Aggregation-prone c9FTD/ALS poly(GA) RAN-translated proteins cause neurotoxicity by inducing ER stress

The occurrence of repeat-associated non-ATG (RAN) translation, an atypical form of translation of expanded repeats that results in the synthesis of homopolymeric expansion proteins, is becoming more widely appreciated among microsatellite expansion disorders. Such disorders include amyotrophic lateral sclerosis and frontotemporal dementia caused by a hexanucleotide repeat expansion in the C9ORF72 gene (c9FTD/ALS). We and others have recently shown that this bidirectionally transcribed repeat is RAN translated, and the “c9RAN proteins” thusly produced form neuronal inclusions throughout the central nervous system of c9FTD/ALS patients. Nonetheless, the potential contribution of c9RAN proteins to disease pathogenesis remains poorly understood. In the present study, we demonstrate that poly(GA) c9RAN proteins are neurotoxic and may be implicated in the neurodegenerative processes of c9FTD/ALS. Specifically, we show that expression of poly(GA) proteins in cultured cells and primary neurons leads to the formation of soluble and insoluble high molecular weight species, as well as inclusions composed of filaments similar to those observed in c9FTD/ALS brain tissues. The expression of poly(GA) proteins is accompanied by caspase-3 activation, impaired neurite outgrowth, inhibition of proteasome activity, and evidence of endoplasmic reticulum (ER) stress. Of importance, ER stress inhibitors, salubrinal and TUDCA, provide protection against poly(GA)-induced toxicity. Taken together, our data provide compelling evidence towards establishing RAN translation as a pathogenic mechanism of c9FTD/ALS, and suggest that targeting the ER using small molecules may be a promising therapeutic approach for these devastating diseases.     

Sustained Dyskinesias Following Elective Cessation and Reactivation of Chronic Subthalamic Nucleus Deep Brain Stimulation for a Surgical Procedure

Objectives: Subthalamic nucleus deep brain stimulation (STN DBS) is effective for treatment of levodopa‐induced dyskinesias in patients with Parkinson's disease (PD). Medical or surgical procedures requiring electrocautery may require inactivation of the pulse generators to avoid damage to the lead or extension wire or possible reprogramming of the stimulators. This generally causes only mild and temporary disability. We report a patient with previously well‐controlled dyskinesias who had severe and prolonged dyskinesias following reactivation of deep brain stimulation (DBS) following an orthopedic procedure. Materials and Methods: Retrospective chart review. Results: The patient underwent two orthopedic procedures, each requiring inactivation of DBS. After reactivation of DBS, the patient experienced severe dyskinesias that ultimately required sedation and ventilation to control large‐amplitude dyskinesias. Conclusions: Clinicians caring for PD patients treated with STN DBS should be aware of the possible reappearance of severe dyskinesias arising from routine inactivation and reactivation of pulse generators for medical or surgical procedures.     

Recellularizing of human acellular dermal matrices imaged by high‐definition optical coherence tomography

High‐definition optical coherence tomography (HD‐OCT) permits real‐time 3D imaging of the impact of selected agents on human skin allografts. The real‐time 3D HD‐OCT assessment of (i) the impact on morphological and cellular characteristics of the processing of human acellular dermal matrices (HADMs) and (ii) repopulation of HADMs in vitro by human fibroblasts and remodelling of the extracellular matrix by these cells. Four different skin decellularization methods, Dispase II/Triton X‐100, Dispase II/SDS (sodium dodecyl sulphate), NaCl/Triton X‐100 and NaCl/SDS, were analysed by HD‐OCT. HD‐OCT features of epidermal removal, dermo‐epidermal junction (DEJ) integrity, cellularity and dermal architecture were correlated with reflectance confocal microscopy (RCM), histopathology and immunohistochemistry. Human adult dermal fibroblasts were in vitro seeded on the NaCl/Triton X‐100 processed HADMs, cultured up to 19 days and evaluated by HD‐OCT in comparison with MTT proliferation test and histology. Epidermis was effectively removed by all treatments. DEJ was best preserved after NaCl/Triton X‐100 treatment. Dispase II/SDS treatment seemed to remove all cellular debris in comparison with NaCl/Triton X‐100 but disturbed the DEJ severely. The dermal micro‐architectural structure and vascular spaces of (sub)papillary dermis were best preserved with the NaCl/Triton X‐100. The impact on the 3D structure and vascular holes was detrimental with Dispase II/SDS. Elastic fibre fragmentation was only observed after Dispase II incubation. HD‐OCT showed that NaCl/Triton X‐100 processed matrices permitted in vitro repopulation by human dermal fibroblasts (confirmed by MTT test and histology) and underwent remodelling upon increasing incubation time. Care must be taken in choosing the appropriate processing steps to maintain selected properties of the extracellular matrix in HADMs. Processing HADMs with NaCl/Triton X‐100 permits in vitro the proliferation and remodelling activity of human dermal fibroblasts. HD‐OCT provides unique real‐time and non‐invasive 3D imaging of tissue‐engineered skin constructs and complementary morphological and cytological information.     

Radiation-induced bullous pemphigoid: a systematic review of an unusual radiation side effect.

BACKGROUND: Percutaneous radiotherapy (RT) may cause a range of acute and late side effects of the skin within the irradiated area. In rare cases radiotherapy can cause bullous pemphigoid (BP). BP is reported to occur mainly within irradiated fields following radiation treatment. Exceptionally, BP may arise during RT. It is unclear which mechanism exactly triggers BP following megavoltage irradiation and whether there is a potential association with hormonal anticancer treatment. METHODS: A systematic literature based review was performed. Publications reporting histologically confirmed BP and a treatment with RT were retrieved based on a standardized query using electronic databases. A standardized quality assessment was applied. RESULTS: Out of 306 potentially relevant publications 21 were identified to be relevant and included in this review. An association between RT and BP was reported in 27 patients. The majority developed BP after RT and a median dose of 50 Gy. Four patients developed BP during RT after a minimal dose of 20 Gy. CONCLUSIONS: BP induced by RT was observed predominantly in patients with breast cancer. In all reported cases, there is a clear relationship with RT. Therefore, BP may be considered as RT-induced side effect. RT can induce a BP following a minimal dose of 20 Gy. New biological agents may play a role in the future treatment of BP.     

The heregulin/human epidermal growth factor receptor as a new growth factor system in melanoma with multiple ways of deregulation

In a screening for new growth factors released by melanoma cells, we found that the p185-phosphorylating capacity of a medium conditioned by a melanoma cell line was due to the secretion of heregulin, a ligand for the human epidermal growth factor receptor (HER) family of receptor tyrosine kinases. Expression of heregulin, including a new isoform, and secretion of functionally active protein was found in several cell lines. Receptor activation by heregulin, either autocrine or paracrine, resulted in a potent growth stimulation of both melanocytes and melanoma cells. Heregulin receptor HER3 and coreceptor HER2 were the main receptors expressed by these cells. Nevertheless, none of the cell lines in our panel overexpressed HER2 or HER3. In contrast, loss of HER3 was found in two cell lines, whereas one cell line showed loss of functional HER2, both types of deregulations resulting in unresponsiveness to heregulin. This implies the heregulin/HER system as a possible important physiologic growth regulatory system in melanocytes in which multiple deregulations may occur during progression toward melanoma, all resulting in, or indicating, growth factor independence.     

Current strategies in the treatment of childhood Hodgkins disease

Dramatic changes in the treatment of childhood Hodgkins disease have taken place during the past three decades. Contemporary combined modality treatment regimens produce durable disease-free survival in 90 to 100%of patients with early disease and in 70 to 85%of patients with advanced disease. Studies using chemotherapy alone also report high survival rates, and current studies are few to highlight the superiority of chemo-radiotherapy vs. chemotherapy alone. After the prodigious improvement achieved in response and survival rates, current strategies aim at reducing late effects of therapy, reserving more aggressive treatment modalities for patients with high risk features.     

Heterogeneity of anti-beta2-glycoprotein I antibodies. A factor of variability in test results

The aim of this study was to evaluate the heterogeneity of IgGanti-beta2-glycoprotein I antibodies (IgG-abeta2GPI) as regarding their reactivity pattern against different sources of human beta2 GPI, their avidity and their association with clinical events of antiphospholipid syndrome (APS). Three thousand six hundred and eighty-four consecutive patient sera were routinely tested for IgGabeta2 GPI over 1 year using an in-house ELISA with 2 different commercial preparations of human purified beta2GPI. Of the 340 sera found positive, all those clinically documented were included in this study; 61 were positive with only one preparation (S1) and 59 with both (S2). The results of ELISA were confirmed by Western blot. Heterogeneity was stressed by testing sera with a human recombinant protein and 3 beta2GPI-related peptides. No contribution of glycosylation in the binding to beta2GPI was found. The avidity indices for each protein were significantly higher in S1 than in S2 (p=0.0021). S2 were more associated with antiphospholipid antibodies than S1 (75% versus 21% ; p<0.0001). A similar frequency of the main clinical features of APS was found in S1 and S2 sera (69% and 71%, respectively). In conclusion, our data show a heterogeneity in the antigenic reactivity pattern of IgG- abeta2 GPI and a relationship between a binding profile and antibody avidity. This heterogeneity could represent a crucial factor of variability in test results and underlines the difficulty of getting standardisation.