The pro-inflammatory cytokine tumor necrosis factor α stimulates expression of the carnitine transporter OCTN2 (novel organic cation transporter 2) and carnitine uptake via nuclear factor-κB in Madin-Darby bovine kidney cells

Carnitine uptake into tissues is mediated mainly by the novel organic cation transporter 2 (OCTN2), whose expression is upregulated in the liver of early-lactating dairy cows. It has been shown recently that pro-inflammatory cytokines, including tumor necrosis factor α (TNFα), stimulate OCTN2 expression and carnitine uptake in intestinal cells and inflamed intestinal mucosa. Given that many early-lactating dairy cows show typical signs of hepatic and systemic inflammation, such as elevated concentrations of circulating TNFα and activation of the key regulator of inflammation, nuclear factor κB (NF-κB), in tissues, it is possible that upregulation of OCTN2 and increase of carnitine uptake by TNFα is mediated by NF-κB, a mechanism that might contribute to the upregulation of OCNT2 in the liver of early-lactating dairy cows. Thus, in the present study, we tested the hypothesis that TNFα stimulates OCTN2 gene expression and carnitine uptake via NF-κB in the bovine Madin-Darby bovine kidney (MDBK) cell line. Treatment with TNFα caused activation of NF-κB, increased the mRNA and protein concentration of OCTN2, and stimulated the uptake of carnitine in MDBK cells. In contrast, combined treatment of MDBK cells with TNFα and the NF-κB inhibitor BAY 11-7085 completely blocked the effect of TNFα on OCTN2 mRNA and protein concentration and uptake of carnitine. These findings suggest that the bovine OCTN2 gene and carnitine uptake are regulated by NF-κB. Future studies are required to show the in vivo relevance of this regulatory mechanism in cattle.

Upregulated sirtuin 1 by miRNA-34a is required for smooth muscle cell differentiation from pluripotent stem cells

microRNA-34a (miR-34a) and sirtuin 1 (SirT1) have been extensively studied in tumour biology and longevity/aging, but little is known about their functional roles in smooth muscle cell (SMC) differentiation from pluripotent stem cells. Using well-established SMC differentiation models, we have demonstrated that miR-34a has an important role in SMC differentiation from murine and human embryonic stem cells. Surprisingly, deacetylase sirtuin 1 (SirT1), one of the top predicted targets, was positively regulated by miR-34a during SMC differentiation. Mechanistically, we demonstrated that miR-34a promoted differentiating stem cells' arrest at G0/G1 phase and observed a significantly decreased incorporation of miR-34a and SirT1 RNA into Ago2-RISC complex upon SMC differentiation. Importantly, we have identified SirT1 as a transcriptional activator in the regulation of SMC gene programme. Finally, our data showed that SirT1 modulated the enrichment of H3K9 tri-methylation around the SMC gene-promoter regions. Taken together, our data reveal a specific regulatory pathway that miR-34a positively regulates its target gene SirT1 in a cellular context-dependent and sequence-specific manner and suggest a functional role for this pathway in SMC differentiation from stem cells in vitro and in vivo.

Effects of tetra-arsenic tetra-sulfide on BXSB lupus-prone mice: a pilot study

Systemic lupus erythematosus (SLE) is an autoimmune disease of uncertain etiology that affects multiple tissues and organs. Arsenic trioxide (ATO) has been used in lupus-prone mice with a regulatory effect on immune abnormality. Tetra-arsenic tetra-sulfide (As4S4), a traditional Chinese medicine, is effective on acute promyelocytic leukemia with mild side effects than ATO. In this study, a pilot study was performed to investigate the effects and the mechanism of As4S4 on the lupus-prone BXSB mice. Improvement of monocytosis (p<0.05) in spleen and decreased serum interleukin-6 (IL-6) (p=0.0277) were observed with As4S4 treatment. As4S4-treated mice exhibited amelioration of skin, liver and renal disease with mild side effects. Histological analysis revealed that As4S4 suppressed immune complex deposition, mesangial proliferation and inflammatory cell infiltration in kidney and liver. Our study support that As4S4 selectively suppresses cutaneous lupus and nephritis in BXSB mice and might be a potential treatment for SLE.

Fingertip replantation at the eponychial level with venous anastomosis: an anatomic study and clinical application

We present an anatomic study of the vein distribution at the eponychial level, in order to standardize outpatient fingertip replantation. The cross sectional anatomy of 100 fingers was studied by dissection following dye injection. The distribution of the veins >0.3 mm was recorded on a pie-chart. Thirty fingers in 27 patients with fingertip amputations at the eponychial level were replanted by anastomosis of the palmar subcutaneous veins, to reconstruct the venous reflux of the amputated digits. The operations were aided by the anatomical study and confirmed that the palmar area is the preferred site for venous anastomosis Following a distal finger amputation at the level of the eponychial fold we propose starting the search for veins between the 3 to 5 o'clock or 7 to 9 o'clock positions, as these are the areas where there are most likely to be suitable veins.

Genetic analysis of differentiation of T-helper lymphocytes

In the human immune system, T-helper cells are able to differentiate into two lymphocyte subsets: Th1 and Th2. The intracellular signaling pathways of differentiation form a dynamic regulation network by secreting distinctive types of cytokines, while differentiation is regulated by two major gene loci: T-bet and GATA-3. We developed a system dynamics model to simulate the differentiation and re-differentiation process of T-helper cells, based on gene expression levels of T-bet and GATA-3 during differentiation of these cells. We arrived at three ultimate states of the model and came to the conclusion that cell differentiation potential exists as long as the system dynamics is at an unstable equilibrium point; the T-helper cells will no longer have the potential of differentiation when the model reaches a stable equilibrium point. In addition, the time lag caused by expression of transcription factors can lead to oscillations in the secretion of cytokines during differentiation.

MR imaging of cerebral extraventricular neurocytoma: a report of 9 cases

Extraventricular neurocytoma is a rare entity, most frequently occurring in brain parenchyma outside the ventricular system. The purpose of this study was to characterize the MR imaging findings in a series of 9 patients with EVN verified by results of pathologic examination. All 9 EVNs were solitary and intracranially located. Eight lesions were well demarcated, and 3 showed intratumoral hemorrhage. The solid parts of 7 tumors were primarily isointense on T1-weighted images and heterogeneously enhanced on T1WI with contrast. Although cerebral EVNs can present a wide spectrum of appearances on MR, the imaging patterns appear to vary according to anatomic location and cellularity. Lesions in frontal or parietal lobes often present as well-demarcated large masses with cystic degeneration, hemorrhage, mild-to-moderate edema, and inhomogeneous enhancement. Moreover, the general isointensity of the solid parts of EVN on T1WI may be of some specificity.

Upregulation of Ras/Raf/ERK1/2 signaling and ERK5 in the brain of autistic subjects

Autism is a neurodevelopmental disorder characterized by impairments in social interaction, verbal communication and repetitive behaviors. A number of studies have shown that the Ras/Raf/ERK1/2 (extracellular signal-regulated kinase) signaling pathway plays important roles in the genesis of neural progenitors, learning and memory. Ras/Raf/ERK1/2 and ERK5 have also been shown to have death-promoting apoptotic roles in neural cells. Recent studies have shown a possible association between neural cell death and autism. In addition, two recent studies reported that a deletion of a locus on chromosome 16, which included the mitogen-activated protein kinase 3 (MAPK3) gene that encodes ERK1, is associated with autism. Most recently, our laboratory detected that Ras/Raf/ERK1/2 signaling activities were significantly enhanced in the brain of BTBR mice that model autism, as they exhibit many autism-like behaviors. We thus hypothesized that Ras/Raf/ERK1/2 signaling and ERK5 could be abnormally regulated in the brain of autistic subjects. In this study, we show that the expression of Ras protein was significantly elevated in the frontal cortex of autistic subjects. C-Raf phosphorylation was increased in the frontal cortex, while both C-Raf and A-Raf activities were enhanced in the cerebellum of autistic subjects. We also detected that both the protein expression and activities of ERK1/2 were significantly upregulated in the frontal cortex of autistic subjects, but not in the cerebellum. Furthermore, we showed that ERK5 protein expression is upregulated in both frontal cortex and cerebellum of autistic subjects. These results suggest that the upregulation of Ras/Raf/ERK1/2 signaling and ERK5 activities mainly found in the frontal cortex of autistic subjects may be critically involved in the pathogenesis of autism.

Inhibition of the pro-inflammatory NF-κB pathway by a grape seed and grape marc meal extract in intestinal epithelial cells

In pigs and other monogastric animal, the weaning phase is commonly accompanied by an increased susceptibility to gut disorders such as diarrhoea owing to the induction of an inflammatory process in the intestine during weaning. Given the unfavourable effects of intestinal inflammation on feed consumption, digestive capacity of the intestine and growth of animals, controlling intestinal inflammation is a reasonable approach for the maintenance of performance characteristics of livestock animals. Therefore, this study aimed to study the anti-inflammatory potential of a commercial polyphenol-rich grape seed (GS) and grape marc (GM) meal-based feed additive in a well-established in vitro intestinal epithelium model (polarized Caco-2 cells). The anti-inflammatory potential was evaluated by studying the effect of an ethanolic extract obtained from the GS and GM meal-based feed additive (GSGME) on the pro-inflammatory transcription factor NF-κB, which is considered to play a key role in the induction of weaning-associated intestinal inflammation. The highest non-cytotoxic concentrations of the ethanolic GSGME dose dependently reduced TNFα-induced NF-κB transactivation and decreased TNFα-induced mRNA levels of the NF-κB target genes IL-1β, IL-8, MCP-1 and CXCL1 in Caco-2 intestinal cells (p < 0.05). No effect of the ethanolic GSGME was observed on the cytoprotective Nrf2 pathway in Caco-2 cells as evidenced by an unaltered Nrf2 transactivation and unchanged mRNA levels of Nrf2 target genes, such as GPX-2, NQO1, CYP1A1 and UGT1A1. In conclusion, this study shows that an ethanolic GSGME exerts anti-inflammatory effects in intestinal cells under in vitro conditions. Thus, polyphenol-rich GSGM meal-based feed additives may be useful for the inhibition or prevention of inflammatory processes in the intestine of livestock animals, in particular during states with inappropriate NF-κB activation in the intestinal tissue, such as the weaning phase. Future studies are warranted to prove the in vivo anti-inflammatory potential of GSGM meal-based feed additives.

Primary intracranial choriocarcinoma: MR imaging findings

PICCC is the rarest, most malignant primary intracranial GCT. The purpose of this study was to describe and characterize the MR imaging findings in a series of 7 patients (6 males and 1 female; mean age, 11.9 years) with pathologically proved PICCC in our institution from 2004 to 2009. All tumors were located within the pineal (n = 6) or suprasellar (n = 1) regions. On T2-weighted MR imaging, the lesions appeared markedly heterogeneous with areas of both hypointensity and hyperintensity reflecting the histologic heterogeneity, including hemorrhage, fibrosis, cysts, or necrosis. Heterogeneous (n = 7), ringlike (n = 4), and/or intratumoral nodular (n = 3) enhancement was noted on T1-weighted images with gadolinium. These MR imaging findings, combined with patient age and serum β-HCG levels, may prove helpful in distinguishing PICCC from the more common primary brain tumors, thereby avoiding biopsy of this highly vascular tumor.

Phosphoproteomic profiling of arsenite-treated human small airway epithelial cells

Arsenic is well documented as a chemotherapeutic agent capable of inducing cell death; however, it is also considered as a human carcinogen. Although it has recently been shown that arsenite exposure can potentiate genotoxicity, little is known about its global effects exerted in cells at the proteome level. Immortalized human small airway epithelial cells exposed to arsenite were used to identify phosphoproteins of two major signaling cascades, such as the human phospho-receptor tyrosine kinase (Phospho-RTK) and the mitogen-activated protein kinases (MAPKs). These two arrays included several phosphoproteins, such as EGFR, ErbB2, ErbB4, InsulinR, Flt-3, extracellular signal-regulated kinases (ERK1/2), intracellular kinases such as AKT, GSK-3, c-Jun N-terminal kinases (JNK1-3) and different p38 isoforms (alpha/beta/delta/gamma). In arsenite-treated cells, phosphorylation of EGFR, InsulinR and Flt3R showed an increase when compared to their non-arsenite treated counterparts. Inhibitors of these proteins further confirmed the involvement of such proteins in the neoplasm transformation of arsenite-treated human small airway epithelial cells as seen in changes in plating efficiency, anchorage-independent growth and proliferation rate. It can be concluded that analysis of phosphoprotein by using phosphoproteomic profiling can be very useful to understand the mechanism of arsenite-induced carcinogenesis.

Identification and characterization of the NTPase activity of classical swine fever virus (CSFV) nonstructural protein 3 (NS3) expressed in bacteria

The nonstructural protein 3 (NS3) of members of the family Flaviviridae possesses multiple enzyme activities that are likely to be essential for viral replication. Here, we cloned and expressed full-length CSFV NS3 protein (NS3FL) and its N-terminal truncated version (ntNS3) in E. coli. NTPase activities of the purified NS3FL and ntNS3 proteins and their reaction conditions were investigated. The results showed that CSFV NS3FL and ntNS3 proteins contained a specific polynucleotide-stimulated NTPase acitivity. Characterization of ntNS3 NTPase activity showed that optimal reaction conditions with respect to pH, MgCl2 and monovalent cations were similar to those of bovine viral diarrhea virus (BVDV) and hepatitis C virus (HCV). Site-directed mutagenesis analysis demonstrated that the GxGK(232)T to GxGAT mutation in the conserved motif I abolished the NTPase activity of ntNS3, whereas substitution of TATPA(354) for TATPV in the motif III had no effect on the enzyme activity. Moreover, the kinetic properties (K(m) and k(cat)) of CSFV NS3 were more similar to those of BVDV. Our results provide insight into the structure-function relationship of CSFV NS3 and facilitate our understanding of its role in the replication cycle of CSFV.