Bioactive staurosporine derivatives from the Streptomyces sp. NB-A13.

Six new (1-6) and nine known (7-15) staurosporine derivatives were isolated from the rice solid fermentation of the marine-derived Streptomyces sp. NB-A13. The structures of the new staurosporine derivatives were established by extensive spectroscopic data interpretation. The absolute configurations of 1 and 2 were assigned by quantum chemical calculations of the electronic circular dichroism (ECD) spectra. All of these compounds were screened for their cytotoxic activities against PC-3 and SW-620 cell lines. Compound 7 exhibited stronger inhibitory activity against SW-620 cell lines than the positive control staurosporine (25.10 nM), with IC50 values of 9.99 nM. Moreover, compounds 1-5, 8-13 and 15 also showed significant cytotoxicities with IC50 values ranging from 0.02 to 16.60 µM, while 6 exhibited no cytotoxic potency. Additionally, compounds 1-7 were also tested for enzyme inhibition activities of Protein kinase C theta (PKC-θ), and showed activity with IC50 values ranging from 0.06 to 9.43 µM except for compound 6, which has no inhibition activity.

Role of CCL20/CCR6 and the ERK signaling pathway in lung adenocarcinoma.

Previous studies have revealed that carcinoma-associated fibroblasts communicate microenvironment-derived signals through chemokine/chemokine receptor interaction, resulting in carcinogenesis. C-C motif chemokine ligand 20 (CCL20)/C-C motif chemokine receptor 6 (CCR6) interactions are involved in the pathogenesis of colonic malignancies. The present study aimed to characterize the roles of CCL20/CCR6 and the extracellular signal-regulated kinase (ERK) signaling pathway in lung adenocarcinoma growth. Lung adenocarcinoma samples obtained at surgery were assessed for the expression, tissue localization and production of CCL20/CCR6. In addition, colony formation, ERK signaling and chemokine production were measured to assess the responsiveness of the A549 cell line to CCL20 stimulation. CCL20 and CCR6 were found to be highly expressed in the majority of samples in the recurrence group (76 and 66%, respectively). The staining indexes of CCL20 and CCR6 in the recurrence group were 149.3 and 134.4, respectively, which were significantly higher than those in the non-recurrence group (57.2 and 58.0, respectively); the protein and mRNA expression levels determined by western blot and reverse transcription-quantitative polymerase chain reaction were also found to be high in the recurrence group For A549 cells, the colony-forming capacity was increased by CCL20 stimulation, and this effect was dependent in part on ERK phosphorylation. Collectively, the findings suggest that CCR6 and CCL20 may serve a role in lung adenocarcinoma, leading to proliferation and migration via autocrine or paracrine mechanisms. The disruption of CCL20/CCR6 interactions may be a promising strategy for the treatment of cancer.

Impact of activating transcription factor 4 signaling on lipogenesis in HepG2 cells.

Non-alcoholic fatty liver disease (NAFLD) is a rapidly growing health threat that has previously been associated with lipogenesis. The direct effect of endoplasmic reticulum stress (ERS) inhibition on the induction of lipogenesis has not been investigated in hepatocytes in vitro. The impact of activating transcription factor­4 (ATF4) on the lipogenic pathway and hepatic insulin transduction in liver cells also requires further investigation. In the present study, the triglyceride (TG) content of HepG2 cells stimulated with fructose was investigated using a commercially available enzymatic assay, and the expression levels of lipogenesis­associated factors were determined by western blotting and reverse transcription­quantitative polymerase chain reaction. Notably, the TG content of HepG2 cells was increased following incubation with fructose, which was accompanied by ERS. 4­Phenylbutyric acid, an inhibitor of ERS, lowered the TG content by reducing the mRNA expression levels of sterol regulatory element­binding protein 1 (SREBP­1c) and carbohydrate­responsive element­binding protein (ChREBP), and the protein expression levels of fatty acid synthase (FAS), acetyl­CoA carboxylase (ACC) and stearoyl­CoA desaturase­1 (SCD­1). Conversely, tunicamycin, which is an inducer of ERS, increased the TG content and stimulated the expression of the above lipogeneic markers. ATF4 deficiency relieved TG accumulation and decreased the mRNA expression levels of SREBP­1c and ChREBP, and protein expression levels of FAS, ACC and SCD­1 in fructose­treated HepG2 cells. Conversely, ATF4 overexpression increased the TG content by upregulating the mRNA expression levels of SREBP­1c and ChREBP and protein expression levels of FAS, ACC and SCD­1. Inhibition of ERS was shown to protect HepG2 cells against fructose­induced TG accumulation, whereas induction of ERS stimulated hepatic lipogenesis. As a downstream transcription factor of the unfolded protein response, a deficiency in ATF4 attenuates fructose­induced lipogenesis; while an overexpression of ATF4 can induce TG accumulation through stimulating hepatic lipogenesis. The results of the present study suggested that ATF4 may exert various physiological roles in lipid metabolism depending on the nutrient composition. In addition, these results suggested that ATF4 has a role in regulating lipogenesis and in the development of NAFLD; thus ATF4 may be considered a therapeutic target for NAFLD.

A case of membranous nephropathy and myeloperoxidase anti-neutrophil cytoplasmic antibody-associated glomerulonephritis.

Membranous nephropathy (MN) may be a primary disease or secondary to autoimmune conditions such as systemic lupus erythematosus, infection (for example, with hepatitis B or C virus), cancer or drugs. In primary MN, crescents are rarely observed. Therefore, the presence of crescents suggests another underlying disease, for example lupus nephritis, anti-glomerular basement membrane disease or anti-neutrophil cytoplasmic antibody-associated glomerulonephritis (ANCA-GN). The coexistence of primary MN and ANCA-GN is rare. In the present case, a 51-year-old female with mild edema in the lower extremities for 1 year was admitted to hospital for renal biopsy. The serum test for myeloperoxidase (MPO)-ANCA was positive. The patient was diagnosed with stage 2 MN with crescentic glomerulonephritis type 3; however, no causal association was found between these two diseases in this case. Treatment was initiated with 500 mg methylprednisolone for 3 days followed by 40 mg of oral methylprednisolone together with 50 mg cyclophosphamide twice per day. One month following treatment, the biochemical data results of the patient had improved.

Associations between apolipoprotein CIII concentrations and microalbuminuria in type 2 diabetes.

Microalbuminuria (MAU) is a strong predictor of diabetic nephropathy (DN), which is the main cause of morbidity and mortality in patients with diabetes mellitus (DM). Dyslipidemia exists in the majority of patients with DM and contributes to micro- and macrovascular complications associated with DM. Apolipoprotein CIII (apoCIII) is an inhibitor of the activity of lipoprotein lipase, which metabolizes triglyceride (TG) in very low-density lipoprotein (VLDL) and facilitates its clearance from plasma. The aim of the present study was to investigate the associations between apoCIII and MAU and the effects of atorvastatin in type 2 diabetes. In total, 120 subjects were divided into type 2 diabetes and type 2 DN groups, while 60 healthy subjects were selected as controls. The patients with DN were administered 20 mg atorvastatin daily for 16 weeks. Blood pressure, body mass index (BMI) and levels of HbA1c, FBG, TG, VLDL-cholesterol (VLDL-C), apoCIII and MAU were markedly elevated in the type 2 diabetes and type 2 DN groups compared with those in the control group (P<0.01), while high-density lipoprotein-cholesterol (HDL-C) levels were decreased significantly (P<0.01). All patients with type 2 DN showed significantly elevated blood pressure, apoCIII levels, MAU, course of the disease and rate of stroke and retinopathy compared with the patients with type 2 diabetes (P<0.01). MAU was significantly positively correlated with the course of the disease, systolic blood pressure, diastolic blood pressure, BMI and HbA1c, FBG, TG, total cholesterol, low-density lipoprotein-cholesterol, VLDL-C and apoCIII levels (P<0.05), whereas negatively correlated with HDL-C levels (r=-0.194, P=0.020). Logistic regression analysis showed that apoCIII levels were independently associated with MAU (odds ratio, 1.100; 95% confidence interval, 1.037-1.153; P<0.001). Atorvastatin improved the lipid profile and MAU in patients with type 2 DN (P<0.01). Therefore, the present study demonstrated that an independent positive correlation exists between the levels of apoCIII and MAU in patients with type 2 diabetes. Furthermore, atorvastatin may be used to improve the lipid profile and MAU in type 2 DN.

Unprecedent aminophysalin from Physalis angulata.

The 95% ethanol extract of the whole plant of Physalis angulata Linn. afforded one new skeletal physalin named aminophysalin A (1) and one new naturally occurring 5ß-hydroxy-6a-chloro-5,6-dihydrophysalin B (2), together with five known physalins (3-7). Their structures were elucidated through MS, IR, NMR spectroscopy analyses and X-ray crystallography. Aminophysalin A (1) had an absolutely unusual structural feature in the chemistry of physalins with a nitrogen atom. Compounds 1-7 were evaluated for quinone reductase activities in hepa 1c1c7 cells. Physalin H (6) showed strong quinone reductase induction activity with IR (Induction ratio, QR induction activity) value of 3.74±0.02, using 4-bromoflavone as a positive control substance (2.17±0.01, 10 µg/mL), while compounds 1, 2, 3, 5 showed weak quinone reductase induction activity.

The chemical chaperon 4-phenylbutyric acid ameliorates hepatic steatosis through inhibition of de novo lipogenesis in high-fructose-fed rats.

Non-alcoholic fatty liver disease caused by dietary factors such as a high fructose intake is a growing global concern. The aim of this study was to investigate the intervention effects of an endoplasmic reticulum stress (ERS) inhibitor 4-phenylbutyric acid (PBA) on liver steatosis induced by high-fructose feeding in rats and the possible underlying mechanisms. Wistar rats were divided into the control, high-fructose group (HFru) and PBA intervention (HFru-PBA) groups. PBA intervention was initiated following 4 weeks of high-fructose feeding. After 8 weeks of feeding, the ERS markers p-PERK, p-eIF2α, p-IRE-1, spliced XBP-1, ATF-6 were measured by western blotting. Liver triglyceride contents and morphological changes were examined. The protein expression of lipogenic key enzymes (ACC, FAS and SCD-1) and upstream transcriptional factors (SREBP-1c and ChREBP) were measured. The ERS-related cell events, oxidative stress and apoptosis, were evaluated by standard methods. Results demonstrated that PBA intervention significantly resolved hepatic ERS and improved liver steatosis induced by high-fructose feeding in rats. The protein expression of ACC, FAS, SCD-1 and SREBP-1c was upregulated in high-fructose-fed rats, whereas it decreased following PBA intervention. Oxidative stress and apoptosis were observed in livers of high-fructose-fed rats, but were alleviated by PBA intervention. ERS is involved in the development of fatty liver induced by a high fructose intake. ERS inhibition by PBA can therefore ameliorate liver steatosis through inhibition of hepatic lipogenesis.

Oxymatrine attenuates hepatic steatosis in non-alcoholic fatty liver disease rats fed with high fructose diet through inhibition of sterol regulatory element binding transcription factor 1 (Srebf1) and activation of peroxisome proliferator activated receptor alpha (Pparα).

The aim of this study was to examine the therapeutic effect of oxymatrine, a monomer isolated from the medicinal plant Sophora flavescens Ait, on the hepatic lipid metabolism in non-alcoholic fatty liver (NAFLD) rats and to explore the potential mechanism. Rats were fed with high fructose diet for 8 weeks to establish the NAFLD model, then were given oxymatrine treatment (40, 80, and 160 mg/kg, respectively) for another 8 weeks. Body weight gain, liver index, serum and liver lipids, and histopathological evaluation were measured. Enzymatic activity and gene expression of the key enzymes involved in the lipogenesis and fatty acid oxidation were assayed. The results showed that oxymatrine treatment reduced body weight gain, liver weight, liver index, dyslipidemia, and liver triglyceride level in a dose dependant manner. Importantly, the histopathological examination of liver confirmed that oxymatrine could decrease the liver lipid accumulation. The treatment also decreased the fatty acid synthase (FAS) enzymatic activity and increased the carnitine palmitoyltransferase 1A (CPT1A) enzymatic activity. Besides, oxymatrine treatment decreased the mRNA expression of sterol regulatory element binding transcription factor 1(Srebf1), fatty acid synthase (Fasn), and acetyl CoA carboxylase (Acc), and increased the mRNA expression of peroxisome proliferator activated receptor alpha (Pparα), carnitine palmitoyltransferase 1A (Cpt1a), and acyl CoA oxidase (Acox1) in high fructose diet induced NAFLD rats. These results suggested that the therapeutic effect of oxymatrine on the hepatic steatosis in high fructose diet induced fatty liver rats is partly due to down-regulating Srebf1 and up-regulating Pparα mediated metabolic pathways simultaneously.