A SELECTIVE ER-PHAGY EXERTS PROCOLLAGEN QUALITY CONTROL VIA A CALNEXIN-FAM134B COMPLEX

The endoplasmic reticulum (ER) is the largest cellular organelle adapting dynamically to cope with cellular stress and high demand of newly synthesized proteins. Protein misfolding eventually occurs in the ER and leads to protein aggregation and ER dysfunction. Mammals have developed evolutionary-conserved quality control mechanisms at the ER. ER-phagy is a novel identified pathway targeting ER portions via autophagy for lysosomal degradation. This process occurs through ER-phagy receptors, ER proteins that bind autophagosomal LC3 protein via a cytosolic LC3 interacting domain. However, the importance of ER-phagy in maintaining cellular homeostasis is still undiscovered. Moreover, the molecular mechanisms that regulate ER-phagy according to cellular needs are still largely unknown. Chondrocytes and osteoblasts are highly secretory cells with an abundant ER, producing predominantly procollagen (PC) molecules in the extracellular matrix during endochondral ossification. They reside in a poorly vascularized tissue as the growth plate with scarcity of nutrients, representing a good cellular model to study ER-phagy. We have characterized ER- phagy in PC producing cells, serving as a cellular pathway that selectively recognizes misfolded PC in the ER lumen. Specifically we found that the ER chaperone CALNEXIN acts as co-receptor that recognizes ER-luminal misfolded PC and interacts with the ER- phagy receptor FAM134B. In turn, FAM134B binds the autophagosome membrane- associated protein LC3 and delivers a portion of ER containing both CALNEXIN and PC to the lysosome for degradation. Moreover, we identified ER-phagy as a transcriptionally induced mechanism by induction of FAM134B expression during starvation and upon FGF signaling, a critical regulator of chondrocyte differentiation. In vivo, FAM134B knock-down in Medaka fish dampened cartilage growth and bone formation, suggesting a physiological function of ER-phagy during skeletogenesis. Taken together, these data unveil a role for FAM134B-dependent ER-phagy in maintaining cellular fitness in PC producing cells and suggest potential therapeutic approaches for the treatment of skeletal features in multiple human diseases

Accidental neck and chest penetration by a metal sliver derived from an axe for wood chopping: A case report

Background: Penetrating neck and chest trauma is a very common entity in emergency medicine that usually requires surgical treatment. Our case report illustrates the case of a 27-year-old Arabian man with hemopneumothorax associated with pneumomediastinum due to an unusual occupational injury. Case presentation: A metal sliver, coming from an axe using for wood chopping, penetrated the neck of a 27-year-old Arabian man in the left supraclavicular region mimicking a gun bullet; the entrance hole was at the left pleural dome where the sliver had just penetrated the apex of the lung passing through the upper lobe of his left lung creating an exit wound in the dorsal segment of the same lobe arriving in the posterior thoracic wall. Biportal video-assisted thoracic surgery was performed to remove blood clots and the unusual foreign body. Conclusion: In the literature, there are several case series about this topic, with some of them reporting unusual foreign bodies that lead to penetrating trauma. However, to the best of our knowledge, no cases like the one we have reported are described in the current literature

AAV-mediated transcription factor EB (TFEB) gene delivery ameliorates muscle pathology and function in the murine model of Pompe Disease

Pompe disease (PD) is a metabolic myopathy due to acid alpha-glucosidase deficiency and characterized by extensive glycogen storage and impaired autophagy. We previously showed that modulation of autophagy and lysosomal exocytosis by overexpression of the transcription factor EB (TFEB) gene was effective in improving muscle pathology in PD mice injected intramuscularly with an AAV-TFEB vector. Here we have evaluated the effects of TFEB systemic delivery on muscle pathology and on functional performance, a primary measure of efficacy in a disorder like PD. We treated 1-month-old PD mice with an AAV2.9-MCK-TFEB vector. An animal cohort was analyzed at 3 months for muscle and heart pathology. A second cohort was followed at different timepoints for functional analysis. In muscles from TFEB-treated mice we observed reduced PAS staining and improved ultrastructure, with reduced number and increased translucency of lysosomes, while total glycogen content remained unchanged. We also observed statistically significant improvements in rotarod performance in treated animals compared to AAV2.9-MCK-eGFP-treated mice at 5 and 8 months. Cardiac echography showed significant reduction in left-ventricular diameters. These results show that TFEB overexpression and modulation of autophagy result in improvements of muscle pathology and of functional performance in the PD murine model, with delayed disease progression

Gene expression signatures predict response to therapy with growth hormone

Xarxes reguladores de gens; Marcadors predictiusRedes reguladoras de genes; Marcadores predictivosGene regulatory networks; Predictive markersRecombinant human growth hormone (r-hGH) is used as a therapeutic agent for disorders of growth including growth hormone deficiency (GHD) and Turner syndrome (TS). Treatment is costly and current methods to model response are inexact. GHD (n = 71) and TS patients (n = 43) were recruited to study response to r-hGH over 5 years. Analysis was performed using 1219 genetic markers and baseline (pre-treatment) blood transcriptome. Random forest was used to determine predictive value of transcriptomic data associated with growth response. No genetic marker passed the stringency criteria for prediction. However, we identified an identical set of genes in both GHD and TS whose expression could be used to classify therapeutic response to r-hGH with a high accuracy (AUC > 0.9). Combining transcriptomic markers with clinical phenotype was shown to significantly reduce predictive error. This work could be translated into a single genomic test linked to a prediction algorithm to improve clinical management. Trial registration numbers: NCT00256126 and NCT00699855.This work was supported by Merck KGaA, Darmstadt, Germany

Area-specific temporal control of corticospinal motor neuron differentiation by COUP-TFI

Transcription factors with gradients of expression in neocortical progenitors give rise to distinct motor and sensory cortical areas by controlling the area-specific differentiation of distinct neuronal subtypes. However, the molecular mechanisms underlying this area-restricted control are still unclear. Here, we show that COUP-TFI controls the timing of birth and specification of corticospinal motor neurons (CSMN) in somatosensory cortex via repression of a CSMN differentiation program. Loss of COUP-TFI function causes an area-specific premature generation of neurons with cardinal features of CSMN, which project to subcerebral structures, including the spinal cord. Concurrently, genuine CSMN differentiate imprecisely and do not project beyond the pons, together resulting in impaired skilled motor function in adult mice with cortical COUP-TFI loss-of-function. Our findings indicate that COUP-TFI exerts critical areal and temporal control over the precise differentiation of CSMN during corticogenesis, thereby enabling the area-specific functional features of motor and sensory areas to arise.Stem Cell and Regenerative Biolog

Robotic-assisted thoracoscopy thymectomy for juvenile myasthenia gravis

Abstract Introduction Juvenile myasthenia gravis (JMG) is a rare debilitating and potentially fatal autoimmune disease, with unclearify pathogenesis. Surgical immunomodulation with thymectomy has been repeatedly demonstrated to be a safe and effective treatment for JMG in both adult and pediatric patients. In the last few years, minimally invasive approach and above all robotic assisted thoracoscopy, replaced sternotomy which is widely used in adult patients. We report our experience in a case of robot-assisted thoracoscopic thymectomy approach in a 12 years old boy for juvenile myasthenia gravis (JMG). Case report Procedure was performed with the Da Vinci surgical robot (Xi) using left-sided approach. Left lung was kept out from mechanic ventilation. A 8 mm port for the 3-D camera was introduced on the V intercostal space on the anterior axillary line. Others two 8mm thoracic ports were placed under vision after the induction of a low-pressure pneumothorax, respectively on the midaxillary line on the III intercostal space and on the parasternal space on the V intercostal space. Bulk resection of gland was made using Maryland grasper and Harmonic scalpel, starting at level of the left pericardiophrenic angle and continuing cranially. Thymus was unstick from the posterior face of the sternum until the right pleura releasing lower thymic horns. After that, controlateral right-side thymectomy was continued into the neck to include the upper horns and finally it was removed with an endocatch bag. Histopathological examination showed a benign thymic hyperplasia. There were no perioperative and postoperative complications. The discharge was on IV post-operative day. After thymectomy, patient reported an improvement in symptoms and stopped medical therapy with pyridostigmine. Conclusions VATS and Robotic thoracoscopic thymectomy have increasingly taken hold in recent years. The surgical treatment offered to patient an improvement in clinical status. Surgery by robotic assistance has demonstrable advantages, including three-dimensional visualization and articulating instruments. Left lateral approach provided excellent visualization of the thymic veins, anonymous vases and phrenic nerves. Three-dimensional visualization as well as articulating arms greatly facilitated the dissection compared with standard thoracoscopic technique. In Literature very few series of robotic approach for surgical treatment of JMG in children are reported, for these reasons further studies are needed

Lysosomal dysfunction disrupts presynaptic maintenance and restoration of presynaptic function prevents neurodegeneration in lysosomal storage diseases

Lysosomal storage disorders (LSDs) are inherited diseases characterized by lysosomal dysfunction and often showing a neurodegenerative course. There is no cure to treat the central nervous system in LSDs. Moreover, the mechanisms driving neuronal degeneration in these pathological conditions remain largely unknown. By studying mouse models of LSDs, we found that neurodegeneration develops progressively with profound alterations in presynaptic structure and function. In these models, impaired lysosomal activity causes massive perikaryal accumulation of insoluble α-synuclein and increased proteasomal degradation of cysteine string protein α (CSPα). As a result, the availability of both α-synuclein and CSPα at nerve terminals strongly decreases, thus inhibiting soluble NSF attachment receptor (SNARE) complex assembly and synaptic vesicle recycling. Aberrant presynaptic SNARE phenotype is recapitulated in mice with genetic ablation of one allele of both CSPα and α-synuclein. The overexpression of CSPα in the brain of a mouse model of mucopolysaccharidosis type IIIA, a severe form of LSD, efficiently re-established SNARE complex assembly, thereby ameliorating presynaptic function, attenuating neurodegenerative signs, and prolonging survival. Our data show that neurodegenerative processes associated with lysosomal dysfunction may be presynaptically initiated by a concomitant reduction in α-synuclein and CSPα levels at nerve terminals. They also demonstrate that neurodegeneration in LSDs can be slowed down by re-establishing presynaptic functions, thus identifying synapse maintenance as a novel potentially druggable target for brain treatment in LSDs

Mechanisms by which autophagy regulates memory capacity in ageing

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