094) and 2.578 (95% CI 2.024–3.284), respectively. In addition, fatty pancreas was independently related to diabetes (OR, 1.379; 95% CI, 1.047–1.816) and prediabetes (OR, 1.222; 95% CI, 1.002–1.491) in male subjects. Conclusions Both NAFLD and fatty pancreas were associated with diabetes independent of age, gender, adiposity, and other cardiometabolic risk factors. Fatty pancreas was also related to prediabetes in males.

Enigmatic Ectopic Fat: Prevalence of Nonalcoholic Fatty Pancreas Disease and Its Associated Factors in a Chinese Population

Background Fatty infiltration of the pancreas is an enigmatic manifestation of ectopic fat deposition in obesity. Studies have shown that pancreatic lipid accumulation interferes with insulin secretion in humans. However, the prevalence of fatty pancreas and its associated factors in the general population remain unclear. The aim of this study was to investigate the prevalence of fatty pancreas and its association with diabetes, nonalcoholic fatty liver disease (NAFLD), and cardiometabolic risk factors in a Chinese population. Methods and Results This was a cross‐sectional study. A total of 8097 subjects with or without fatty pancreas (n=1297 and 6800, respectively) were recruited. Each subject was assessed by using abdominal sonography to diagnose NAFLD and fatty pancreas. Clinical and metabolic parameters were compared between groups, and their associations with fatty pancreas were examined. The prevalence of fatty pancreas was 16%. The fatty pancreas group had a significantly greater proportion of subjects with diabetes (12.6% versus 5.2%) and NAFLD (67.2% versus 35.1%) than did the non–fatty pancreas group (P<0.001). In the logistic regression analysis, age (P<0.001), general or central obesity (P<0.001), diabetes (P<0.001), and NAFLD (P<0.001) were independently associated with fatty pancreas after adjustment for sex, lipid profile, alanine transaminase/aspartate transaminase ratio, hypertension, smoking, alcohol drinking, and exercise. Conclusions The prevalence of fatty pancreas is high in the general population. Both diabetes and NAFLD are important associated factors of fatty pancreas, independent of age, sex, adiposity, and other cardiometabolic risk factors.

Association between non-alcoholic fatty pancreatic disease (nafpd) and the metabolic syndrome: case–control retrospective study

BackgroundFatty liver is associated with insulin resistance, dyslipidemia, and obesity and is therefore considered a phenotype of metabolic syndrome. However, less is known regarding the metabolic abnormalities associated with non-alcoholic fatty pancreatic disease (NAFPD; fatty pancreas). The present study was performed to ascertain whether fatty pancreas is associated with specific metabolic risk factors and with metabolic syndrome as defined by the Adult Treatment Panel III.MethodsFive-hundred-fifty-seven healthy and consecutive subjects without known hypertension or diabetes and who received a health investigation at the National Taiwan University Hospital Health Management Center were enrolled in this retrospective study. Fatty pancreas was diagnosed via trans-abdominal ultrasonographic findings.ResultsSeventy-two (12.9%) subjects diagnosed with fatty pancreas comprised the fatty pancreas group, and remaining subjects comprised the normal pancreas group. The presence of various demographic and metabolic risk factors was recorded for all subjects, and the two groups were examined for statistically significant differences in these factors. As compared to the absence of fatty pancreas, the presence of the disease was associated with older age and with higher values for each of the following: BMI, abdominal girth/height, abdominal girth (both genders), fasting and postprandial blood glucose, HbA1c, total cholesterol, triglycerides, LDL-cholesterol, systolic blood pressure, and platelet count. In contrast to previously reported findings, serum amylase values were lower in the fatty pancreas as compared to the control group.ConclusionThe presence of fatty pancreas represents a meaningful manifestation of metabolic syndrome together with obesity.

2017 Taiwan lipid guidelines for high risk patients

In Taiwan, the prevalence of hyperlipidemia increased due to lifestyle and dietary habit changes. Low density lipoprotein cholesterol (LDL-C) and non-high density lipoprotein cholesterol (non-HDL-C) are all significant predicting factors of coronary artery disease in Taiwan. We recognized that lipid control is especially important in patients with existed atherosclerotic cardiovascular diseases (ASCVD), including coronary artery disease (CAD), ischemic stroke and peripheral arterial disease (PAD). Because the risk of ASCVD is high in patients with diabetes mellitus (DM), chronic kidney disease (CKD) and familial hypercholesterolemia (FH), lipid control is also necessary in these patients. Lifestyle modification is the first step to control lipid. Weight reduction, regular physical exercise and limitation of alcohol intake all reduce triglyceride (TG) levels. Lipid-lowering drugs include HMG-CoA reductase inhibitors (statins), cholesterol absorption inhibitors (ezetimibe), proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors, nicotinic acids (niacin), fibric acids derivatives (fibrates), and long-chain omega-3 fatty acids. Statin is usually the first line therapy. Combination therapy with statin and other lipid-lowering agents may be considered in some clinical settings. For patients with acute coronary syndrome (ACS) and stable CAD, LDL-C < 70 mg/dL is the major target. A lower target of LDL-C <55 mg/dL can be considered in ACS patients with DM. After treating LDL-C to target, non-HDL-C can be considered as a secondary target for patients with TG ≥ 200 mg/dL. The suggested non-HDL-C target is < 100 mg/dL in ACS and CAD patients. For patients with ischemic stroke or transient ischemic attack presumed to be of atherosclerotic origin, statin therapy is beneficial and LDL-C < 100 mg/dL is the suggested target. For patients with symptomatic carotid stenosis or intracranial arterial stenosis, in addition to antiplatelets and blood pressure control, LDL-C should be lowered to < 100 mg/dL. Statin is necessary for DM patients with CV disease and the LDL-C target is < 70 mg/dL. For diabetic patients who are ≥ 40 years of age, or who are < 40 years of age but have additional CV risk factors, the LDL-C target should be < 100 mg/dL. After achieving LDL-C target, combination of other lipid-lowering agents with statin is reasonable to attain TG < 150 mg/dL and HDL-C >40 in men and >50 mg/dL in women in DM. LDL-C increased CV risk in patients with CKD. In adults with glomerular filtration rate (GFR) < 60 mL/min/1.73m2 without chronic dialysis (CKD stage 3-5), statin therapy should be initiated if LDL-C ≥ 100 mg/dL. Ezetimibe can be added to statin to consolidate the CV protection in CKD patients. Mutations in LDL receptor, apolipoprotein B and PCSK9 genes are the common causes of FH. Diagnosis of FH usually depends on family history, clinical history of premature CAD, physical findings of xanthoma or corneal arcus and high levels of LDL-C. In addition to conventional lipid lowering therapies, adjunctive treatment with mipomersen, lomitapide, or PCSK9 inhibitors become necessary to further reduce LDL-C in patients with FH. Overall, these recommendations are to help the health care professionals in Taiwan to treat hyperlipidemia with current scientific evidences. We hope the prescription rate of lipid lowering drugs and control rate of hyperlipidemia in high risk patients could be increased by implementation of the clinical guidelines. The major purpose is to improve clinical outcomes of these high risk patients through the control of hyperlipidemia.

Proteomic analysis and identification of aqueous humor proteins with a pathophysiological role in diabetic retinopathy.

Diabetic retinopathy (DR) can cause irreversible blindness and is the severest microvascular complication in the eyes of patients with diabetic mellitus (DM). The identification of susceptibility factors contributing to development of DR is helpful for identifying predisposed patients and improving treatment efficacy. Although proteomics analysis is useful for identifying protein markers related to diseases, it has never been used to explore DR-associated susceptibility factors in the aqueous humor (AH). To better understand the pathophysiology of DR and to identify DR-associated risk factors, a gel-based proteomics analysis was performed to compare AH protein profiles of DM patients with and without development of DR. MALDI-TOF MS was then performed to identify protein spots that were differentially expressed between the two groups and western blot analysis was used to validate the expressional change of protein demonstrated by proteomics. Our proteomics and bioinformatics analysis identified 11 proteins differentially expressed between DR and control groups. These proteins are linked to biological networks associated with nutrition transport, microstructure reorganization, angiogenesis, anti-oxidation, and neuroprotection. The data may provide potential AH biomarkers and susceptibility factors for predicting DR development, and provide an insight into the underlying pathophysiological mechanisms of DR. This article is part of a Special Issue entitled: Proteomics: The clinical link.

Magnolol induces apoptosis in human leukemia cells via cytochrome c release and caspase activation.

Magnolol, isolated from the stem bark of Magnolia officnalis, was found to inhibit proliferation of human HL-60 cells and Jurkat T leukemia cells via inducing apoptosis in a dose- and time-dependent manner. By contrast, magnolol did not cause apoptosis in neutrophils and peripheral blood mononuclear cells of healthy donors. Apoptosis was determined by detection of DNA fragmentation in gel electrophoresis, morphological alternations by flow cytometry, quantification of phosphatidylserine externalization by Annexin V labeling and oligonucleosomal DNA content by TUNEL labeling. Activation of caspase-9, -3 and -2, and the proteolytic cleavage of poly(ADP-ribose) polymerase were found during apoptosis induced by magnolol. In addition, both pan-caspase and selective caspase-9 inhibitor blocked magnolol-induced apoptosis. The apoptosis could also be partially attenuated by caspase-3 and -2 inhibitors. Magnolol induced the reduction of mitochondrial transmembrane potential and the release of cytochrome c into cytoplasm. In conclusion, our findings indicate that magnolol-induced apoptotic signaling is carried out through mitochondria alternations to caspase-9 and that then the downstream effector caspases are activated sequentially. Magnolol could be a potentially effective drug for leukemia with low toxicity to normal blood cells and it merits further investigation.

In vivo evidence of duality effects for lovastatin in a nude mouse cancer model

Statins, hydroxy‐methyl‐glutaryl coenzyme A reductase inhibitors, are the most effective medication for lowering cholesterol, cardiovascular morbidity and mortality. On the basis of our previous in vitro experimental results on an anaplastic thyroid cancer cell line, we designed a nude mouse model in which cancer cells were seeded subcutaneously to examine the potential anticancer effects of lovastatin in vivo. As expected, tumor growth was significantly reduced in the mice treated with 5 or 10 mg/kg/day of lovastatin compared with the positive control group. However, the tumor grew much faster in the mice treated with 1 mg/kg/day of lovastatin than in the positive control group. We suspect this result might be related to vascular endothelial growth factor. In this model, we found that lovastatin inhibits tumor growth at a high dosage (5 or 10 mg/kg/day), suggesting it could be used as an effectively adjuvant chemotherapy for cancer. However, it also promotes tumor growth at a low dosage (1 mg/kg/day). This duality effect should be further studied for patients treated with various dosages of statins.

Morphological and molecular studies of a microsporidium (Nosema sp.) isolated from the thee spot grass yellow butterfly, Eurema blanda arsakia (Lepidoptera: Pieridae).

A microsporidium possessing molecular and morphological characteristics of the genus Nosema was isolated from larvae of the thee-spot grass yellow butterfly, Eurema blanda arsakia. The complete rRNA gene sequences of the E. blanda isolate contained 4,428 base pairs (GenBank Accession No. EU338534). The organization of the rRNA genes is LSU rRNA-ITS-SSU rRNA-IGS-5S, which corresponds with that of Nosema species closely related to Nosema bombycis. Phylogenetic analysis based on rRNA gene sequences show that this isolate is closely related to Nosema bombycis, Nosema plutellae, Nosema spodopterae, and Nosema antheraeae. The ultrastructure of all developmental stages of this microsporidium confirmed its placement in the genus Nosema. The isolate was successfully propagated in cell lines IPLB-LD652Y (Lymantria dispar) and NTU-LY (Lymantria xylina) and, in the in vitro system, it was frequently found to develop in the nuclei of the host cells, a circumstance that seldom occurs in other Nosema species. An extra-cellular vegetative stage of this microsporidium was also observed in the culture medium after 14 days of infection. The ECMDFs might be released from disrupted host cells.

Prediabetes Is Associated with an Increased Risk of Testosterone Deficiency, Independent of Obesity and Metabolic Syndrome

Objective The association between type 2 diabetes and low testosterone has been well recognized. However, testosterone levels in men with prediabetes have been rarely reported. We aimed to investigate whether prediabetes was associated with an increased risk of testosterone deficiency. Methods This study included 1,306 men whose sex hormones was measured during a medical examination. Serum total testosterone and sex hormone-binding globulin were measured; free and bioavailable testosterone concentrations were calculated by Vermeulen’s formula. Prediabetes was defined by impaired fasting glucose (IFG), impaired postprandial glucose (IPG), or glycated hemoglobin (HbA1c) 5.7%-6.4%. Logistic regression was performed to obtain the odds ratios (OR) for subnormal total testosterone (<300 ng/dL) or free testosterone (<6 ng/dL) in prediabetic and diabetic men compared with normoglycemic individuals, while adjusting for age, BMI, waist circumference, and metabolic syndrome (MetS). Results Normoglycemia, prediabetes, and diabetes were diagnosed in 577 (44.2%), 543 (41.6%), and 186 (14.2%) men, respectively. Prediabetes was associated with an increased risk of subnormal total testosterone compared to normoglycemic individuals (age-adjusted OR=1.87; 95%CI=1.38-2.54). The risk remained significant in all multivariate analyses. After adjusting for MetS, the OR in prediabetic men equals that of diabetic patients (1.49 versus 1.50). IFG, IPG, and HbA1c 5.7%-6.4% were all associated with an increased risk of testosterone deficiency, with different levels of significance in multivariate analyses. However, neither prediabetes nor diabetes was associated with subnormal free testosterone in multivariate analyses. Conclusions Prediabetes is associated with an increased risk of testosterone deficiency, independent of obesity and MetS. After adjusting for MetS, the risk equals that of diabetes. Our data suggest that testosterone should be measured routinely in men with prediabetes.