In-vivo Exposure Research Articles

Guadecitabine (SGI-110) in patients with intermediate or high-risk myelodysplastic syndromes: phase 2 results from a multicentre, open-label, randomised, phase 1/2 trial

Guadecitabine is a next-generation hypomethylating agent whose active metabolite decitabine has a longer in-vivo exposure time than intravenous decitabine. More effective hypomethylating agents are needed for the treatment of myelodysplastic syndromes. In the present study, we aimed to compare the activity and safety of two doses of guadecitabine in hypomethylating agent treatment-naive or relapsed or refractory patients with intermediate-risk or high-risk myelodysplastic syndromes. This phase 2 part of the phase 1/2, randomised, open-label study enrolled patients aged 18 years or older from 14 North American medical centres with International Prognostic Scoring System intermediate-1-risk, intermediate-2-risk, or high-risk myelodysplastic syndromes, or chronic myelomonocytic leukaemia. They were either hypomethylating agent treatment-naive or had relapsed or refractory disease after previous hypomethylating agent treatment as determined by the investigators' judgment. Eligible patients had Eastern Cooperative Oncology Group performance status of 0-2. Patients were randomly assigned (1:1) using a computer algorithm for dynamic randomisation to subcutaneous guadecitabine 60 or 90 mg/m2 on days 1-5 of a 28-day treatment cycle. Treatment was stratified by previous treatment with hypomethylating agents and neither patients nor investigators were masked. The primary endpoint was overall response (a composite of complete response, partial response, marrow complete response, and haematological improvement) assessed in all patients who received at least one dose of study drug. This study is registered with ClinicalTrials.gov, number NCT01261312. Between July 9, 2012, and April 7, 2014, 105 patients were enrolled: 55 (52%) were allocated to guadecitabine 60 mg/m2 (28 patients were treatment-naive and 27 had relapsed or refractory disease after previous hypomethylating agent treatment) and 50 (48%) patients to 90 mg/m2 (23 patients were treatment-naive and 27 had relapsed or refractory disease). Three (3%) patients of 105 did not receive study treatment and were excluded from analyses. Median follow-up was 3·2 years (IQR 2·8-3·5). The proportion of patients achieving an overall response did not significantly differ between dose groups (21 of 53 [40%, 95% CI 27-54] with 60 mg/m2 and 27 of 49 [55%, 95% CI 40-69] with 90 mg/m2; p=0·16). 25 of 49 (51%, 95% CI 36-66) patients who were treatment-naive and 23 of 53 (43%, 30-58) patients with relapsed or refractory disease achieved an overall response. The most common grade 3 or worse adverse events in both groups, regardless of relationship to treatment, were thrombocytopenia (22 [41%] of 53 patients in the 60 mg/m2 group and 28 [57%] of 49 in the 90 mg/m2 group), neutropaenia (21 [40%] and 25 [51%]), anaemia (25 [47%] and 24 [49%]), febrile neutropaenia (17 [32%] and 21 [43%]), and pneumonia (13 [25%] and 15 [31%]). Seven (7%) of 102 patients died due to adverse events (three with 90 mg/m2 and four with 60 mg/m2), and all except one were in the relapsed or refractory cohort. Two deaths were deemed treatment related (septic shock with 60 mg/m2; pneumonia with 90 mg/m2). Guadecitabine was clinically active with acceptable tolerability in patients with intermediate-risk and high-risk myelodysplastic syndromes. Responses and overall survival in the relapsed or refractory cohort offer the potential of a new therapeutic option for patients for whom currently available hypomethylating agents are not successful. We therefore recommend guadecitabine at a dose of 60 mg/m2 on a 5-day schedule for these patients. Astex Pharmaceuticals and Stand Up To Cancer.

Automated virtual reality exposure therapy for spider phobia vs. in-vivo one-session treatment: A randomized non-inferiority trial

ObjectiveThis study compared the efficacy of a technician-assisted single-session virtual reality exposure therapy (VRET) for the treatment of spider phobia featuring low-cost consumer-available hardware and novel automated software to gold-standard in-vivo one-session treatment (OST), using a parallel group randomized non-inferiority design. Method Participants (N = 100) were randomized to VRET and OST arms. Assessors blinded to treatment allocation evaluated participants at pre- and post-treatment as well follow-up (3 and 12 months) using a behavioral approach test (BAT) and self-rated fear of spider, anxiety, depression and quality-of-life scales. A maximum post-treatment difference of 2-points on the BAT qualified as non-inferiority margin. Results Linear mixed models noted large, significant reductions in behavioral avoidance and self-reported fear in both groups at post-treatment, with VRET approaching the strong treatment benefits of OST over time. Non-inferiority was identified at 3- and 12- months follow-up but was significantly worse until 12-months. There was no significant difference on a questionnaire measuring negative effects. Conclusions Automated VRET efficaciously reduced spider phobia symptoms in the short-term and was non-inferior to in-vivo exposure therapy in the long-term. VRET effectiveness trials are warranted to evaluate real-world benefits and non-specific therapeutic factors accruing from the presence of a technician during treatment. ClinicalTrials.gov (NCT02533310).

Heart rate variability in patients with agoraphobia with or without panic disorder remains stable during CBT but increases following in-vivo exposure

Patients with anxiety disorders have a lower heart rate variability (HRV) than healthy controls. Low HRV is associated with cardiovascular disease and dysfunction of the autonomic nervous system (ANS). The aim of the present study was to investigate if HRV in patients with agoraphobia with or without panic disorder can be influenced by cognitive behavioral therapy (CBT). 73 patients with agoraphobia with or without panic disorder were included in the study. Heart rate (HR) and HRV were recorded at rest before and after CBT and during in-vivo exposure. No changes in HR and HRV were observed throughout therapy. During in-vivo exposure HRV increased significantly and HR exhibited a tendency to decrease. Despite clinical improvement of anxiety symptoms, ANS activity at rest did not seem to be influenced by CBT. However, during in-vivo exposure, HRV changed significantly, indicating a higher parasympathetic activity at the end of exposure.

Biopsychosocial Rehabilitation Treatment "Exposure In Vivo" for Patients with Painful Diabetic Neuropathy: Development of a Treatment Protocol.

ObjectivePainful diabetic neuropathy is associated with low quality of life, depression and anxiety. Patients are limited in their performance of activities of daily living due to fears related to their condition. Treatment modalities are needed to help patients cope with their pain and pain-related disability. Exposure in vivo is an effective treatment in other chronic pain syndromes, increasing patients’ functional ability and quality of life. This paper presents an Exposure in vivo treatment protocol for patients with painful diabetic neuropathy.ProtocolAn 8-week Exposure in vivo treatment protocol was specifically adapted to the needs and risks of patients with painful diabetic neuropathy. New screening tools were developed for patients with PDN; the Painful Diabetic Neuropathy Anxiety Rasch-Transformed Questionnaire (PART-Q30) identifies specific fears related to painful diabetic neuropathy (e.g. fear of hypoglycaemia); and a customized version of the Photograph-series Of Daily Activities (PHODA-PDN) detects fear-eliciting activities related to the condition in individual patients. During Exposure in vivo, catastrophic interpretations regarding painful stimuli are challenged and corrected, thereby diminishing pain-related fear and enabling the patient to re-engage in activities of daily living. An interdisciplinary team provides Exposure in vivo in 1-h sessions twice a week.DiscussionTo the best of our knowledge, this treatment protocol is the first intervention using Exposure in vivo specifically adapted to the needs and risks of patients with painful diabetic neuropathy.LAY ABSTRACTPainful diabetic neuropathy is associated with low quality of life, depression and anxiety. Treatment modalities are needed to help patients cope with their pain and pain-related disability. Exposure in vivo is an 8-week biopsychosocial rehabilitation treatment that aims to restore a normal pattern of daily functioning. During Exposure in vivo, catastrophic interpretations regarding painful stimuli are challenged and corrected, thereby diminishing pain-related fear and enabling patients to re-engage in activities of daily living. An interdisciplinary team provides Exposure in vivo in 1-h sessions twice a week. Current Exposure in vivo treatments are designed for chronic pain conditions that generally have no medical risks or restrictions regarding physical activity. To the best of our knowledge, this treatment protocol is the first Exposure in vivo intervention specifically adapted to the needs and risks of patients with painful diabetic neuropathy. New screening tools were also designed for patients with painful diabetic neuropathy.

What is so frightening about spiders? Self-rated and self-disclosed impact of different characteristics and associations with phobia symptoms.

Spider phobia is a common and impairing mental disorder, yet little is known about what characteristics of spiders that spider phobic individuals find frightening. Using screening data from a clinical trial, we explored which characteristics that spider-fearful individuals (n=194) rated as having the greatest impact on fear, used factor analysis to group specific characteristics, and explored linear associations with self-reported phobia symptoms. Second, a guided text-mining approach was used to extract the most common words in free-text responses to the question: "What is it about spiders that you find frightening?" Both analysis types suggested that movement-related characteristics of spiders were the most important, followed by appearance characteristics. There were, however, no linear associations with degree of phobia symptoms. Our findings reveal the importance of targeting movement-related fears in in-vivo exposure therapy for spider phobia and using realistically animated spider stimuli in computer-based experimental paradigms and clinical interventions such as Virtual Reality exposure therapy.

RIP1 Kinase Drives Macrophage-Mediated Adaptive Immune Tolerance in Pancreatic Cancer

Pancreatic ductal adenocarcinoma (PDA) is characterized by immune tolerance and immunotherapeutic resistance. We discovered upregulation of receptor-interacting serine/threonine protein kinase 1 (RIP1) in tumor-associated macrophages (TAMs) in PDA. To study its role in oncogenic progression, we developed a selective small-molecule RIP1 inhibitor with high invivo exposure. Targeting RIP1 reprogrammed TAMs toward an MHCIIhiTNFα+IFNγ+ immunogenic phenotype in a STAT1-dependent manner. RIP1 inhibition in TAMs resulted in cytotoxic Tcell activation and T helper cell differentiation toward a mixed Th1/Th17 phenotype, leading to tumor immunity in mice and in organotypic models of human PDA. Targeting RIP1 synergized with PD1-and inducible co-stimulator-based immunotherapies. Tumor-promoting effects of RIP1 were independent of its co-association with RIP3. Collectively, our work describes RIP1 as a checkpoint kinase governing tumor immunity.

Treatment of cocaine use disorder with dTMS and in-vivo exposure: Case report

Treatment of cocaine use disorder with dTMS and in-vivo exposure: Case report

Post-exposure cortisol administration does not augment the success of exposure therapy: A randomized placebo-controlled study

Cortisol administration prior to treatment can promote the efficacy of exposure-based treatments in specific phobia: cortisol has been proposed to reduce fear retrieval at the beginning of exposure and to enhance the acquisition and consolidation of corrective information learned during exposure. Whether cortisol exerts a beneficial therapeutic effect when given after exposure, e.g., by targeting the consolidation of new corrective information, has not been addressed so far to date. Here, we examined whether post-exposure cortisol administration promotes fear reduction and reduces return of fear following contextual change in specific phobia. Furthermore, the effect of cortisol on return of fear following contextual change (i.e., contextual renewal) was assessed. Patients with spider phobia (N = 43) were treated with a single session of in-vivo exposure, followed by cortisol administration (20 mg hydrocortisone) in a double-blind, placebo-controlled study design. Return of fear was assessed with behavioral approach tests (BATs) in the familiar therapy context (versus a novel unfamiliar context) at one-month and seven-month follow-up assessment. Exposure was effective in reducing fear from pre-treatment to post-treatment (i.e., 24 h after exposure) on fear-related behavioral (approach behavior during the BAT), psychophysiological (heart rate during the BAT) and subjective (fear during the BAT, spider-fear related questionnaires) measures of therapeutic outcome, with no add-on benefit of cortisol administration. Cortisol had no effect on contextual renewal at one-month follow-up. However, in a subsample (N = 21) that returned to the seven-month follow-up, an adverse effect of cortisol on fear renewal was found, with cortisol-treated patients showing an increase in subjective fear at the final approach distance of the BAT from post-treatment to seven-month follow-up. These and previous findings underline the importance of considering the exact timing of cortisol application when used as an add-on treatment for extinction-based psychotherapy: post-exposure cortisol administration does not seem to be effective, but might promote fear renewal at the subjective level.

Successful Treatment of Halitophobia with Cognitive Behavioural Therapy: A Case Study

Halitophobia is a condition characterized by an excessive preoccupation with the belief of having halitosis. Cognitive Behavioural Therapy (CBT) was successfully used to treat a man in his 20 s who presented with important anxiety, avoidance and safety behaviours, isolation, and depressed mood. Progressive in-vivo exposure to fearful situations with the systematic prevention of avoidance and safety behaviours resulted in a significant improvement in the patient’s anxiety and depression levels. This case suggests that CBT techniques, usually performed in anxiety disorders and in obsessive–compulsive disorder, can be adapted to halitophobia.

The Ubiquitin Ligase Adaptor NDFIP1 Selectively Enforces a CD8+ T Cell Tolerance Checkpoint to High-Dose Antigen

Escape from peripheral tolerance checkpoints that control cytotoxic CD8+ Tcells is important for cancer immunotherapy and autoimmunity, but pathways enforcing these checkpoints are mostly uncharted. We reveal that the HECT-type ubiquitin ligase activator, NDFIP1, enforces a cell-intrinsic CD8+ Tcell checkpoint that desensitizes TCR signaling during invivo exposure to high antigen levels. Ndfip1-deficient OT-I CD8+ Tcells responding to high exogenous tolerogenic antigen doses that normally induce anergy aberrantly expanded and differentiated into effector cells that could precipitate autoimmune diabetes in RIP-OVAhi mice. In contrast, NDFIP1 was dispensable for peripheral deletion to low-dose exogenous or pancreatic islet-derived antigen and had little impact upon effector responses to Listeria or acute LCMV infection. These data provide evidence that NDFIP1 mediates a CD8+ Tcell tolerance checkpoint, with a different mechanism to CD4+ Tcells, and indicates that CD8+ Tcell deletion and anergy are molecularly separable checkpoints.

Evaluation of an Intensive Outpatient Program for Combat Veterans With PTSD

ABSTRACTThere is an identified need within the Veterans Affairs (VA) Healthcare System to provide robust treatment for combat veterans with PTSD. Although empirically supported treatments for PTSD are available within the VA system, the dropout rate is high and many veterans remain symptomatic after treatment has ended, indicating a need for further treatment development. In addition, some veterans require a higher level of care over the course of treatment but a stay at a residential facility is often not feasible. The purpose of this article is to present a newly developed intensive outpatient program, designed to bridge the gap between inpatient and outpatient levels of care, for combat veterans with PTSD. The program provides intensive psychoeducation on PTSD and associated symptoms such as guilt, shame, moral injury and avoidance, skill building to cope with intensive emotions, and in-vivo exposure activities delivered in an intensive group format. Initial results indicate that it may be feasible to implement an intensive outpatient program within existing outpatient resources, and that doing so may help veterans reduce PTSD symptoms, increase social support, and enhance the quality of individual psychotherapy after completion of the program.

Training Aims to Improve PTSD Treatment Nationwide

Training Aims to Improve PTSD Treatment Nationwide

Prolonged Corrosion Stability of a Microchip Sensor Implant during In Vivo Exposure.

A microelectronic biosensor was subjected to in vivo exposure by implanting it in the vicinity of m. trapezii (Trapezius muscle) from cattle. The implant is intended for the continuous monitoring of glucose levels, and the study aimed at evaluating the biostability of exposed semiconductor surfaces. The sensor chip was a microelectromechanical system (MEMS) prepared using 0.25 µm complementary metal–oxide–semiconductor CMOS/BiCMOS technology. Sensing is based on the principle of affinity viscometry with a sensoric assay, which is separated by a semipermeable membrane from the tissue. Outer dimensions of the otherwise hermetically sealed biosensor system were 39 × 49 × 16 mm. The test system was implanted into cattle in a subcutaneous position without running it. After 17 months, the device was explanted and analyzed by comparing it with unexposed chips and systems. Investigations focused on the MEMS chip using SEM, TEM, and elemental analysis by EDX mapping. The sensor chip turned out to be uncorroded and no diminishing of the topmost passivation layer could be determined, which contrasts remarkably with previous results on CMOS biosensors. The negligible corrosive attack is understood to be a side effect of the semipermeable membrane separating the assay from the tissue. It is concluded that the separation has enabled a prolonged biostability of the chip, which will be of relevance for biosensor implants in general.

Correlating in Vitro Solubilization and Supersaturation Profiles with in Vivo Exposure for Lipid Based Formulations of the CETP Inhibitor CP-532,623

Lipid based formulations (LBFs) are a promising formulation strategy for many poorly water-soluble drugs and have been shown previously to enhance the oral exposure of CP-532,623, an oral cholesteryl ester transfer protein inhibitor. In the current study, an in vitro lipid digestion model was used to probe the relationship between drug solubilization and supersaturation on in vitro dispersion and digestion of LBF containing long chain (LC) lipids and drug absorption in vivo. After in vitro digestion of LBF based on LC lipids, the proportion of CP-532,623 maintained in the solubilized state in the aqueous phase of the digest was highest in formulations containing Kolliphor RH 40, and in most cases outperformed equivalent formulations based on MC lipids. Subsequent administration of the LC-LBFs to beagle dogs resulted in reasonable correlation between concentrations of CP-532,623 measured in the aqueous phase of the in vitro digest after 30 min digestion and in vivo exposure (AUC); however, the LC-LBFs required greater in vitro drug solubilization to elicit similar in vivo exposure when compared to previous studies with MC-LBF. Although post digestion solubilization was enhanced in LC-LBF compared to MC-LBF, equilibrium solubility studies of CP-532,623 in the aqueous phase isolated from blank lipid digestion experiments revealed that equilibrium solubility was also higher, and therefore supersaturation lower. A revised correlation based on supersaturation in the digest aqueous phase and drug absorption was therefore generated. A single, linear correlation was evident for both LC- and MC-LBF containing Kolliphor RH 40, but this did not extend to formulations based on other surfactants. The data suggest that solubilization and supersaturation are significant drivers of drug absorption in vivo, and that across formulations with similar formulation composition good correlation is evident between in vitro and in vivo measures. However, across dissimilar formulations, solubilization and supersaturation alone are not sufficient to explain drug exposure and other factors also likely play a role.

The effects of surface processing on in-vivo corrosion of Nitinol stents in a porcine model.

Nitinol is a commonly used material in the medical device industry. However, correlations between surface processing of nitinol and in-vivo corrosion has yet to be established. Elucidating the link between in-vivo corrosion and pre-clinical characterization can aid in improved prediction of clinical safety and performance of nitinol devices. We addressed this knowledge gap by fabricating nitinol stents to possess distinct surface properties and evaluating their corrosion susceptibility both in-vitro and after six months of in-vivo exposure. Relationships between stent processing, surface characterization, corrosion bench testing, and outcomes from explanted devices are discussed. These findings highlight the importance of surface characterization in nitinol devices and provide in-vitro pitting corrosion levels that can induce in-vivo corrosion in nitinol stents.

Janus kinase inhibitors prevent migration of rheumatoid arthritis neutrophils towards interleukin-8, but do not inhibit priming of the respiratory burst or reactive oxygen species production.

Neutrophils play a crucial role in the pathophysiology of rheumatoid arthritis (RA) via the release of reactive oxygen species (ROS), proteases and cytokines. Orally active Janus kinase (JAK) inhibitors (JAKi), e.g. baricitinib and tofacitinib, have high clinical efficacy in RA but are linked with neutropenia and increased infections. Our aim was to determine the effect of JAK inhibition with baricitinib and tofacitinib on healthy control and RA neutrophil lifespan and function. RA (n = 7) and healthy control (n = 7) neutrophils were treated with baricitinib or tofacitinib for 30 min, prior to incubation in the absence or presence of granulocyte-macrophage colony-stimulating factor (GM-CSF) or interferon (IFN)-γ. JAKi prevented GM-CSF- and IFN-γ-induced apoptosis delay in RA and healthy control neutrophils in a dose-dependent manner. Baricitinib decreased the rate of chemotaxis towards interleukin (IL)-8, but not f-Met-Leu-Phe (fMLP) in RA neutrophils. While healthy control neutrophils incubated with GM-CSF became primed to produce ROS in response to stimulation with fMLP and phorbol-12-myristate-12-acetate (PMA), RA neutrophils produced increased levels of ROS without the need for priming. JAKi prevented ROS release from primed healthy control neutrophils in response to fMLP, but had no effect on ROS production by RA neutrophils. Baricitinib reversed GM-CSF priming of ROS production in response to fMLP in healthy control, but not RA, neutrophils. We conclude that incubation with JAKi prevents chemotaxis of RA neutrophils towards IL-8, but does not prevent the production of ROS or increase the level of apoptosis. This may be due to the in-vivo exposure of RA neutrophils to priming agents other than those that activate JAK/signal transducer and activator of transcription (STAT) signalling.

RS9, a novel Nrf2 activator, attenuates light-induced death of cells of photoreceptor cells and Müller glia cells.

The retina is highly sensitive to oxidative stress because of its high consumption of oxygen associated with the phototransductional processes. Recent findings have suggested that oxidative stress is involved in the pathology of age-related macular degeneration, a progressive degeneration of the central retina. A well-known environmental risk factor is light exposure, as excessive and continuous light exposure can damage photoreceptors. Nuclear factor-erythroid 2-related factor 2 (Nrf2) is a transcriptional factor that controls antioxidative responses and phase 2 enzymes. Thus, we hypothesized that RS9, a specific activator of Nrf2, decreases light-induced retinal cell death invivo and invitro. Nrf2 was detected in the nucleus of the 661W cells exposed to RS9 and also after light exposure, and the Nrf2-antioxidant response element binding was increased in 661W cells after exposure to RS9. Consequentially, the expression of the phase 2 enzyme's mRNAs of Ho-1, Nqo-1, and Gclm genes was increased in 661W cells after exposure to RS9. Furthermore, RS9 decreased the light-induced death of 661W cells (2500lux, 24h), and also reduced the functional damages and the histological degeneration of the nuclei in the outer nuclear layer or the retina in the invivo studies (8000lux, 3h). Heme oxygenase-1 was increased after light exposure, and Nrf2 was translocated into the nucleus after light exposure invivo. Silencing of Ho-1 reduced the protective effects of RS9 against light-induced death of 661W cells. These findings indicate that RS9 has therapeutic potential for retinal diseases that are aggravated by light exposure.

A systematic review and meta-analysis of treatments for acrophobia.

To review the literature on the comparative efficacy of psychological, behavioural and medical therapies for acrophobia (fear of heights). Multiple databases were searched through the Cochrane Common Mental Disorders review group on 1 December 2015. The data were extracted independently and were pooled using RevMan version 5.3.5. The main outcome measures were changes from baseline on questionnaires for measurement of fear of heights, such as the Acrophobia Questionnaire (AQ), Attitude Towards Height Questionnaire (ATHQ), and behavioural avoidance tests. Individual and pooled analyses were conducted. Sixteen studies were included. Analysis of pooled outcomes showed that desensitisation (DS) measured by the post-test AQ anxiety score (standardised mean difference [SMD], -1.24; 95% CI, -1.88 to -0.60) and in vivo exposure (IVE) were effective in the short term compared with control (SMD, -0.74; 95% CI, -1.22 to -0.25). IVE was not effective in the long term (SMD, -0.34; 95%CI -0.76 to 0.08) and there were no follow-up data for DS. Virtual reality exposure (VRE) therapy was effective when assessed with the ATHQ but not the AQ. Augmentation of VRE with medication was promising. The number needed to treat (NNT) ranged from 1.4 (95% CI, 1.0 to 2.2) for IVE therapy with oppositional actions (a psychological process) versus waitlist control to an NNT of 6.0 (95% CI, 2.8 to 35.5) for the rapid phobia cure (a neurolinguistic programming technique) versus a mindfulness exercise as the control activity. It was often unclear if there were biases in the included studies. A range of therapies are effective for acrophobia in the short term but not in the long term. Many of the comparative studies showed equivalence between therapies, but this finding may be due to a type II statistical error. The quality of reporting was poor in most studies.

In Vivo Exposure to Inorganic Arsenic Alters Differentiation-Specific Gene Expression of Adipose-Derived Mesenchymal Stem/Stromal Cells in C57BL/6J Mouse Model.

The number of mesenchymal stem cell (MSC) therapeutic modalities has grown in recent years. Adipose-derived mesenchymal stem/stromal cells (ASCs) can be isolated and expanded relatively easily as compared with their bone-marrow counterparts, making them a particularly promising source of MSCs. And although the biological mechanisms surrounding ASCs are actively being investigated, little is known about the effects that in vivo environmental exposures might have on their ability to properly differentiate. Therefore, we hypothesized that ASCs isolated from mice exposed to inorganic arsenic (iAs) would have an altered response towards adipogenic, osteogenic, and/or chondrogenic differentiation. To test this hypothesis, C57BL/6J male mice were provided drinking water containing 0, 300, or 1000 ppb iAs. ASCs were then isolated and differentiated, which was assessed by immunocytochemistry and real-time quantitative PCR (RT-qPCR). Our results showed that total urinary arsenic equilibrated within 1 week of exposure to iAs and was maintained throughout the study. ASCs isolated from each exposure group maintained differentiation capabilities for each lineage. The magnitude of differentiation-specific gene expression, however, appeared to be concentration dependent. For osteogenesis and chondrogenesis, differentiation-specific gene expression decreased, whereas adipogenesis showed a biphasic response with an initial decrease followed by an increase in adipogenic-related gene expression following iAs exposure. These results suggest that the level in which differentiation-specific genes are induced within these stromal cells might be sensitive to environmental contaminants. These findings highlight the need to take into account potential environmental exposures prior to selecting stromal cell donors, so ASCs can achieve optimal efficiency in regenerative therapy applications.

Exposure to subthreshold dose of UVR-B induces apoptosis in the lens epithelial cells and does not in the lens cortical fibre cells.

The aim of this study was to investigate in which part of the lens invivo exposure to subthreshold dose of UVR-B radiation induces apoptosis. Twenty 6-week-old female albino Sprague-Dawley rats were exposed to subthreshold dose (1kJ/m2 ) of UVR-B unilaterally and killed at 120hr after exposure. Lenses were enucleated and dissected on three regions: the lens epithelium, the cortex and the nucleus. The lens nucleus then was removed. Apoptosis markers p53 and caspase 3 were used to study apoptosis in the lens regions. qRT-PCR and Western blot were utilized to analyse the lenses. TP53 and CASP3 mRNA expressions are increased in exposed lenses, both in the lens epithelium and in the cortex regions, in relation to non-exposed lenses. Expression of p53 protein is increased in exposed lens epithelium in relation to non-exposed lens epithelium. Caspase 3 protein is expressed in exposed lens epithelial cells, while it is not expressed in non-exposed lens epithelial cells. p53 and caspase 3 proteins are not expressed in either exposed nor non-exposed lens fibre cells. Exposure to UVR-B increases mRNA transcription of apoptosis marker p53 invivo in both regions of the lens and of apoptosis marker caspase 3 in the lens cortex. Exposure to UVR-B increases p53 and caspase 3 proteins expression just in the lens epithelium. In vivo exposure to subthreshold dose of UVR-B induces apoptosis in the lens epithelial cells and does not in the lens fibre cells.