Trehalose decreases mutant SOD1 expression and alleviates motor deficiency in early but not end-stage amyotrophic lateral sclerosis in a SOD1-G93A mouse model

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disorder for which there is currently no effective treatment. Studies indicate that enhancing autophagy in mouse models of neurodegenerative disease can ameliorate the behavioral symptoms and pathological damage associated with the accumulation of pathological mutant proteins such as mutant superoxide dismutase (SOD1). This study investigated the effects of trehalose treatment on both early and end-stage disease in a transgenic mouse model of ALS via short-term (30 days after administration) and long-term (from 60 days after administration to death) trehalose treatment experiments. Sixty-day-old female SOD1-G93A transgenic mice were treated daily with 2% (w/v) trehalose in their drinking water for 30 days and monitored until they reached a neurological score of four, whereupon they were euthanized by cervical dislocation. Neurological, rotarod performance test and hanging wire test scores were recorded and body weight monitored. After death, the spinal cord was removed to assess the number of motor neurons and to measure the expression of mutant SOD1, LC3-II and p62. Trehalose significantly reduced the levels of mutant SOD1 and p62 and increased LC3-II in the spinal cords of 90-day-old SOD1-G93A transgenic mice. Furthermore, trehalose treatment significantly postponed disease onset, lengthened the time it took to reach a neurological score of 2 and preserved motor function; however, trehalose became less effective at delaying further disease progression as the disease progressed beyond a neurological score of 2 and it failed to extend the survival of SOD1-G93A transgenic mice. Additionally, independent of autophagy, trehalose consistently inhibited microgliosis and astrogliosis throughout the entire duration of the study. In conclusion, trehalose may be a useful add-on therapy in conjunction with other ALS treatment options to alleviate symptoms in early-stage ALS.

Computed tomography and magnetic resonance imaging of multiple focal nodular hyperplasias of the liver with congenital absence of the portal vein in a Chinese girl: case report and review of the literature

Background

Patients with congenital absence of the portal vein (CAPV) often suffer from additional medical complications such as hepatic tumors and cardiac malformations.

Case presentation

Congenital absence of the portal vein (CAPV) is a rare malformation. We present a case of a 16-year-old Chinese girl with CAPV with multiple pathology-proven hepatic focal nodular hyperplasias (FNHs) and ventricular septal defect (VSD). The CT and MRI features of this case are described, and previously reported cases are reviewed.

Conclusions

CAPV is a rare congenital anomaly and in such patients, clarifying the site of portosystemic shunts, liver disease, and other anomalies is critical for appropriate treatment selection and accurate prognosis determination. Close follow-up, including laboratory testing and radiologic imaging, is recommended for all CAPV patients.

[Liver transplantation for irresectable hilar cholangiocarcinoma]

OBJECTIVE

To evaluate the outcome of patients with irresectable hilar cholangiocarcinoma undergoing orthotopic liver transplantation (OLT) and to identify the prognostic factors that could influence survival.

METHODS

The data of 18 patients who underwent OLT for irresectable hilar cholangiocarcinoma between June 2003 and October 2010 were analyzed retrospectively. There were 12 male and 6 female cases with median of 52 years(range from 34 to 65 years).Fifteen patients underwent modified piggyback liver transplantation, 2 patients underwent classical orthotopic liver transplantation and 1 patient underwent living donor liver transplantation. Data were evaluated regarding tumor size, pathologic stage, overall survival, recurrence rates and prognostic factors.

RESULTS

OLT with lymphadenectomy was received by 18 patients with hilar cholangiocarcinoma. Median time until tumor recurrence was 20.5 months(range from 6.0 to 33.0 months). Seventeen patients died during follow-up.Of these, 14 patients died from recurrent or metastatic diseases, 2 patients died from multiple organ dysfunction syndrome during peri-operative period, and one patient died from other cause. The median survival time was 29.5 months(range from 3.0 to 84.0 months). The overall survival rate and recurrence-free survival rate at 1, 3, and 5 year were 16/18, 8/18, 1/18 and 13/18, 2/18, 1/18, respectively.Lymph node metastases had a statistically significant negative impact on overall survival. The 1, 3, and 5 year survival rates were 6/7, 1/7,0 and 10/11, 7/11, 1/11 (P < 0.05) in lymph node-positive and lymph node-negative patients.

CONCLUSIONS

Acceptable survival rates can be achieved by OLT for irresectable hilar cholangiocarcinoma without lymph node metastases.Strict patient selection plus multimodal chemoradiation therapy prior to OLT are recommend for patients with lymph node metastases.

A new cellular model of pathological TDP-43: The neurotoxicity of stably expressed CTF25 of TDP-43 depends on the proteasome

The C-terminal fragments-25(CTF25) of TDP-43 is a fragment of TAR DNA-binding protein 43kDa (TDP-43), which is involved in RNA metabolism, neurite outgrowth, and neuronal development and stress granules. Not until recently did evidence suggest that CTF25 might play an important role in amyotrophic lateral sclerosis (ALS) pathogenesis. However, mechanical details on CTF25 causing motor neuron degeneration still remain unknown. To study the toxicity of CTF25 of TDP-43, we established a cellular model stably expressing CTF25 of TDP-43. Herein, we found that stably expressed CTF25 could induce significant oxidative stress and was mainly degraded by the proteasome pathway in cells. Furthermore, the neurotoxicity of CTF25 of TDP-43 was dependent on proteasome activity. In addition, electron microscopy showed mitochondrial swelling and cristae dilation in cells expressing CTF25 and that CTF25 aggregates were characterized by filamentous bundles and electron dense granular material. In conclusion, the new cellular model mimics classical toxic TDP-43 cellular model and interestingly the toxicity of CTF25 is dependent on the proteasome.

Protein serine/threonine Phosphotase-2A is differentially expressed and regulates eye development in vertebrates

Protein serine/threonine phosphatase-2A (PP-2A) is one of the key enzymes responsible for dephosphorylation in vertebrates. PP-2A-mediated dephosphorylation participates in many different biological processes including cell proliferation, differentiation, transformation, apoptosis, autophage and senescence. However, whether PP-2A directly controls animal development remains to be explored. Here, we present direct evidence to show that PP-2A displays important functions in regulating eye development of vertebrates. Using goldfish as a model system, we have demonstrated the following novel information. First, inhibition of PP-2A activity leads to significant death of the treated embryos, which is derived from blastomere apoptosis associated with enhanced phosphorylation of Bcl-XL at Ser-62, and the survived embryos displayed severe phenotype in the eye. Second, knockdown of PP-2A with morpholino oligomers leads to significant death of the injected embryos. The survived embryos from PP-2A knockdown displayed clear retardation in lens differentiation. Finally, overexpression of each catalytic subunit of PP-2A also causes death of majority of the injected embryos and leads to absence of goldfish eye lens or severely disturbed differentiation. Together, our results provide direct evidence that protein phosphatase-2A is important for normal eye development in goldfish.

Modified arterioportal shunting in radical resection of hilar cholangiocarcinoma

BACKGROUND/AIMS

The resection and reconstruction of hepatic artery is often required in radical surgery for hilar cholangiocarcinoma. In this study, we reported our experience in performing the arterioportal shunting with restriction of the arterial caliber as an alternative for the arterial reconstruction on the basis of our experiment when reconstruction of hepatic artery is impossible.

METHODOLOGY

Eight patients with hilar cholangiocarcinoma underwent extended left hepatectomy and caudate lobectomy combined with en bloc resection of hepatic artery and arterioportal shunting with restriction of the arterial caliber. The efficacy of arterioportal shunting and restriction of the arterial caliber in preventing complications of arterioportal shunting were assessed by computed tomography angiography (CTA) perioperational period and 2 years follow-up after the operation.

RESULTS

Eight patients recovered uneventfully without any complication. CTA showed a patent shunt and normal liver regeneration. No signs of portal hypertension were found in two years of follow-up.

CONCLUSIONS

Arterioportal shunting with restriction of the arterial caliber appears to be a feasible and safe alternative for the microvascular reconstruction after hepatic artery resection in radical surgery for hilar cholangiocarcinoma.

Experiences of microsurgical reconstruction for variant hepatic artery in living donor liver transplantation

There is an emergent need for improving the microsurgical technique of variant arterial anastomosis to reduce the often seen surgery-related complications. We describe in this article our experience in improving this technique, in 73 living donor liver grafts (64 right lobes, 9 left lobes) in patients with end-stage liver disease during living donor liver transplantation. The hepatic arteries were evaluated preoperatively with computed tomography and magnetic resonance angiography. In this series, 13 grafts (17.80 %) with variant hepatic artery were conducted arterioplasty on a back-table under a loupe or a high-power microscope, which included one recipient in situ interposition vessel graft of recipient proper hepatic artery for artery reconstruction. The back-table reconstruction time was 16 ± 5.6 min. No arterial thrombosis was found in these cases during the 6-month postoperative follow-up. On the basis of our experience, we suggest that back-table microsurgical plasty for graft with arterial variation should be applied to minimize operative difficulties and to avoid arterial complications in living donor liver transplantation.

Precision in liver surgery

Continuous theoretical and technological progress in the face of increasing expectations for quality health care has transformed the surgical paradigm. The authors systematically review these historical trends and propose the novel paradigm of "precision surgery," featuring certainty-based practice to ensure the best result for each patient with multiobjective optimization of therapeutic effectiveness, surgical safety, and minimal invasiveness. The main characteristics of precision surgery may be summarized as determinacy, predictability, controllability, integration, standardization, and individualization. The strategy of precision in liver surgery is to seek a balance of maximizing the removal of the target lesion, while maximizing the functional liver remnant and minimizing surgical invasiveness. In this article, the authors demonstrate the application of precision approaches in specific settings in complex liver surgery. They propose that the concept of precision surgery should be considered for wider application in liver surgery and other fields as a step toward the ultimate goal of perfect surgery.

Exposure to bisphenol A disrupts meiotic progression during spermatogenesis in adult rats through estrogen-like activity

The effect of bisphenol A (BPA) on the reproductive system is highly debated but has been associated with meiotic abnormalities. However, evidence is lacking with regard to the mechanisms involved. In order to explore the underlying mechanisms of BPA-induced meiotic abnormalities in adult male rats, we exposed 9-week-old male Wistar rats to BPA by gavage at 0, 2, 20 or 200 μg/kg body weight (bw)/day for 60 consecutive days. 17β-Estradiol (E2) was administered at 10 μg/kg bw/day as the estrogenic positive control. Treatments with 200 μg/kg bw/day of BPA and E2 significantly decreased sperm counts and inhibited spermiation, characterized by an increase in stage VII and decrease in stage VIII in the seminiferous epithelium. This was concomitant with a disruption in the progression of meiosis I and the persistence of meiotic DNA strand breaks in pachytene spermatocytes,and the ataxia-telangiectasia-mutated and checkpoint kinase 2 signal pathway was also activated; Eventually, germ cell apoptosis was triggered as evaluated by terminal dUTP nick-end labeling assay and western blot for caspase 3. Using the estrogen receptor (ER) antagonist ICI 182780, we determined that ER signaling mediated BPA-induced meiotic disruption and reproductive impairment. Our results suggest that ER signaling-mediated meiotic disruption may be a major contributor to the molecular events leading to BPA-related male reproductive disorders. These rodent data support the growing association between BPA exposure and the rapid increase in the incidence of male reproductive disorders.

Motion analysis of light-powered autonomous silver chloride nanomotors

Powered by UV light, nano/micrometer-sized silver chloride particles exhibit autonomous movement and form "schools" in aqueous solution, i.e. regions in which the number density of particles is significantly higher than the global average. In this paper, the silver chloride particles in such a system are classified by their proximity to other AgCl particles--be they isolated, coupled or schooled--and their motion paths are tracked and analyzed. By plotting time-averaged mean squared displacements of each particle over various time intervals from 0.1 s to 15.0 s, we discover different diffusive behaviors for the three classes of silver chloride particles.

P3-17-10: EpCAM as a Target for Chemical Antibodies in Metastatic Breast Cancer

EpCAM is a 40kDa glycoprotein that functions as an adhesion molecule in benign epithelium. However, it is over-expressed in nearly all carcinomas, including breast carcinomas, and has been implicated in the pathogenesis and progression of cancer. In primary breast carcinoma, its over-expression correlates with a diminished overall survival in patients with node-positive disease. Indeed, recent evidence has shown that EpCAM is expressed at a higher level in metastases than in matched primary breast carcinoma. This has led to the suggestion that EpCAM over-expression is associated with aggressive behaviour, and that it could be considered a promising therapeutic target for breast cancer. Several immunotherapy trials are ongoing, though there are limitations to their delivery and distribution, suggesting a smaller and more effective EpCAM targeting molecule is required.

Aptamers, also known as chemical antibodies, are short-stranded DNA or RNA molecules and are selected via the systematic evolution of ligands by exponential enrichment (SELEX). They are 10 to 20 times smaller than antibodies and exhibit superb tissue penetration, thereby indicating their suitability in cancer targeting. In addition, aptamers are more stable, non-immunogenic and non-toxic. Following 12 rounds of SELEX using EpCAM protein as a target, we generated several EpCAM specific RNA aptamers. These were investigated using flow cytometry and confocal microscopy for their ability to bind to three breast cancer cell lines, MCF-7, T47D and MDA-MB-231. Our 19-nt aptamer showed specific binding to all three cell lines. In addition, it also showed superior penetration of breast cancer 3-D spheroid tumor models, as compared to a control aptamer and negative cell lines. This aptamer has also shown efficient internalisation via receptor-mediated endocytosis, suggesting it to be a suitable targeting moiety for drug delivery to both primary and metastatic tumors. The usefulness of this aptamer in clinical applications is being actively investigated.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P3-17-10.

Aptasensors: a review

Aptamers are a promising class of agents for biomolecules detection due to their small size, chemical stability and cost effectiveness over conventional bioreceptors such as antibodies. Recent advances in micro/nano-fabrication and biotechnology have driven active participation of engineers and molecular biologists in the development of aptasensors. This review examines aptasensors from a developer standpoint discussing surface immobilization techniques and mechanisms used to detect biomolecular interactions in the context of biotechnology and nanomedicine. The factors that affect accuracy, sensitivity and stability of aptasensors are also addressed.

Mutant TAR DNA-binding protein-43 induces oxidative injury in motor neuron-like cell

Various missense mutations were identified in TAR DNA-binding protein-43 (TDP-43) in patients with amyotrophic lateral sclerosis (ALS). To explore the toxic effect of mutant TDP-43, we generated stable transfection of wild-type and mutant TDP-43 in motor neuron-like cell line. We found that mutant TDP-43 induced mitochondrial dysfunction, oxidative damage and nuclear accumulation of nuclear factor E2-related factor 2 (Nrf2). Nrf2 is an indicator and modulator of oxidative stress and is known to promote the expression of phase || detoxification enzyme including heme oxygenase-1 (HO-1). However, HO-1 was down regulated in cells expressing the mutant TDP-43, and could not be restored by sulforaphane which is a known stimulator of Nrf2 and phase || detoxification enzyme, including HO-1. Nevertheless, sulforaphane reduced the level of lactate dehydrogenase and lipoperoxidation products in cells expressing TDP-43 mutant. However, sulforaphane could upregulate the expression of HO-1 and NAD(P)H/quinone oxidoreductase-1 (NQO-1) in cells transfected with the empty vector and the wild-type TDP-43. Thus, sulforaphane protected cells against mutant TDP-43 independent of Nrf2-antioxidant response element (ARE) pathway. How mutant TDP-43 reduces expression of HO-1 and prevents sulforaphane from activating Nrf2 signaling remains to be investigated.

Role of ATP-binding cassette drug transporters in the intestinal absorption of tanshinone IIB, one of the major active diterpenoids from the root ofSalvia miltiorrhiza

There is an increasing use of herbal medicines worldwide, and the extracts from the root of Salvia miltiorrhiza are widely used in the treatment of angina and stroke. In this study, we investigated the mechanism for the intestinal absorption of tanshinone IIB (TSB), a major constituent of S. miltiorrhiza. The oral bioavailability of TSB was about 3% in rats with less proportional increase in its maximum plasma concentration (C(max)) and area under the plasma concentration-time curve (AUC) with increasing dosage. The time to C(max) (T(max)) was prolonged at higher oral dosage. In a single pass rat intestinal perfusion model, the permeability coefficients (P(app)) based on TSB disappearance from the lumen (P(lumen)) were 6.2- to 7.2-fold higher (p < 0.01) than those based on drug appearance in mesenteric venous blood (P(blood)). The uptake and efflux of TSB in Caco-2 cells were also significantly altered in the presence of an inhibitor for P-glycoprotein (PgP) or for multi-drug resistance associated protein (MRP1/2). TSB transport from the apical (AP) to basolateral (BL) side in Caco-2 monolayers was 3.3- to 5.7-fold lower than that from BL to AP side, but this polarized transport was attenuated by co-incubation of PgP or MRP1/2 inhibitors. The P(app) values of TSB in the BL-AP direction were significantly higher in MDCKII cells over-expressing MDR1 or MRP1, but not in cells over-expressing MRP2-5, as compared with the wild-type cells. The plasma AUC(0-24hr) in mdr1a and mrp1 gene-deficient mice was 10.2- to 1.7-fold higher than that in the wild-type mice. Furthermore, TSB significantly inhibited the uptake of digoxin and vinblastine in membrane vesicles containing PgP or MRP1. TSB also moderately stimulated PgP ATPase activity. Taken collectively, our findings indicate that TSB is a substrate for PgP and MRP1 and that drug resistance to TSB therapy and drug interactions may occur through PgP and MRP1 modulation.

Phase I and pharmacokinetic study of mitomycin C and celecoxib as potential modulators of tumor resistance to irinotecan in patients with solid malignancies

PURPOSE

Based on the preclinical evidence of topoisomerase I (Topo-1) upregulation by mitomycin C(MMC) and decreased NF-kappaB activation by celecoxib, we evaluated combinations of irinotecan/MMC and irinotecan/MMC/celecoxib in patients with advanced solid malignancies.

PATIENTS-METHODS

Initially, patients received MMC on day 1 and irinotecan on days 2, 8, 15 and 22, every 6 weeks. MMC dose was fixed at 6 mg/m(2) and cumulative doses of >36 mg/m(2) were not permitted. Irinotecan was escalated in 25 mg/m(2) increments. Due to late-onset diarrhea, the schedule was subsequently shortened to 4 weeks, omitting irinotecan on days 15 and 22. In the second part of the study, celecoxib 400 mg orally twice daily was added to irinotecan/MMC regimen. Potential pharmacokinetic interactions and Topo-1 and DT-diaphorase (NQ01) gene expressions in peripheral-mononuclear cells were evaluated.

RESULTS

Forty-five patients were enrolled. Irinotecan 125 mg/m(2) on days 2 and 8 in combination with MMC 6 mg/m(2) on day 1 every 4 weeks is recommended for future studies; myelosuppression and diarrhea are dose-limiting. The addition of celecoxib resulted in unacceptable toxicities despite reductions on irinotecan's dose. No relevant pharmacokinetic interactions occurred between irinotecan and MMC, and mean increases in Topo-1, were observed. Sixteen of 36 patients evaluable for response-assessment had discernable anti-tumor activity, including 1 complete, 4 partial, 10 minor and 1 tumor marker response. Four patients had prolonged (>4 months) disease-stability (stable disease, not included in CR or PR). Patients experiencing complete and partial responses had higher increments in Topo-1 expression.

CONCLUSIONS

Modulation of irinotecan by MMC is feasible, devoid of pharmacological interactions and active in solid malignancies. The lack of improvement in therapeutic index does not support the addition of celecoxib.

Sulfatide-tenascin interaction mediates binding to the extracellular matrix and endocytic uptake of liposomes in glioma cells

Tenascin-C is an extracellular matrix glycoprotein, whose expression is highly restricted in normal adult tissues, but markedly up-regulated in a range of tumors, and therefore serves as a potential receptor for targeted anticancer drug or gene delivery. We describe here a liposomal carrier system in which the targeting ligand is sulfatide. Experiments with tenascin-C-expressing glioma cells demonstrated that binding of liposomes to the extracellular matrix relied essentially on the sulfatide-tenascin-C interaction. Following binding to the extracellular matrix, the sulfatide-containing liposomes were internalized via both caveolae/lipid raft- and clathrin-dependent pathways, which would ensure direct cytoplasmic release of the cargoes carried in the liposomes. Such natural lipid-guided intracellular delivery targeting at the extracellular matrix glycoproteins of tumor cells thus opens a new direction for development of more effective anticancer chemotherapeutics in future.

A comparison study of cerebral protection using Ginkgo biloba extract and Losartan on stroked rats

It has been well documented that oxidative stress is involved in stroke. Currently, many neuroprotective strategies have been targeted at molecules that are able to act as an oxidant to intervene with free-radical mediated apoptosis in the ischemic penumbra. In particular, natural products which contain antioxidant properties have undoubtedly efficacious for stroke treatment. In the current study, therapeutic effects of Ginkgo biloba extract (EGb) against cerebral protection in Wistar rats underwent middle cerebral artery occlusion (MCAO) was evaluated. A comparison study was conducted by using Losartan, an antihypertensive drug. Gene expression levels of pro-apoptotic genes (AT2 receptor, Fas, Bax and Bcl-xS) have shown to have significant reduction by EGb- and Losartan-treated groups as compared to vehicle group. Significant reduction of immunoreactivity of protein production of these genes, together with least nuclear green fluorescence observed in TUNEL, EGb, as an antioxidant drug, is concluded to have potent and promising therapeutic effect for stroke treatment.