USP33 promotes nonalcoholic fatty acid disease-associated fibrosis in gerbils via the c-myc signaling.

Nonalcoholic fatty acid disease (NAFLD) is a common complication of obesity associated with liver fibrosis. The underlying molecular mechanisms involved in the progression from normal to fibrosis remain unclear. Liver tissues from the liver fibrosis model identified the USP33 gene as a key gene in NAFLD-associated fibrosis. USP33 knockdown inhibited hepatic stellate cell activation and glycolysis in gerbils with NAFLD-associated fibrosis. Conversely, overexpression of USP33 caused a contrast function on hepatic stellate cell activation and glycolysis activation, which was inhibited by c-Myc inhibitor 10058-F4. The copy number of short-chain fatty acids-producing bacterium Alistipes sp. AL-1, Mucispirillum schaedleri, Helicobacter hepaticus in the feces, and the total bile acid level in serum were higher in gerbils with NAFLD-associated fibrosis. Bile acid promoted USP33 expression and inhibiting its receptor reversed hepatic stellate cell activation in gerbils with NAFLD-associated fibrosis. These results suggest that the expression of USP33, an important deubiquitinating enzyme, is increased in NAFLD fibrosis. These data also point to hepatic stellate cells as a key cell type that may respond to liver fibrosis via USP33-induced cell activation and glycolysis.

Inhibitory Effects of 2-Aminoethoxydiphenyl Borate (2-APB) on Three KV1 Channel Currents.

2-Aminoethoxydiphenyl borate (2-APB), a boron-containing compound, is a multitarget compound with potential as a drug precursor and exerts various effects in systems of the human body. Ion channels are among the reported targets of 2-APB. The effects of 2-APB on voltage-gated potassium channels (KV) have been reported, but the types of KV channels that 2-APB inhibits and the inhibitory mechanism remain unknown. In this paper, we discovered that 2-APB acted as an inhibitor of three representative human KV1 channels. 2-APB significantly blocked A-type Kv channel KV1.4 in a concentration-dependent manner, with an IC50 of 67.3 µM, while it inhibited the delayed outward rectifier channels KV1.2 and KV1.3, with IC50s of 310.4 µM and 454.9 µM, respectively. Further studies on KV1.4 showed that V549, T551, A553, and L554 at the cavity region and N-terminal played significant roles in 2-APB's effects on the KV1.4 channel. The results also indicated the importance of fast inactivation gating in determining the different effects of 2-APB on three channels. Interestingly, a current facilitation phenomenon by a short prepulse after 2-APB application was discovered for the first time. The docked modeling revealed that 2-APB could form hydrogen bonds with different sites in the cavity region of three channels, and the inhibition constants showed a similar trend to the experimental results. These findings revealed new molecular targets of 2-APB and demonstrated that 2-APB's effects on KV1 channels might be part of the reason for the diverse bioactivities of 2-APB in the human body and in animal models of human disease.

Severe Fanconi Anemia phenotypes in Fancd2 depletion mice.

Fanconi anemia (FA) is a genetic disorder characterized by congenital malfunction, bone marrow failure and hypersensitivity to DNA damage. FANCD2 protein play the central role in FA pathway. To study the in vivo role of FANCD2, we generated and characterized a new Fancd2 knockout mouse strain with 7bp deletion in Fancd2 gene 5' terminus using Crispr-Cas9 in congenic C57BL/6J background. This Fancd2-/- mice displayed similar but overall more severe manifestation than the previous ES cell targeted Fancd2 model. These features include increased embryonic and postnatal lethality rate, higher incidence of microphthalmia, and more severe hypogonadism. The anemia we observed in this Fancd2-/- mice has not been described in other FA models. Further study indicated that the hematopoiesis deficiency was associated with increased apoptotic cell death, G2/M phase arrest and hypersensitivity to MMC and IR damage of Fancd2-/- bone marrow progenitor cells. Collectively, the resulting Fancd2-/- mice with higher resemblance of FA patient symptoms, will be useful in understand the parthenogenesis of pancytopenia and bone marrow failure in FA.

MicroRNA-203 accelerates apoptosis in LPS-stimulated alveolar epithelial cells by targeting PIK3CA.

The pathogenesis of endotoxin-induced acute lung injury (ALI) remains obscure and has not been well elucidated hitherto. Recently, microRNAs have distinct expression profiles in innate immunity, inflammation, and infection. However, the functions of microRNAs in ALI remain unknown. In this study, the functions of microRNAs in the development of ALI were investigated to identify potential drug targets. MicroRNA-203 (miR-203) expression in the lung tissues of lipopolysaccharide (LPS)-challenged mice was found to be significantly upregulated and peaked 5d post-LPS injection. MiR-203 overexpression in A549 cells significantly promoted cell apoptosis by inducing S-phase cell-cycle arrest. MiR-203 overexpression also inhibited the protein expression of phosphoinositide 3-kinase catalytic subunit alpha (PIK3CA), a direct target of miR-203 identified by bioinformatics, thereby suppressing the PI3K/Akt pathway. Moreover, repressed miR-203 effectively attenuated LPS-induced interstitial pneumonia. Therefore, regulating or inhibiting miR-203 may be of therapeutic potential in pneumonia and ALI.

Catalase-negative Staphylococcus lugdunensis strain with a novel point mutation in the catalase gene isolated from a patient with chronic suppurative otitis media.

This report describes the results of the sequence analysis of a methicillin-susceptible strain of catalase-negative Staphylococcus lugdunensis. Molecular characterization of the deduced sequence revealed a novel point mutation in the catalase gene. To our knowledge, this is the first report of a catalase-negative S. lugdunensis strain, although catalase-negative isolates of Staphylococcus aureus and Staphylococcus epidermidis have been previously reported.

Cardiac toxicity of Triptergium wilfordii Hook F. may correlate with its inhibition to hERG channel.

Tripterygium wilfordii Hook F. (TWHF) is a Chinese traditional medicine with cardiac toxicities. However, the mechanism of acute cardiac toxicity is not very clear. By using patch clamp techniques, we found that 0.05 mg/ml and 0.1 mg/ml of the aqueous crude extract of TWHF inhibit 21.4 ± 1.6% and 86.7 ± 5.7% (n = 5) of hERG current Amplitudes (IhERG) respectively. We further found that Celastrol, one of main components of TWHF, inhibits hERG with an IC50 of 0.83 µM. Additional mutagenesis studies show that mutations of T623A, S624A and F656A significantly alter the inhibition and S624A has the strongest effect, supported by our docking model. Our data suggest that inhibition of hERG channel activity by Celastrol contributed to TWHF cardiotoxicity.

Human umbilical cord mesenchymal stem cells pretreated with Angiotensin-II attenuate pancreas injury of rats with severe acute pancreatitis.

Mesenchymal stem cells (MSCs) pretreatment is an effective route for improving cell-based therapy of endothelial cell survival, vascular stabilization, and angiogenesis. We hypothesized that the application of human umbilical cord-MSCs (hUC-MSCs) pretreated with angiotensin-II (Ang-II) might be a potential therapeutic approach for severe acute pancreatitis (SAP). Therefore, the effect of Ang-II pretreated hUC-MSCs on SAP was investigated in vitro and in vivo. METHODS: In the present study, human umbilical cord-derived MSCs pretreated with or without Ang-II were delivered through the tail vein of rats 12 h after induction of SAP. Pancreatitis severity scores and serum lipase levels, as well as the levels of VEGF and VEGFR2 were evaluated. RESULTS: We found that the administration of Ang-II-MSCs significantly inhibited pancreatic injury, as reflected by reductions of pancreatitis severity scores, serum amylase and serum lipase levels. Furthermore, the reduced apoptotic rate and increased tube formation in human umbilical vein endothelial Cells (HUVEC) were found resulting from the administration of Ang-II-MSC-CM. Moreover, knockdown of VEGFR2 can block the effect of Ang-II-MSC-CM on preventing HUVEC from apoptosis, as well as the capacity of tube formation was also suppressed. In addition, the expression of increased Bcl-2 and alleviated caspase-3 were observed in HUVEC and HUVEC transfectants exposure to Ang-II-MSC-CM. CONCLUSION: Collectively, these results elucidated that the pretreatment of hUC-MSCs with Ang-II improved the outcome of MSC-based therapy for SAP via enhancing angiogenesis and ameliorating endothelial cell dysfunction in a VEGFR2 dependent manner.

Effect of interleukin-2 treatment combined with magnetic fluid hyperthermia on Lewis lung cancer-bearing mice.

The present study aimed to investigate the therapeutic effect of interleukin-2 (IL-2) treatment combined with magnetic fluid hyperthermia (MFH) on Lewis lung cancer-bearing mice. Magnetic fluids were prepared in vitro and directly injected into the tumors in the mice, which were subjected to an alternating magnetic field. The temperature in the tumor reached 43°C and was maintained by controlling the strength of magnetic field for 30 min. Twenty-four hours later, IL-2 was injected directly into the tumors. Mice were divided into four groups: Group I (control), II (MFH), III (IL-2) and IV (IL-2+MFH). The tumor grew gradually in groups II and IV (both P<0.05) compared to the control group. Histological analysis showed that the tumor cells underwent apoptosis and necrosis. Immunohistochemistry results demonstrated that heat-shock protein 70 and cluster of differentiation (CD) 8-positive and CD4-positive T cells were strongly expressed following hypothermia. Therefore, the present study provided evidence that IL-2 treatment combined with MFH improves the therapeutic effect on lung cancer-bearing mice.

[Effects of magnetic fluid hyperthermia induced by an alternative magnetic field on human carcinoma A549 cell in vitro].

BACKGROUND AND OBJECTIVE: Magnetic fluid hyperthermia (MFH) is a method of heat therapy using nanometer techniques and hyperthermia. It has the advantage of high specificity of targeting. The aim of this study is to detect the effects of MFH induced by an alternating magnetic field on human being carcinoma A549 cells in vitro. METHODS: A human adenocarcinoma cell line A549 was cultured with various concentrations of ferroferric oxide (Fe3O4) magnetic fluid (1.5-6.0) mg/mL and exposed to an alternative magnetic field (AMF) for 30 min. And then the optical density (OD) of viable cell, cytotocixity index, growth curve of cells, morphologic changes of cell, cell cycle and aposptosis were measured. RESULTS: The proliferation of the A549 cells were remarkably inhibited, the OD value of viable cells decreased and cytotoxity index (CI) increased; Apoptosis of the A549 cells were observed to have cell shrinkage, chromatin condensation, margination, unclear fragmentation and intact cell membrane by light and electron microscopy; The cells were inhibited in the stage S. CONCLUSIONS: MFH induced by AMF could inhibit the proliferation, which promotes apoptosis and arrest at S stage of the A549 cells.

Effect of magnetic fluid hyperthermia on lung cancer nodules in a murine model.

The purpose of the present study was to investigate the therapeutic effect of magnetic fluid hyperthermia (MFH) induced by an alternating magnetic field (AMF) on human carcinoma A549 xenograft in nude mice. An animal model of human lung cancer was established by subcutaneous injection of human lung cancer A549 cells in BALB/c nude mice. The xenograft mice were randomly divided into four groups and each group was treated with an injection of a different concentration of magnetic fluid: control, low-dose (67.5 mg/ml), medium-dose (90.0 mg/ml) and high-dose group (112.5 mg/ml), respectively. Following the injection (24 h), the tumor was heated in an AMF for 30 min. Tumor volumes were then measured every week. The therapeutic effect was assessed by measuring the tumor volume and weight. Pathological examination was performed with a light and electronic microscope following treatment. The temperature at the surface of the tumor in the low-, medium- and high-dose groups increased to 41.3, 44.5 and 46.8°C, respectively. The tumor grew significantly slower in the medium- and high-dose groups (both p<0.05) compared to the control group. Cytoclasis and apoptosis were detected under light and electron microscopy. In conclusion, MFH induced by AMF inhibited tumor growth and promoted apoptosis of human carcinoma A549 cells in a xenograft mice model.