Influence of VEGF/BMP-2 on the proliferation and osteogenetic differentiation of rat bone mesenchymal stem cells on PLGA/gelatin composite scaffold

OBJECTIVE

To investigate the influence of VEGF/BMP-2 on the proliferation and osteogenic differentiation of rat bone mesenchymal stem cells BMSCs) on PLGA/gelatin composite scaffold.

MATERIALS AND METHODS

Randomly-oriented nanofibers with different ratios of Poly Lactic-co-Glycolic Acid (PLGA)/gelatin were produced through electrospinning. The mixture of nanofibers and BMSCs was pipetted onto the surface of the scaffolds, and BMSCs/PLGA/gelatin composite was obtained. The surface morphology, chemical structure, hydrophilicity and mechanical property of PLGA/gelatin nanofibers were revealed by scanning electron microscope. In vitro release kinetics of bone morphogenetic protein (BMP-2) and vascular endothelial growth factor (VEGF) were studied using ELISA kits. The cell adhesion, growth and proliferation of BMSCs on scaffolds were observed by scanning electron microscopy. The CCK-8 assay was used to evaluate the effects of VEGF/BMP-2 slow release system on the proliferation of BMSCs on scaffolds. RT-PCR was used to examine the activities of alkaline phosphatase (ALP), runt-related transcription factor 2 (RUNX-2), and osteocalcin (OCN).

RESULTS

In each group of cells in the in-vitro experiment, through electron microscope scanning, fiber scaffolds were interconnected three-dimensional reticular structure, BMSCs firmly attached to the fiber surface and internal stent, cells experienced a long spindle, polygon change, and branch-like protrusions on the cell surface were connected. Under the electron microscope, cell proliferation curve and osteogenesis markers (ALP, RUNX-2, OCN) expression in the dual factor group on cell adhesion, proliferation and differentiation were much better than those of blank control group and single factor groups.

CONCLUSIONS

In the successfully constructed gelatin/PLGA nanofiber scaffold, VEGF and BMP-2 can be sequentially released, during which VEGF and BMP-2 can promote the adhesion, proliferation, and differentiation of BMSCs.

NF-κB/P65 signaling pathway: a potential therapeutic target in postoperative cognitive dysfunction after sevoflurane anesthesia

OBJECTIVE

This study aimed to explore the role of NF-κB/P65 signaling pathway in postoperative cognitive dysfunction (POCD) after sevoflurane anesthesia.

MATERIALS AND METHODS

A total of 120 male Sprague-Dawley (SD) rats were selected and assigned into five groups (24 rats in each group): the control, sevoflurane, sevoflurane + splenectomy, pyrrolidine dithiocarbamate (PDTC, a specific inhibitor of NF-κB), and sevoflurane + splenectomy + PDTC groups. Electrocardiogram (ECoG) and behavior changes of rats were monitored before and after anesthesia/operation. Ionized calcium-binding adapter molecules 1 (Iba-1) in the hippocampal zones were observed by immunofluorescence staining. Blood-brain barrier (BBB) permeability was determined by immunohistochemistry. The mRNA and protein expressions of NF-κB/P65 signaling pathway-related proteins and inflammatory cytokines were detected by qRT-PCR assay and Western blotting.

RESULTS

During the anesthesia/operation, the vital signs of rats were stable, but the ECoG in the sevoflurane and sevoflurane + splenectomy groups mainly presented slow waves. The ECoG arousal response in the sevoflurane + splenectomy + PDTC group was observed. At 24 h after the anesthesia/operation, the expressions of NF-κB and P65 in the hippocampal zone, the expressions of IκBα and inflammatory cytokines (IL-1β, IL-6 and TNF-α), the expression of Iba-1 in rat hippocampal dentate gyrus (DG) zone and CA3 zone, and the permeability of BBB were significantly increased and the behavior of rats changed dramatically (all p < 0.05), while PDTC treatments could eliminate these changes induced by the anesthesia/operation (all p < 0.05). No changes were observed in the expressions of NF-κB, P65, IκBα, Iba-1 and inflammatory cytokines (IL-1β, IL-6 and TNF-α), and the permeability of BBB and the behavior of rats in the sevoflurane and the PDTC groups (all p > 0.05).

CONCLUSIONS

These results suggest that the inhibition of NF-κB/P65 signaling pathway may relieve POCD after sevoflurane anesthesia.

Impacts of interfacial charge transfer on nanoparticle electrocatalytic activity towards oxygen reduction

Interfacial electron transfer within platinum and non-platinum-based nanocatalysts plays a significant role in the manipulation of the electronic interactions between oxygen species and the catalyst surfaces, which may be exploited as an effective mechanism to enhance and optimize the activity towards oxygen reduction.

CD39 overexpression does not attenuate renal fibrosis in the unilateral ureteric obstructive model of chronic kidney disease

Chronic kidney disease has multiple etiologies, but its single, hallmark lesion is renal fibrosis. CD39 is a key purinergic enzyme in the hydrolysis of ATP and increased CD39 activity on regulatory T cells (Treg) is protective in adriamycin-induced renal fibrosis. We examined the effect of overexpression of human CD39 on the development of renal fibrosis in the unilateral ureteric obstructive (UUO) model, a model widely used to study the molecular and cellular factors involved in renal fibrosis. Mice overexpressing human CD39 (CD39Tg) and their wild-type (WT) littermates were subjected to UUO; renal histology and messenger RNA (mRNA) levels of adenosine receptors and markers of renal fibrosis were examined up to 14 days after UUO. There were no differences between CD39Tg mice and WT mice in the development of renal fibrosis at days 3, 7, and 14 of UUO. Relative mRNA expression of the adenosine A_2A receptor and endothelin-1 were higher in CD39Tg than WT mice at day 7 post UUO, but there were no differences in markers of fibrosis. We conclude that human CD39 overexpression does not attenuate the development of renal fibrosis in the UUO model. The lack of protection by CD39 overexpression in the UUO model is multifactorial due to the different effects of adenosinergic receptors on the development of renal fibrosis.

The Use of Gene Therapy in Cancer Research and Treatment

Gene therapy involves identifying a gene of interest and then manipulating the expression of this gene through a variety of techniques. Here we specifically address gene therapy's role in cancer research. This paper will encompass thoroughly investigated techniques such as cancer vaccines and suicide gene therapy and the latest advancements in and applications of these techniques. It will also cover newer techniques such as Antisense Oligonucleotides and small interfering RNAs and how these technologies are being developed and used. The use of gene therapy continues to expand in cancer research and has an integral role in the advancement of cancer treatment.

BDNF pro-peptide regulates dendritic spines via caspase-3

The precursor of brain-derived neurotrophic factor (BDNF) (proBDNF) is enzymatically cleaved, by either intracellular (furin/PC1) or extracellular proteases (tPA/plasmin/MMP), to generate mature BDNF (mBDNF) and its pro-peptide (BDNF pro-peptide). Little is known about the function of BDNF pro-peptide. We have developed an antibody that specifically detects cleaved BDNF pro-peptide, but not proBDNF or mBDNF. Neuronal depolarization elicited a marked increase in extracellular BDNF pro-peptide, suggesting activity-dependent regulation of its extracellular levels. Exposure of BDNF pro-peptide to mature hippocampal neurons in culture dramatically reduced dendritic spine density. This effect was mediated by caspase-3, as revealed by studies with pharmacological inhibitors and genetic knockdown. BDNF pro-peptide also increased the number of ‘elongated' mitochondria and cytosolic cytochrome c, suggesting the involvement of mitochondrial-caspase-3 pathway. These results, along with BDNF pro-peptide effects recently reported on growth cones and long-term depression (LTD), suggest that BDNF pro-peptide is a negative regulator of neuronal structure and function.

Clinical research about airway pressure release ventilation for moderate to severe acute respiratory distress syndrome

OBJECTIVE

To evaluate clinical effects of airway pressure release ventilation (APRV) in patients suffering from moderate to severe acute respiratory distress syndrome (ARDS).e of a patient presented with significant high aminotransferase levels due to the first human R. aeschlimannii infection ever detected in Italy. The hypothesis of rickettsiosis was made on the basis of a comprehensive medical history and was confirmed by serological tests. Molecular analyses made on a sample of hepatic tissue revealed the presence of a rickettsial species never found before in human liver.

PATIENTS AND METHODS

From August 2012 to August 2014, fifty-two cases with moderate to severe ARDS were randomly divided into two groups. In the first group (APRV) the airway pressure release ventilation was used; the second group (SIMV) was ventilated using synchronized intermittent mandatory ventilation mode and positive end expiratory pressure (PEEP). Changes in oxygenation index, respiratory mechanics, extravascular lung water, functional residual capacity change and hemodynamics were recorded in both groups after mechanical ventilation. TNF-a and IL-10 levels in alveolar lavage were also measured. Acute physiology and chronic health evaluation (APACHE) II and Murray scores were evaluated. Pneumothorax and mediastinal emphysema during ventilation were also recorded. The probability of survival, the duration of ICU stay, days without organ failure and days without sedation were compared.

RESULTS

Conditions in APRV were improved significantly. Oxygenation index was increased, airway peak pressure (Ppeak) was reduced, the lung dynamic compliance improved, extravascular lung water was relieved, functional residual capacity increased and Murray score was improved. In APRV group ventilation central venous pressure (CVP) and systemic circulation resistance index (SVRI) were reduced, but cardiac index (CI) increased, and at the same time lac and oxygen saturation of central venous blood (ScvO2) were improved. Free sedatives days were significantly reduced in APRV group while days without mechanical ventilation were increased and days in ICU were shortened significantly. TNF-α and IL-10 concentrations in the alveolar lavage, probability of survival and days without organ failure were similar in both groups.

CONCLUSIONS

In patients suffering from moderate to severe ARDS, application of APRV improved lung function and hemodynamics. It also reduced the need for sedatives and the duration of mechanical ventilation as well as days in ICU.

Positron emission tomography response evaluation from a randomized phase III trial of weekly nab-paclitaxel plus gemcitabine versus gemcitabine alone for patients with metastatic adenocarcinoma of the pancreas

BACKGROUND

In the phase III MPACT trial, nab-paclitaxel plus gemcitabine (nab-P + Gem) demonstrated superior efficacy versus Gem alone for patients with metastatic pancreatic cancer. We sought to examine the feasibility of positron emission tomography (PET) and to compare metabolic response rates and associated correlations with efficacy in the MPACT trial.

PATIENTS AND METHODS

Patients with previously untreated metastatic adenocarcinoma of the pancreas were randomized 1:1 to receive nab-P + Gem or Gem alone. Treatment continued until disease progression by RECIST or unacceptable toxicity.

RESULTS

PET scans were carried out on the first 257 patients enrolled at PET-equipped centers (PET cohort). Most patients (252 of 257) had ≥2 PET-avid lesions, and median maximum standardized uptake values at baseline were 4.6 and 4.5 in the nab-P + Gem and Gem-alone arms, respectively. In a pooled treatment arm analysis, a metabolic response by PET (best response at any time during study) was associated with longer overall survival (OS) (median 11.3 versus 6.9 months; HR, 0.56; P < 0.001). Efficacy results within each treatment arm appeared better for patients with a metabolic response. The metabolic response rate (best response and week 8 response) was higher for nab-P + Gem (best response: 72% versus 53%, P = 0.002; week 8: 67% versus 51%; P = 0.014). Efficacy in the PET cohort was greater for nab-P + Gem versus Gem alone, including for OS (median 10.5 versus 8.4 months; hazard ratio [HR], 0.71; P = 0.009) and ORR by RECIST (31% versus 11%; P < 0.001).

CONCLUSION

Pancreatic lesions were PET avid at baseline, and the rate of metabolic response was significantly higher for nab-P + Gem versus Gem alone at week 8 and for best response during study. Having a metabolic response was associated with longer survival, and more patients experienced a metabolic response than a RECIST-defined response.

CLINICALTRIALSGOV

NCT00844649.