Construction of ureteral grafts by seeding bone marrow mesenchymal stem cells and smooth muscle cells into bladder acellular matrix

BACKGROUND

Congenital or acquired abnormalities may cause an ureteral injury or defect. The main methods to reconstruct a long ureter often cause serious complications. In this study, we sought to construct a tissue-engineered graft by seeding bone marrow mesenchymal stem cells (MSCs) and smooth muscle cells (SMCs) into a bladder acellular matrix (BAM) for ureteral reconstruction.

METHODS

Isolated, proliferated, and in vitro identified rabbit bone marrow MSCs and SMCs were seeded into BAM as the experimental group. Grafts only seeding SMCs were the control group. Cell-seeded grafts were used to construct tissue-engineered tubular grafts (TETG) for transplantation into the rabbit's omentum for 2 weeks before ureteral reconstruction. Evolutionary histology was performed at 2, 4, 8, and 16 weeks postoperatively. Renal function and ureteral obstruction were evaluated using intravenous urography at 16 weeks.

RESULTS

Flow cytometry demonstrated bone marrow MSCs to express CD29, CD44, CD90, but not CD34. Histological examination revealed consistent regeneration of TETG urothelium in the experimental group. At 8 and 16 weeks after TETG grafting in vivo, multilayer urothelium covered the entire lumen with visible neovascularization within the center. Organized smooth muscle bundles were observed. Intravenous urography demonstrated no ureteral stricture or hydronephrosis. The 5 rabbits were dead within 4 weeks postoperatively. Autopsy showed scar formation inside the graft with severe hydronephrosis.

CONCLUSION

We successfully constructed a TETG by seeding bone marrow MSCs and SMCs into BAM for ureteral reconstruction. Thus bone marrow MSCs can potentially promote urothelial regeneration to achieve a tissue-engineered ureter.

AQP1 expression alterations affect morphology and water transport in Schwann cells and hypoxia-induced up-regulation of AQP1 occurs in a HIF-1α-dependent manner

Aquaporin-1 (AQP1) is the principle water channel in the peripheral nervous system (PNS) and is specifically localized to Schwann cells in the PNS. However, the pathophysiological role of AQP1 in peripheral nerves is poorly understood. Here, we utilized RNA interference by lentiviral transduction to specifically down-regulate AQP1 expression and a lentiviral overexpression protocol to up-regulate AQP1 expression, in primary Schwann cell cultures. AQP1 gene silencing resulted in a cell shrinkage phenotype, while AQP1 gene overexpression caused a cell swelling phenotype, as validated by cell volume determinations. Secondly, we utilized an in vitro hypoxia model in Schwann cells to mimic in vivo facial nerve injury. We demonstrated that AQP1 expression was induced within 8h following hypoxia injury in vitro, and that AQP1 knockdown (KD) caused the cells to resist edema following hypoxia. Finally, we investigated the hypoxic regulation of the AQP1 gene, as well as the involvement of Hypoxia-inducible factor-1α (HIF-1α) in AQP1 modulation and we found that KD of HIF-1α decreased hypoxia-dependent induction of endogenous AQP1 expression at both the mRNA and protein levels. Taken together, these results indicate that (1) AQP1 is an important factor responsible for the fast water transport of cultured Schwann cells and is involved in cell plasticity; (2) AQP1 alterations may be a primary factor in hypoxia-induced peripheral nerve edema; (3) HIF-1α participates in the hypoxic induction of the AQP1 gene; (4) AQP1 inhibition might provide a new therapeutic alternative for the treatment of some forms of peripheral nerve edema.

Low-Dose Azithromycin Attenuates OVA-Induced Airway Remodeling and Inflammation via Down-Regulating TGF-βl Expression in RAT

Asthma is characteristic with chronic airway inflammation and remodeling. Azithromycin (AZM), the 15-member macrolide, is known to present an anti-inflammatory effect and is increasingly being used in the treatment of chronic inflammatory pulmonary diseases. We hypothesize that low-dose azithromycin can inhibit allergen-induced airway remodeling except allergic airway inflammation in rat model. Male SD rats underwent intraperitoneal ovalbumin sensitization on days 1 and 6 followed by an intranasal challenge on day 7–13. On day 14, airway inflammation and remodeling were assessed by quantifying leukocytes in the airway, expression of multiple inflammatory mediators in BALF, histological examination in lung and TGF-β1 mRNA and protein levels by qRT-PCR, immunohistochemistry and Western blotting. Treatment with low-dose azithromycin at the dose of 25 mg/kg significantly reduced ovalbumin-dependent airway inflammation, including accumulation of neutrophils, lymphocytes and eosinophils, secretion of IL-2, IL-4, IL-13 and TNF-α. Moreover, airway remodeling was significantly abrogated by azithromycin in this model. The mucus cell hyperplasia, thickening of the peribronchial smooth muscle layer, secretion of ET-1, IL-2, IL-4, IL-13 and TNF-α, and increasing mRNA and protein expressions of TGF-β1 in lung tissue were all significantly decreased in azithromycin-treated rats. These findings demonstrate the protective effect of low-dose azithromycin on allergic airway remodeling in rat and suggest low-dose azithromycin may have beneficial effects in treating allergic airway inflammation.

In vitro analysis of ovarian cancer response to cisplatin, carboplatin, and paclitaxel identifies common pathways that are also associated with overall patient survival

Background:

Carboplatin and cisplatin, alone or in combination with paclitaxel, have similar efficacies against ovarian cancer (OVCA) yet exhibit different toxicity profiles. We characterised the common and unique cellular pathways that underlie OVCA response to these drugs and analyse whether they have a role in OVCA survival.

Methods:

Ovarian cancer cell lines (n=36) were treated with carboplatin, cisplatin, paclitaxel, or carboplatin–paclitaxel (CPTX). For each cell line, IC₅₀ levels were quantified and pre-treatment gene expression analyses were performed. Genes demonstrating expression/IC₅₀ correlations (measured by Pearson; P<0.01) were subjected to biological pathway analysis. An independent OVCA clinico-genomic data set (n=142) was evaluated for clinical features associated with represented pathways.

Results:

Cell line sensitivity to carboplatin, cisplatin, paclitaxel, and CPTX was associated with the expression of 77, 68, 64, and 25 biological pathways (P<0.01), respectively. We found three common pathways when drug combinations were compared. Expression of one pathway (‘Transcription/CREB pathway’) was associated with OVCA overall survival.

Conclusion:

The identification of the Transcription/CREB pathway (associated with OVCA cell line platinum sensitivity and overall survival) could improve patient stratification for treatment with current therapies and the rational selection of future OVCA therapy agents targeted to these pathways.

Tumor development is associated with decrease of TET gene expression and 5-methylcytosine hydroxylation

The TET (ten-eleven translocation) family of α-ketoglutarate (α-KG)-dependent dioxygenases catalyzes the sequential oxidation of 5-methylcytosine (5mC) to 5-hydroxymethylcytosine (5hmC), 5-formylcytosine and 5-carboxylcytosine, leading to eventual DNA demethylation. The TET2 gene is a bona fide tumor suppressor frequently mutated in leukemia, and TET enzyme activity is inhibited in IDH1/2-mutated tumors by the oncometabolite 2-hydroxyglutarate, an antagonist of α-KG, linking 5mC oxidation to cancer development. We report here that the levels of 5hmC are dramatically reduced in human breast, liver, lung, pancreatic and prostate cancers when compared with the matched surrounding normal tissues. Associated with the 5hmC decrease is the substantial reduction of the expression of all three TET genes, revealing a possible mechanism for the reduced 5hmC in cancer cells. The decrease of 5hmC was also observed during tumor development in different genetically engineered mouse models. Together, our results identify 5hmC as a biomarker whose decrease is broadly and tightly associated with tumor development.

A novel way of visualizing the ductal and aortic arches by real-time three-dimensional ultrasound with live xPlane imaging

OBJECTIVE

To describe a novel method of visualizing the ductal and aortic arches by real-time three-dimensional echocardiography with live xPlane imaging.

METHODS

Live xPlane imaging was used to display the ductal- and aortic-arch views in 107 women with singleton pregnancies, including seven cases with suspected congenital heart defects (CHDs). The three vessels and trachea (3VT) view was obtained in such an orientation that either the pulmonary artery or the aorta was parallel to the direction of the ultrasound beam. The xPlane reference line was then placed across the targeted vessel, which in a normal case would provide an image of the corresponding arch view as a dual-image display.

RESULTS

Once the 3VT view had been obtained, live xPlane imaging showed the aortic and ductal arches in all 100 normal cases. In seven cases with suspected CHD, the 3VT view was abnormal in five cases and normal in the other two. However, the ductal-arch view demonstrated by live xPlane imaging was abnormal in five cases of conotruncal anomalies and normal in two cases in which conotruncal anomalies were excluded. CHDs were confirmed at autopsy following termination of pregnancy in five cases and on postnatal echocardiography in one case. The heart was found postnatally to be normal in one case of suspected CHD; in this case live xPlane imaging showed that the observed abnormal 3VT view was caused by a tortuous course of the thoracic aorta associated with an abnormal diaphragm.

CONCLUSION

Live xPlane imaging is a novel and relatively simple method of visualizing the ductal- and aortic-arch views, and may potentially be a useful tool in the screening of fetal conotruncal and aortic-arch anomalies.

Preliminary experience of endoscopic submucosal tunnel dissection for upper gastrointestinal submucosal tumors

BACKGROUND AND STUDY AIM

Although the majority of submucosal tumors (SMTs) are benign, some do have a malignant potential. Resection of SMTs would aid in establishing the diagnosis and may be curative. Our aim was to examine the feasibility and safety of a novel method for endoscopic resection of upper gastrointestinal SMTs.

PATIENTS AND METHODS

In 12 patients who presented with an upper gastrointestinal SMT of ≤40 mm located in the esophagus or cardia, a submucosal tunnel was endoscopically created starting approximately 5 cm proximal to the lesion. After careful submucosal dissection with carbon dioxide or air insufflation, the SMTs were completely removed, and the entrance of the tunnel closed using endoclips.

RESULTS

SMTs had a mean size of 19.5 mm (range 10-40 mm); eight were located in the esophagus and four in the cardia. SMT resection was successful in all patients with en bloc resection in 10 patients (83.3%) and resection in two pieces in the remaining two patients. The mean time required for the procedure was 48.3 minutes (range 30-60 minutes). Two patients had both pneumothorax and subcutaneous emphysema. All the complications resolved with conservative management.

CONCLUSIONS

In this pilot study, endoscopic submucosal tunnel dissection (ESTD) of esophageal and cardia SMTs was effective and appeared to be safe. Larger studies that also examine its application for gastric SMTs are warranted.

Regulation of glycolysis and gluconeogenesis by acetylation of PKM and PEPCK

Glycolysis is a catabolic process of glucose hydrolysis needed for energy and biosynthetic intermediates, whereas gluconeogenesis is a glucose production process important for maintaining blood glucose levels during starvation. Although they share many enzymes, these two processes are not simply the reverse of each other and are instead reciprocally regulated. Two key enzymes that regulate irreversible steps in these two processes are pyruvate kinase (PK) and phosphoenolpyruvate carboxy kinase (PEPCK), which catalyze the last and first step of glycolysis and gluconeogenesis, respectively, and are both regulated by lysine acetylation. Acetylation at Lys305 of the PKM (muscle form of PK) decreases its activity and also targets it for chaperone-mediated autophagy and subsequent lysosome degradation. Acetylation of PEPCK, on the other hand, targets it for ubiquitylation by the HECT E3 ligase, UBR5/EDD1, and subsequent proteasomal degradation. These studies established a model in which acetylation regulates metabolic enzymes via different mechanisms and also revealed cross talk between acetylation and ubiquitination. Given that most metabolic enzymes are acetylated, we propose that acetylation is a major posttranslational modifier that regulates cellular metabolism.

Benefits associated with a broad selection of dosage strengths for recombinant factor VIII products

Factor VIII (FVIII) concentrates for haemophilia A patients are dosed according to body weight. This results in a continuous range of prescribed doses, which challenges pharmacies to find dosage strengths closest to the prescribed dose while utilizing the least number of vials. This study was conducted to determine whether a broader selection of FVIII dosage strengths results in improved dispensing accuracy and an increased number of single-vial users. This research retrospectively analyzed a US pharmacy database of prescriptions filled in 2008. Recombinant FVIII (rFVIII) therapies were classified by the range of dosage strengths offered in 2008: Group 1 had three dosage strengths; Group 2 had four dosage strengths; and Group 3 had six dosage strengths. A total of 76,584 dispensed doses of rFVIII for 1,244 patients were included in this analysis. Dispensing accuracy (calculated as both the absolute and relative difference between dispensed and prescribed dose) was significantly better for Group 3 (23.2 IU, 1.2%) than Groups 1 (33.5 IU, 1.6%) and 2 (50.2 IU, 2.4%) (both P < 0.01). In addition, the average number of unique actual rFVIII potencies dispensed per month was highly correlated (-0.977) with dispensing accuracy for each dosage strength group. Among Groups 1, 2 and 3, 23.0%, 44.9% and 73.4% of patients, respectively, had at least one single vial option dispensed (P < 0.0001). A broader selection of rFVIII dosage strengths and more actual rFVIII potencies were associated with improved dispensing accuracy and more single-vial users. This may translate into less waste, cost savings, increased convenience and improved adherence to physician-prescribed regimens.