Publications by authors named "Antonio Musio"

59 Publications

Use of the SpineJack direct reduction for treating type A2, A3 and A4 fractures of the thoracolumbar spine: a retrospective case series.

J Neurointerv Surg 2021 Aug 25. Epub 2021 Aug 25.

Department of Spine Surgery, Ospedale Maggiore "C.A. Pizzardi", Bologna, Italy.

Background: Compression injuries of the thoracolumbar spine without neurological impairment are usually treated with minimally invasive procedures. Intravertebral expandable implants represent an alternative strategy in fractures with low fragments' displacement.

Methods: Patients with A2, A3 and A4 fractures of the T10-L2 spinal segment without neurological impairment, fracture gap >2 mm, vertebra plana, pedicle rupture, pedicle diameter <6 mm, spinal canal encroachment ≥50%, and vertebral body spread >30% were treated with the SpineJack device. Patients with pathological/osteoporotic fractures were excluded. Demographic and fracture-related data were assessed together with vertebral kyphosis correction, vertebral height restoration/loss of correction and final kyphosis. The modified Rankin Scale (mRS), Oswestry Disability Index (ODI), Visual Analogue Scale (VAS), Smiley-Webster Pain Scale (SWPS) and EuroQol-5D (EQ-5D) were evaluated at 1 (-post), 6 and 12 months (-fup) after surgery. Statistical analysis was performed and p values ≤0.05 were considered significant.

Results: Fifty-seven patients were included in the study. Patients aged >60 years reported worse kyphosis correction (<4°) with more postoperative complications, while vertebral plasticity in younger patients, fragmentation-related greater remodeling in A3/A4 fractures, and treatments within 7 days of trauma determined superior wedging corrections, with better EQ-5D-post and mRS-fup. Cement leakages did not affect functional outcome, while female gender and American Society of Anesthesiologists (ASA) score of 3-4 were associated with worse ODI-fup and VAS-fup. Although fracture characteristics and radiological outcome did not negatively influence the clinical outcome, A2 fracture was a risk factor for complications, thus indirectly compromising both the functional and radiological outcome.

Conclusion: With spread of <30%, the SpineJack is an alternative to minimally invasive fixations for treating A3/A4 thoracolumbar fractures, being able to preserve healthy motion segments in younger patients and provide an ultra-conservative procedure for elderly and fragile patients.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1136/neurintsurg-2021-017682DOI Listing
August 2021

Letter: Minimally Invasive Endoscopy for Acute Subdural Hematomas: A Report of 3 Cases.

Oper Neurosurg (Hagerstown) 2021 08;21(3):E296

Department of Neurosurgery San Carlo Regional Hospital Potenza, Italy.

View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1093/ons/opab208DOI Listing
August 2021

The Infratemporal Retro-Eustachian Transposition of the Temporoparietal Fascial Flap for Clival Reconstruction After Endoscopic Endonasal Approach: An Anatomic Conceptual Technique.

Oper Neurosurg (Hagerstown) 2021 06;21(1):E15-E21

Department of Neurosurgery, Stanford Medical Center, Stanford, California, USA.

Background: Reconstruction after endoscopic endonasal approaches is a key element. Lower clivus reconstruction is difficult and most of the times a pedicled flap is not available. As the complexity and the dimensions of the exposure increase, a reliable reconstruction technique becomes more and more important.

Objective: To describe the anatomic and technical nuances of the transposition of the temporoparietal fascial flap for lower clivus reconstruction.

Methods: A specific temporoparietal fascial flap (TPFF) design and tunneling technique has been studied using 4 head specimens, microscopic and endoscopic surgical techniques, and neuronavigation.

Results: The L-shaped flap offers several advantages. It can be tunneled directly toward the lower clivus passing through the infratemporal fossa.

Conclusion: The infratemporal retro-eustachian transposition of an L-shaped TPFF provides a vascularized tissue virtually without dimension limits. This is the only technique that allows the flap to be tunneled directly in the lower clivus with the most vascular portion being at the bottom of the defect. Clinical validation is still required since more issues may become relevant in a real-surgery setting. Though, due to its possible complications, this methodology needs further testing and should not be attempted in less experienced hands.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1093/ons/opab105DOI Listing
June 2021

Epidermoid cyst of the anterior clinoid process: report of a unique finding and literature review of the middle cranial fossa locations.

Clin Neurol Neurosurg 2021 01 27;200:106381. Epub 2020 Nov 27.

Maurizio Bufalini Hospital, Neurosurgery Department, Cesena, Italy.

Background: Epidermoids cysts are relatively rare, benign, congenital tumours, representing from 0.3% to 1.8% of all intracranial lesions. When extradural, they are most commonly reported in the temporal or parietal bones as intradiploic lesions; when intradural their most common location is the cerebellopontine angle and less frequently the middle cranial fossa. Herein we present a unique case of an extradural-intraosseous epidermoid cyst of the anterior clinoid process, integrating our single-case experience into a focused literature review of these lesions, when located in the middle cranial fossa.

Case Description: A 49 years old man came to our attention with history of head trauma. Urgent brain CT and elective brain MRI showed imaging suggestive for an anterior clinoid process epidermoid cyst. Through a pterional approach, the lesion was completely removed with microsurgical endoscope assisted technique. MRI at one year follow up showed no recurrence.

Methods: Current literature on epidermoid cysts located in middle cranial fossa was reviewed. A total of 22 papers, containing 70 epidermoid cyst were selected for the review. Symptoms at presentation; anatomic location; surgical approach; extent of resection and recurrence; outcome after surgery and at follow up were analysed for each case.

Conclusions: In the 70 published cases of middle fossa epidermoid cysts, the majority presented with trigeminal neuralgia. Most of the cases were operated through a pterional approach, while recent literature showed an increasing interest in endonasal endoscopic techniques. Subtotal resection is not a straight predictive value for recurrence; post-operative neurological deficits incidence is low and generally resolve at follow-up.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.clineuro.2020.106381DOI Listing
January 2021

Transpars approach for L5-S1 foraminal and extra-foraminal lumbar disc herniations: technical note.

J Neurosurg Sci 2020 Dec 9. Epub 2020 Dec 9.

Department of Morphology Surgery and Experimental Medicine, Ferrara University, Ferrara, Italy.

Background: The short pars and the narrowed surgical corridor for far lateral L5S1 herniation make the transpars approach challenging. The aim of this study is to determine the feasibility, efficacy and safety of the transpars microscopic approach for the treatment of L5-S1 foraminal and extraforaminal lumbar disc herniation.

Methods: From 2015 to 2019, patients with L5-S1 far lateral lumbar disc herniation were prospectively recruited. Drug intake, working days lost, NRS-leg, NRS-back, nerve-root palsy, Oswestry disability-index, Macnab criteria were recorded before surgery and at follow-up. Patients were seen at 1-6-12 months after surgery. Lumbar dynamic x-rays were performed at 6-12 months after surgery and again at 2-4 years after surgery. Key-steps of surgery are described.

Results: Fourteen patients were enrolled. NRS-leg and NRS-back scores significantly improved (from 7.93 to 1.43 and from 3.2 to 0.6, respectively-p<0.0001). Oswestry score significantly decreased (from 63.14 to 19.36 at 12 months; p<0.0001). L5 Root palsy improved in all cases (from 3.72/5 to 5/5; p<0.0001). At 12-months, excellent or good outcome (Macnab criteria) was achieved in 12 (85.7%) and 2 (14.3%) patients, respectively. All patients who were not retired returned to work within 30 days after surgery. No recurrence, instability or re-operations occurred.

Conclusions: The trans pars microscopic approach is feasible, safe and effective for L5-S1 foraminal and extraforaminal disc herniation. During surgery, the key-point is the oblique working angle, directed caudally, parallel to L5 pedicle. The iliac crest does not seem to constitute an obstacle.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.23736/S0390-5616.20.05165-6DOI Listing
December 2020

Cohesin mutations are synthetic lethal with stimulation of WNT signaling.

Elife 2020 12 7;9. Epub 2020 Dec 7.

Department of Pathology, Otago Medical School, University of Otago, Dunedin, New Zealand.

Mutations in genes encoding subunits of the cohesin complex are common in several cancers, but may also expose druggable vulnerabilities. We generated isogenic MCF10A cell lines with deletion mutations of genes encoding cohesin subunits SMC3, RAD21, and STAG2 and screened for synthetic lethality with 3009 FDA-approved compounds. The screen identified several compounds that interfere with transcription, DNA damage repair and the cell cycle. Unexpectedly, one of the top 'hits' was a GSK3 inhibitor, an agonist of Wnt signaling. We show that sensitivity to GSK3 inhibition is likely due to stabilization of β-catenin in cohesin-mutant cells, and that Wnt-responsive gene expression is highly sensitized in -mutant CMK leukemia cells. Moreover, Wnt activity is enhanced in zebrafish mutant for cohesin subunits and . Our results suggest that cohesin mutations could progress oncogenesis by enhancing Wnt signaling, and that targeting the Wnt pathway may represent a novel therapeutic strategy for cohesin-mutant cancers.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.7554/eLife.61405DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7746233PMC
December 2020

Simplified four-step retropharyngeal approach for the upper cervical spine: technical note.

Eur Spine J 2020 11 9;29(11):2752-2757. Epub 2020 Jul 9.

Department of Neurosurgery, Sant'Anna University Hospital, Viale Aldo Moro 8, 44124, Ferrara, Italy.

Purpose: In this paper, we propose a simplified four-step retropharyngeal approach, whose aim is getting straight to the upper cervical spine minimizing complications.

Methods: While the classical retropharyngeal approach includes about 11 steps, ours is a four-step approach: patient positioning, skin-platysma incision, hyoid bone superolateral dissection and retropharyngeal blunt exposure. We avoid several steps of the classical anterior retropharyngeal approach, particularly dissection of submandibular gland, facial veins, external carotid artery and thyroid artery, bellies of the digastric muscle, hypoglossal nerve, thyrohyoid membrane and the internal branch of superior laryngeal nerve.

Results: We have adopted this technique for five patients: two patients had a C2-C3 herniated disk with myelopathy, two patients had unstable Hangman fracture with no bone fusion after 2-month treatment with rigid collar, and one patient had a C2-C3 osteophyte with dysphagia. The intraoperative time needed for reaching the retropharyngeal space was 15 (first case), 9 (second case), 7 min (third case-illustrative case-and fourth case), 8 min (fifth case). No complications occurred.

Conclusion: Our simplification, avoiding several steps, is simple, effective, safe, and rapid and requires a simple learning curve.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s00586-020-06521-5DOI Listing
November 2020

Pathogenic variants in EP300 and ANKRD11 in patients with phenotypes overlapping Cornelia de Lange syndrome.

Am J Med Genet A 2020 07 31;182(7):1690-1696. Epub 2020 May 31.

Istituto di Ricerca Genetica e Biomedica, Consiglio Nazionale delle Ricerche, Pisa, Italy.

Cornelia de Lange syndrome (CdLS), Rubinstein-Taybi syndrome (RSTS), and KBG syndrome are three distinct developmental human disorders. Variants in seven genes belonging to the cohesin pathway, NIPBL, SMC1A, SMC3, HDAC8, RAD21, ANKRD11, and BRD4, were identified in about 80% of patients with CdLS, suggesting that additional causative genes remain to be discovered. Two genes, CREBBP and EP300, have been associated with RSTS, whereas KBG results from variants in ANKRD11. By exome sequencing, a genetic cause was elucidated in two patients with clinical diagnosis of CdLS but without variants in known CdLS genes. In particular, genetic variants in EP300 and ANKRD11 were identified in the two patients with CdLS. EP300 and ANKRD11 pathogenic variants caused the reduction of the respective proteins suggesting that their low levels contribute to CdLS-like phenotype. These findings highlight the clinical overlap between CdLS, RSTS, and KBG and support the notion that these rare disorders are linked to abnormal chromatin remodeling, which in turn affects the transcriptional machinery.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1002/ajmg.a.61611DOI Listing
July 2020

The multiple facets of the SMC1A gene.

Authors:
Antonio Musio

Gene 2020 Jun 25;743:144612. Epub 2020 Mar 25.

Institute for Genetic and Biomedical Research (IRGB), National Research Council (CNR), Pisa, Italy. Electronic address:

Structural Maintenance of Chromosomes (SMCs) are part of a large family of ring complexes that participates in a number of DNA transactions. Among SMCs, SMC1A gene is unique. It encodes a subunit of the cohesin-core complex that tethers sister chromatids together to ensure correct chromosome segregation in both mitosis and meiosis. As a member of the cohesin ring, SMC1A takes part in gene transcription regulation and genome organization; and it participates in the DNA Damage Repair (DDR) pathway, being phosphorylated by Ataxia Telangiectasia Mutated (ATM) and Ataxia Telangiectasia and Rad3 Related (ATR) threonine/serine kinases. It is also a component of the Recombination protein complex (RC-1) involved in DNA repair by recombination. SMC1A pathogenic variants have been described in Cornelia de Lange syndrome (CdLS), a human rare disease, and recently SMC1A variants have been associated with epilepsy or resembling Rett syndrome phenotype. Finally, SMC1A variants have been identified in several human cancers. In this review, our current knowledge of the SMC1A gene has been summarized.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.gene.2020.144612DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8011328PMC
June 2020

Chromosome Missegregation in Single Human Oocytes Is Related to the Age and Gene Expression Profile.

Int J Mol Sci 2020 Mar 12;21(6). Epub 2020 Mar 12.

Institute for Genetic and Biomedical Research (IRGB), National Research Council (CNR), 56124 Pisa, Italy.

The growing trend for women to postpone childbearing has resulted in a dramatic increase in the incidence of aneuploid pregnancies. Despite the importance to human reproductive health, the events precipitating female age-related meiotic errors are poorly understood. To gain new insight into the molecular basis of age-related chromosome missegregation in human oocytes, we combined the transcriptome profiles of twenty single oocytes (derived from females divided into two groups according to age <35 and ≥35 years) with their chromosome status obtained by array comparative genomic hybridization (aCGH). Furthermore, we compared the transcription profile of the single oocyte with the surrounding cumulus cells (CCs). RNA-seq data showed differences in gene expression between young and old oocytes. Dysregulated genes play a role in important biological processes such as gene transcription regulation, cytoskeleton organization, pathways related to RNA maturation and translation. The comparison of the transcription profile of the oocyte and the corresponding CCs highlighted the differential expression of genes belonging to the G protein-coupled receptor superfamily. Finally, we detected the loss of a X chromosome in two oocytes derived from women belonging to the ≥35 years age group. These aneuploidies may be caused by the detriment of REEP4, an endoplasmic reticulum protein, in women aged ≥35 years. Here we gained new insight into the complex regulatory circuit between the oocyte and the surrounding CCs and uncovered a new putative molecular basis of age-related chromosome missegregation in human oocytes.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3390/ijms21061934DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7139522PMC
March 2020

Filthy operative rooms and other mistakes during movies on neurosurgical procedures: Fascinating and powerful neurosurgical scenarios presented, in different ways, to non-neurosurgical society. How many mistakes and stereotypes can be made in movies for people not daily involved in medical life?

Clin Neurol Neurosurg 2020 04 1;191:105695. Epub 2020 Feb 1.

Department of Neurosurgery, S. Anna University Hospital, Ferrara, Italy.

Objectives: The brain and people "manipulating" it, provide a very mysterious and fascinating substrate for a movie. Faithful representation of reality often represent a key for the success of a film. Nonetheless, while watching movies with neurosurgical scenes, we often observed actions and elements containing incredible errors that aroused opposing emotions. The aim of this study was to perform an extensive review examining the representations of neurosurgery in movies, especially focused on the analysis of neurosurgical gross mistakes.

Patient And Methods: We looked for any movie that featured a neurosurgeon or a scene including a neurosurgical disease or procedure. We used one of the largest internet movie databases available online (IMDb.com) with searching for keywords such as "neurosurgeon", "neurosurgery", and "craniotomy". Title, year, genre and cost of production were collected. The first three features were detected on IMDb.com; the costs of production were found in websites the-numbers.com and boxofficemojo.com. Analysis and selection were performed by AM and PDB.

Result: 73 movies were found. After the application of inclusion/exclusion criteria, 58 have been eligible for inclusion in the study (Table 1) and 15 have been excluded from the final analysis". Out of 45 movies watched, we found 32 neurosurgical mistakes. Mistakes were classified into four big groups, namely: "surgical asepsis and principles of sterile technique" (n = 13, 40 %); "conceptual mistakes (n = 10, 31.5 %)"; "incorrect use of surgical tools (n = 7, 22 %)" ; "anatomical and radiological mistakes (n = 2, 6.5 %)". The costs of production started from 11.000 US dollars (Vsivaci, 2014) to 200 millions dollars (Spiderman 2, 2004), with a median value of 8.2 millions dollars each. All mistakes were not useful for the correct progress of the movie.

Conclusion: Our review shows that several mistakes, especially on asepsis during surgery are present in films dealing with neurosurgery. Several movies costed up to millions of dollars. Would a consultation of a Neurosurgeon before/during the shooting narrow the gap between the reality and fiction?
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.clineuro.2020.105695DOI Listing
April 2020

Evaluating Face2Gene as a Tool to Identify Cornelia de Lange Syndrome by Facial Phenotypes.

Int J Mol Sci 2020 Feb 4;21(3). Epub 2020 Feb 4.

Unit of Clinical Genetics and Functional Genomics, Department of Pharmacology-Physiology, School of Medicine, University of Zaragoza, CIBERER-GCV02 and ISS-Aragon, E-50009 Zaragoza, Spain.

Characteristic or classic phenotype of Cornelia de Lange syndrome (CdLS) is associated with a recognisable facial pattern. However, the heterogeneity in causal genes and the presence of overlapping syndromes have made it increasingly difficult to diagnose only by clinical features. DeepGestalt technology, and its app Face2Gene, is having a growing impact on the diagnosis and management of genetic diseases by analysing the features of affected individuals. Here, we performed a phenotypic study on a cohort of 49 individuals harbouring causative variants in known CdLS genes in order to evaluate Face2Gene utility and sensitivity in the clinical diagnosis of CdLS. Based on the profile images of patients, a diagnosis of CdLS was within the top five predicted syndromes for 97.9% of our cases and even listed as first prediction for 83.7%. The age of patients did not seem to affect the prediction accuracy, whereas our results indicate a correlation between the clinical score and affected genes. Furthermore, each gene presents a different pattern recognition that may be used to develop new neural networks with the goal of separating different genetic subtypes in CdLS. Overall, we conclude that computer-assisted image analysis based on deep learning could support the clinical diagnosis of CdLS.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3390/ijms21031042DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7038094PMC
February 2020

Cornelia de Lange syndrome: from molecular diagnosis to therapeutic approach.

J Med Genet 2020 05 8;57(5):289-295. Epub 2019 Nov 8.

Istituto di Ricerca Genetica e Biomedica, Consiglio Nazionale delle Ricerche, Pisa, Italy

Cornelia de Lange syndrome (CdLS) is a severe genetic disorder characterised by multisystemic malformations. CdLS is due to pathogenetic variants in , , , and genes which belong to the cohesin pathway. Cohesin plays a pivotal role in chromatid cohesion, gene expression, and DNA repair. In this review, we will discuss how perturbations in those biological processes contribute to CdLS phenotype and will emphasise the state-of-art of CdLS therapeutic approaches.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1136/jmedgenet-2019-106277DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7231464PMC
May 2020

p53 mitotic centrosome localization preserves centrosome integrity and works as sensor for the mitotic surveillance pathway.

Cell Death Dis 2019 11 7;10(11):850. Epub 2019 Nov 7.

Unit of Cellular Networks and Molecular Therapeutic Targets, IRCCS-Regina Elena National Cancer Institute, Rome, Italy.

Centrosomal p53 has been described for three decades but its role is still unclear. We previously reported that, in proliferating human cells, p53 transiently moves to centrosomes at each mitosis. Such p53 mitotic centrosome localization (p53-MCL) occurs independently from DNA damage but requires ATM-mediated p53Ser15 phosphorylation (p53Ser15) on discrete cytoplasmic p53 foci that, through MT dynamics, move to centrosomes during the mitotic spindle formation. Here, we show that inhibition of p53-MCL, obtained by p53 depletion or selective impairment of p53 centrosomal localization, induces centrosome fragmentation in human nontransformed cells. In contrast, tumor cells or mouse cells tolerate p53 depletion, as expected, and p53-MCL inhibition. Such tumor- and species-specific behavior of centrosomal p53 resembles that of the recently identified sensor of centrosome-loss, whose activation triggers the mitotic surveillance pathway in human nontransformed cells but not in tumor cells or mouse cells. The mitotic surveillance pathway prevents the growth of human cells with increased chance of making mitotic errors and accumulating numeral chromosome defects. Thus, we evaluated whether p53-MCL could work as a centrosome-loss sensor and contribute to the activation of the mitotic surveillance pathway. We provide evidence that centrosome-loss triggered by PLK4 inhibition makes p53 orphan of its mitotic dock and promotes accumulation of discrete p53Ser15 foci. These p53 foci are required for the recruitment of 53BP1, a key effector of the mitotic surveillance pathway. Consistently, cells from patients with constitutive impairment of p53-MCL, such as ATM- and PCNT-mutant carriers, accumulate numeral chromosome defects. These findings indicate that, in nontransformed human cells, centrosomal p53 contributes to safeguard genome integrity by working as sensor for the mitotic surveillance pathway.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/s41419-019-2076-1DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6838180PMC
November 2019

Reciprocal Regulation of TRPS1 and miR-221 in Intervertebral Disc Cells.

Cells 2019 09 28;8(10). Epub 2019 Sep 28.

Department of Biomedical and Specialty Surgical Sciences, University of Ferrara, 44121 Ferrara, Italy.

Intervertebral disc (IVD), a moderately moving joint located between the vertebrae, has a limited capacity for self-repair, and treating injured intervertebral discs remains a major challenge. The development of innovative therapies to reverse IVD degeneration relies primarily on the discovery of key molecules that, occupying critical points of regulatory mechanisms, can be proposed as potential intradiscal injectable biological agents. This study aimed to elucidate the underlying mechanism of the reciprocal regulation of two genes differently involved in IVD homeostasis, the miR-221 microRNA and the TRPS1 transcription factor. Human lumbar IVD tissue samples and IVD primary cells were used to specifically evaluate gene expression and perform functional analysis including the luciferase gene reporter assay, chromatin immunoprecipitation, cell transfection with hTRPS1 overexpression vector and antagomiR-221. A high-level expression of TRPS1 was significantly associated with a lower pathological stage, and TRPS1 overexpression strongly decreased miR-221 expression, while increasing the chondrogenic phenotype and markers of antioxidant defense and stemness. Additionally, TRPS1 was able to repress miR-221 expression by associating with its promoter and miR-221 negatively control TRPS1 expression by targeting the -3'UTR gene. As a whole, these results suggest that, in IVD cells, a double-negative feedback loop between a potent chondrogenic differentiation suppressor (miR-221) and a regulator of axial skeleton development (TRPS1) exists. Our hypothesis is that the hostile degenerated IVD microenvironment may be counteracted by regenerative/reparative strategies aimed at maintaining or stimulating high levels of TRPS1 expression through inhibition of one of its negative regulators such as miR-221.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3390/cells8101170DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6829335PMC
September 2019

Functional Outcome of Elderly Patients Treated for Odontoid Fracture: A Multicenter Study.

Spine (Phila Pa 1976) 2019 Jul;44(13):951-958

Neurosurgery Division, "M. Bufalini" Hospital, Cesena, Italy.

Study Design: Retrospective multicenter study.

Objective: Analysis of impact of conservative and surgical treatments on functional outcome of geriatric odontoid fractures.

Summary Of Background Data: Treatment of odontoid fractures in aged population is still debatable.

Methods: One hundred fourty-seven consecutive odontoid fractures in elderly patients were classified according to Anderson-D'Alonzo and Roy-Camille classifications. Philadelphia type collar was always positioned and kept as a treatment whenever acceptable. Halo-vest, anterior screw fixation, C1-C2 posterior arthrodesis, and occipito-cervical fixation were the other treatments adopted. Conservative or surgical treatment strategy was more significantly influenced by antero-posterior displacement (< or >5 mm) and by surgeon decision. On admission ASA, modified Rankin scale (mRS-pre) and Charlson Comorbidity Index (CCI) were assessed. Modified Rankin scale (mRS-post), Neck Disability Index (NDI), and Smiley Webster Pain Scale (SWPS) were administered 12 to 15 months after treatment to estimate functional outcome in terms of general disability, neck-related disability, and ability to return to work/former activity. Risk of treatment crossover was calculated considering factors affecting outcome. Fracture healing process in terms of fusion-stability, no fusion-stability, no fusion-no stability was evaluated at 12 months through a cervical computed tomography (CT) scan. Dynamic cervical spine x-rays were obtained whether necessary. No fusion-stability was considered an adequate treatment goal in our geriatric population. Chi square/Fisher exact test and logistic regression were performed for statistical anal.

Results: Overall 67 patients were treated conservatively whereas 80 underwent surgery. Collar was adopted in 45 patients, while anterior odontoid fixation and C1-C2 posterior arthrodesis were preferred for 30 patients each. 79.8% of patients showed good outcomes according to NDI. No significant differences were observed between patients of 65 to 79 years and more than or equal to 80 years (P = 0.81). CCI greatly correlated with mRS-post, with higher indexes in 68.8% of cases characterized by good outcomes (P = 0.05). mRS-pre correlated with NDI (P < 0.000001) and mRS-post (P = 0.04). CCI, mRS-pre, and surgery were associated with worse NDI, while both C1-C2 posterior arthrodesis and occipito-cervical stabilization were associated with worse mRS-post, respectively in 40% and 30% of cases. Younger patients had a higher risk of treatment crossover.

Conclusion: mRS-pre and CCI provided two independent predictive values respectively for functional outcome and post-treatment disability. Compared with conservative immobilizations, surgery revealed no advantages in the elderly in terms of functional outcome.

Level Of Evidence: 3.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1097/BRS.0000000000002982DOI Listing
July 2019

Cornelia de Lange syndrome, related disorders, and the Cohesin complex: Abstracts from the 8th biennial scientific and educational symposium 2018.

Am J Med Genet A 2019 06 15;179(6):1080-1090. Epub 2019 Mar 15.

Research Department, Cornelia de Lange Syndrome Foundation, Avon, Connecticut.

Cornelia de Lange Syndrome (CdLS), due to mutations in genes of the cohesin protein complex, is described as a disorder of transcriptional regulation. Phenotypes in this expanding field include short stature, microcephaly, intellectual disability, variable facial features and organ involvement, resulting in overlapping presentations, including established syndromes and newly described conditions. Individuals with all forms of CdLS have multifaceted complications, including neurodevelopmental, feeding, craniofacial, and communication. Coping mechanisms and management of challenging behaviors in CdLS, disruption of normal behaviors, and how behavior molds the life of the individual within the family is now better understood. Some psychotropic medications are known to be effective for behavior. Other medications, for example, Indomethacin, are being investigated for effects on gene expression, fetal brain tissue, brain morphology and function in Drosophila, mice, and human fibroblasts containing CdLS-related mutations. Developmental studies have clarified the origin of cardiac defects and role of placenta in CdLS. Chromosome architecture and cohesin complex structure are elucidated, leading to a better understanding of regulatory aspects and controls. As examples, when mutations are present, the formation of loop domains by cohesin, facilitating enhancer-promotor interactions, can be eliminated, and embryologically, the nuclear structure of zygotes is disrupted. Several important genes are now known to interact with cohesin, including Brca2. The following abstracts are from the 8th Cornelia de Lange Syndrome Scientific and Educational Symposium, held in June 2018, Minneapolis, MN, before the CdLS Foundation National Meeting, AMA CME credits provided by GBMC, Baltimore, MD. All studies have been approved by an ethics committee.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1002/ajmg.a.61108DOI Listing
June 2019

Overexpression of the cohesin-core subunit SMC1A contributes to colorectal cancer development.

J Exp Clin Cancer Res 2019 Mar 1;38(1):108. Epub 2019 Mar 1.

Institute for Genetic and Biomedical Research (IRGB), National Research Council (CNR), Via Moruzzi, 1, 56124, Pisa, Italy.

Background: Cancer cells are characterized by chromosomal instability (CIN) and it is thought that errors in pathways involved in faithful chromosome segregation play a pivotal role in the genesis of CIN. Cohesin forms a large protein ring that binds DNA strands by encircling them. In addition to this central role in chromosome segregation, cohesin is also needed for DNA repair, gene transcription regulation and chromatin architecture. Though mutations in both cohesin and cohesin-regulator genes have been identified in many human cancers, the contribution of cohesin to cancer development is still under debate.

Methods: Normal mucosa, early adenoma, and carcinoma samples deriving from 16 subjects affected by colorectal cancer (CRC) were analyzed by OncoScan for scoring both chromosome gains and losses (CNVs) and loss of heterozygosity (LOH). Then the expression of SMC1A was analyzed by immunochemistry in 66 subjects affected by CRC. The effects of SMC1A overexpression and mutated SMC1A were analyzed in vivo using immunocompromised mouse models. Finally, we measured global gene expression profiles in induced-tumors by RNA-seq.

Results: Here we showed that SMC1A cohesin core gene was present as extra-copies, mutated, and overexpressed in human colorectal carcinomas. We then demonstrated that cohesin overexpression led to the development of aggressive cancers in immunocompromised mice through gene expression dysregulation.

Conclusion: Collectively, these results support a role of defective cohesin in the development of human colorectal cancer.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1186/s13046-019-1116-0DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6397456PMC
March 2019

Type II odontoid fracture in elderly patients treated conservatively: is fracture healing the goal?

Eur Spine J 2019 05 23;28(5):1064-1071. Epub 2019 Jan 23.

Neurosurgery Division, University Hospital S.Anna, Viale Aldo Moro 8, 44121, Cona di Ferrara, Italy.

Purpose: Analysis of functional outcome of elderly patients with type II odontoid fractures treated conservatively in relation to their radiological outcome.

Methods: A total of 50 geriatric patients with type II odontoid fractures were treated with Aspen/Vista collars. On admission, each patient was assessed assigning ASA score, modified Rankin Scale (mRS-pre) and Charlson Comorbidity Index (CCI). From 12-15 months after treatment, functional evaluations were performed employing a second modified Rankin Scale (mRS-post) together with Neck Disability Index (NDI) and Smiley-Webster pain scale (SWPS). Radiological outcome was evaluated through dynamic cervical spine X-rays at 3 months and cervical spine CT scans 6 months after treatment. Three different conditions were identified: stable union, stable non-union and unstable non-union. Surgery was preferred whenever a fracture gap > 2 mm, an antero-posterior displacement > 5 mm, an odontoid angulation > 11° or neurological deficits occurred.

Results: Among the 50 patients, 24 reached a stable union, while 26 a stable non-union. Comparing the two groups, no differences in ASA (p = 0.60), CCI (p = 0.85) and mRS-pre (p = 0.14) were noted. Similarly, no differences in mRS-post (p = 0.96), SWPS (p = 0.85) and NDI (p = 0.51) were observed between patients who reached an osseous fusion and those with a stable fibrous non-union. No effects of age, sex, ASA, mRS-pre, fracture dislocation and radiological outcome were discovered on functional outcome. At logistic regression analysis, female sex and high values of CCI emerged associated with worse NDI.

Conclusions: In geriatric type II odontoid fractures, pre-injury clinical status and comorbidities overcome imaging in determining post-treatment level of function. Hard collar immobilization led to a favourable functional outcome with mRS-post, NDI and SWPS values diffusely encouraging whatever a bony union or a fibrous non-union was obtained. These slides can be retrieved under Electronic Supplementary Material.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s00586-019-05898-2DOI Listing
May 2019

Functional Outcome After Odontoid Fractures in the Elderly.

Acta Neurochir Suppl 2019;125:329-333

Neurosurgery, Sant'Anna University Hospital, Ferrara, Italy.

While several papers on mortality and the fusion rate in elderly patients treated surgically or non-surgically for odontoid fractures exist, little information is available on quality of life after treatment. The aim of treatment in these patients should not be fracture healing alone but also quality of life improvement.A literature search using PubMed identified seven papers including information on functional evaluation of 402 patients.Patients treated with anterior screw fixation had a good functional outcome in 92.6% of cases. This percentage seemed to decrease in octogenarians. Less information was available for patients treated with posterior approaches; it would seem that up to a half of such patients experienced pain and limitations in activities of daily living after surgery. Patients treated with a halo device had a functional outcome that was worse (or at least no better) than that of patients treated with surgery, with absence of limitations in activities of daily living in 77.3% of patients. Patients treated with a collar had a good functional outcome in the majority of cases, with absence of limitations in activities of daily living in 89% of patients.More studies are needed for evaluation of functional outcome, especially in patients treated with a collar, a halo device or a posterior approach.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/978-3-319-62515-7_48DOI Listing
August 2019

Antioxidant treatment ameliorates phenotypic features of SMC1A-mutated Cornelia de Lange syndrome in vitro and in vivo.

Hum Mol Genet 2018 09;27(17):3002-3011

Institute for Genetic and Biomedical Research, National Research Council, Pisa, Italy.

Cornelia de Lange syndrome (CdLS) is a rare disease characterized by cognitive impairment, multisystemic alterations and premature aging. Furthermore, CdLS cells display gene expression dysregulation and genomic instability. Here, we demonstrated that treatment with antioxidant drugs, such as ascorbic acid and riboceine, reduced the level of genomic instability and extended the in vitro lifespan of CdLS cell lines. We also found that antioxidant treatment partially rescued the phenotype of a zebrafish model of CdLS. Gene expression profiling showed that antioxidant drugs caused dysregulation of gene transcription; notably, a number of genes coding for the zinc finger (ZNF)-containing Krueppel-associated box (KRAB) protein domain (KRAB-ZNF) were found to be downregulated. Taken together, these data suggest that antioxidant drugs have the potential to ameliorate the developmental phenotype of CdLS.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1093/hmg/ddy203DOI Listing
September 2018

Separase prevents genomic instability by controlling replication fork speed.

Nucleic Acids Res 2018 01;46(1):267-278

Institute for Biomedical and Genetic Research, National Research Council, Pisa, Italy.

Proper chromosome segregation is crucial for preserving genomic integrity, and errors in this process cause chromosome mis-segregation, which may contribute to cancer development. Sister chromatid separation is triggered by Separase, an evolutionary conserved protease that cleaves the cohesin complex, allowing the dissolution of sister chromatid cohesion. Here we provide evidence that Separase participates in genomic stability maintenance by controlling replication fork speed. We found that Separase interacted with the replication licensing factors MCM2-7, and genome-wide data showed that Separase co-localized with MCM complex and cohesin. Unexpectedly, the depletion of Separase increased the fork velocity about 1.5-fold and caused a strong acetylation of cohesin's SMC3 subunit and altered checkpoint response. Notably, Separase silencing triggered genomic instability in both HeLa and human primary fibroblast cells. Our results show a novel mechanism for fork progression mediated by Separase and thus the basis for genomic instability associated with tumorigenesis.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1093/nar/gkx1172DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5758895PMC
January 2018

Cornelia de Lange syndrome and molecular implications of the cohesin complex: Abstracts from the 7th biennial scientific and educational symposium 2016.

Am J Med Genet A 2017 May 12;173(5):1172-1185. Epub 2017 Feb 12.

Cornelia de Lange Syndrome Foundation, Avon, Connecticut.

Cornelia de Lange Syndrome (CdLS) is due to mutations in the genes for the structural and regulatory proteins that make up the cohesin complex, and is considered a cohesinopathy disorder or, more recently, a transcriptomopathy. New phenotypes have been recognized in this expanding field. There are multiple clinical issues facing individuals with all forms of CdLS, particularly in the neurodevelopmental system, but also gastrointestinal, cardiac, and musculoskeletal. Aspects of developmental and cell biology have found common endpoints in the biology of the cohesin complex, with improved understanding of the mechanisms, easier diagnostic tests, and the possibility of potential therapeutics, all major clinical implications for the individual with CdLS. The following abstracts are the presentations from the 7th Cornelia de Lange Syndrome Scientific and Educational Symposium, June 22-23, 2016, in Orlando, FL, in conjunction with the Cornelia de Lange Syndrome Foundation National Meeting. In addition to the scientific and clinical discussions, there were talks related to practical aspects of behavior including autism, transitions, communication, access to medical care, and databases. At the end of the symposium, a panel was held, which included several parents, affected individuals and genetic counselors, and discussed the greatest challenges in life and how this information can assist in guiding future research. The Research Committee of the CdLS Foundation organizes this meeting, reviews, and accepts abstracts, and subsequently disseminates the information to the families through members of the Clinical Advisory Board and publications. AMA CME credits were provided by Greater Baltimore Medical Center, Baltimore, MD.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1002/ajmg.a.38161DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5758041PMC
May 2017

Genome stability: What we have learned from cohesinopathies.

Am J Med Genet C Semin Med Genet 2016 06 19;172(2):171-8. Epub 2016 Apr 19.

Cohesin is a multiprotein complex involved in many DNA-related processes such as proper chromosome segregation, replication, transcription, and repair. Mutations in cohesin gene pathways are responsible for human diseases, collectively referred to as cohesinopathies. In addition, both cohesin gene expression dysregulation and mutations have been identified in cancer. Cohesinopathy cells are characterized by genome instability (GIN) visualized by a constellation of markers such as chromosome aneuploidies, chromosome aberrations, precocious sister chromatid separation, premature centromere separation, micronuclei formation, and sensitivity to genotoxic drugs. The emerging picture suggests that GIN observed in cohesinopathies may result from the synergistic effects of the multiple cohesin dysfunctions. © 2016 Wiley Periodicals, Inc.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1002/ajmg.c.31492DOI Listing
June 2016

A role for Separase in telomere protection.

Nat Commun 2016 Jan 18;7:10405. Epub 2016 Jan 18.

Department of Biology and Biotechnology "Charles Darwin" Section of Genetics, SAPIENZA University of Rome, P.le Aldo Moro 5, 00185 Rome, Italy.

Drosophila telomeres are elongated by transposition of specialized retroelements rather than telomerase activity and are assembled independently of the sequence. Fly telomeres are protected by the terminin complex that localizes and functions exclusively at telomeres and by non-terminin proteins that do not serve telomere-specific functions. We show that mutations in the Drosophila Separase encoding gene Sse lead not only to endoreduplication but also telomeric fusions (TFs), suggesting a role for Sse in telomere capping. We demonstrate that Separase binds terminin proteins and HP1, and that it is enriched at telomeres. Furthermore, we show that loss of Sse strongly reduces HP1 levels, and that HP1 overexpression in Sse mutants suppresses TFs, suggesting that TFs are caused by a HP1 diminution. Finally, we find that siRNA-induced depletion of ESPL1, the Sse human orthologue, causes telomere dysfunction and HP1 level reduction in primary fibroblasts, highlighting a conserved role of Separase in telomere protection.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/ncomms10405DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4735636PMC
January 2016

SMC1B is present in mammalian somatic cells and interacts with mitotic cohesin proteins.

Sci Rep 2015 Dec 17;5:18472. Epub 2015 Dec 17.

Istituto di Ricerca Genetica e Biomedica, Consiglio Nazionale delle Ricerche, Pisa, Italy.

Cohesin is an evolutionarily conserved protein complex that plays a role in many biological processes: it ensures faithful chromosome segregation, regulates gene expression and preserves genome stability. In mammalian cells, the mitotic cohesin complex consists of two structural maintenance of chromosome proteins, SMC1A and SMC3, the kleisin protein RAD21 and a fourth subunit either STAG1 or STAG2. Meiotic paralogs in mammals were reported for SMC1A, RAD21 and STAG1/STAG2 and are called SMC1B, REC8 and STAG3 respectively. It is believed that SMC1B is only a meiotic-specific cohesin member, required for sister chromatid pairing and for preventing telomere shortening. Here we show that SMC1B is also expressed in somatic mammalian cells and is a member of a mitotic cohesin complex. In addition, SMC1B safeguards genome stability following irradiation whereas its ablation has no effect on chromosome segregation. Finally, unexpectedly SMC1B depletion impairs gene transcription, particularly at genes mapping to clusters such as HOX and PCDHB. Genome-wide analyses show that cluster genes changing in expression are enriched for cohesin-SMC1B binding.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/srep18472DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4682075PMC
December 2015

Mutant cohesin affects RNA polymerase II regulation in Cornelia de Lange syndrome.

Sci Rep 2015 Nov 19;5:16803. Epub 2015 Nov 19.

Istituto di Ricerca Genetica e Biomedica, Consiglio Nazionale delle Ricerche, Pisa, Italy.

In addition to its role in sister chromatid cohesion, genome stability and integrity, the cohesin complex is involved in gene transcription. Mutations in core cohesin subunits SMC1A, SMC3 and RAD21, or their regulators NIPBL and HDAC8, cause Cornelia de Lange syndrome (CdLS). Recent evidence reveals that gene expression dysregulation could be the underlying mechanism for CdLS. These findings raise intriguing questions regarding the potential role of cohesin-mediated transcriptional control and pathogenesis. Here, we identified numerous dysregulated genes occupied by cohesin by combining the transcriptome of CdLS cell lines carrying mutations in SMC1A gene and ChIP-Seq data. Genome-wide analyses show that genes changing in expression are enriched for cohesin-binding. In addition, our results indicate that mutant cohesin impairs both RNA polymerase II (Pol II) transcription initiation at promoters and elongation in the gene body. These findings highlight the pivotal role of cohesin in transcriptional regulation and provide an explanation for the typical gene dysregulation observed in CdLS patients.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/srep16803DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4652179PMC
November 2015

AKTIP/Ft1, a New Shelterin-Interacting Factor Required for Telomere Maintenance.

PLoS Genet 2015 Jun 25;11(6):e1005167. Epub 2015 Jun 25.

Dipartimento di Biologia e Biotecnologie, Sapienza-Università di Roma, Roma, Italy; Istituto Pasteur Fondazione Cenci Bolognetti, Sapienza-Università di Roma, Roma, Italy; Istituto di Biologia e Patologia Molecolari del CNR, Sapienza-Università di Roma, Roma, Italy.

Telomeres are nucleoprotein complexes that protect the ends of linear chromosomes from incomplete replication, degradation and detection as DNA breaks. Mammalian telomeres are protected by shelterin, a multiprotein complex that binds the TTAGGG telomeric repeats and recruits a series of additional factors that are essential for telomere function. Although many shelterin-associated proteins have been so far identified, the inventory of shelterin-interacting factors required for telomere maintenance is still largely incomplete. Here, we characterize AKTIP/Ft1 (human AKTIP and mouse Ft1 are orthologous), a novel mammalian shelterin-bound factor identified on the basis of its homology with the Drosophila telomere protein Pendolino. AKTIP/Ft1 shares homology with the E2 variant ubiquitin-conjugating (UEV) enzymes and has been previously implicated in the control of apoptosis and in vesicle trafficking. RNAi-mediated depletion of AKTIP results in formation of telomere dysfunction foci (TIFs). Consistent with these results, AKTIP interacts with telomeric DNA and binds the shelterin components TRF1 and TRF2 both in vivo and in vitro. Analysis of AKTIP- depleted human primary fibroblasts showed that they are defective in PCNA recruiting and arrest in the S phase due to the activation of the intra S checkpoint. Accordingly, AKTIP physically interacts with PCNA and the RPA70 DNA replication factor. Ft1-depleted p53-/- MEFs did not arrest in the S phase but displayed significant increases in multiple telomeric signals (MTS) and sister telomere associations (STAs), two hallmarks of defective telomere replication. In addition, we found an epistatic relation for MST formation between Ft1 and TRF1, which has been previously shown to be required for replication fork progression through telomeric DNA. Ch-IP experiments further suggested that in AKTIP-depleted cells undergoing the S phase, TRF1 is less tightly bound to telomeric DNA than in controls. Thus, our results collectively suggest that AKTIP/Ft1 works in concert with TRF1 to facilitate telomeric DNA replication.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1371/journal.pgen.1005167DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4481533PMC
June 2015

Clinical, developmental and molecular update on Cornelia de Lange syndrome and the cohesin complex: abstracts from the 2014 Scientific and Educational Symposium.

Am J Med Genet A 2015 Jun 21;167(6):1179-92. Epub 2015 Apr 21.

Cornelia de Lange Syndrome Foundation, Avon, Connecticut.

Cornelia de Lange Syndrome (CdLS) is the most common example of disorders of the cohesin complex, or cohesinopathies. There are a myriad of clinical issues facing individuals with CdLS, particularly in the neurodevelopmental system, which also have implications for the parents and caretakers, involved professionals, therapists, and schools. Basic research in developmental and cell biology on cohesin is showing significant progress, with improved understanding of the mechanisms and the possibility of potential therapeutics. The following abstracts are presentations from the 6th Cornelia de Lange Syndrome Scientific and Educational Symposium, which took place on June 25-26, 2014, in conjunction with the Cornelia de Lange Syndrome Foundation National Meeting in Costa Mesa, CA. The Research Committee of the CdLS Foundation organizes the meeting, reviews and accepts abstracts, and subsequently disseminates the information to the families through members of the Clinical Advisory Board. In addition to the scientific and clinical discussions, there were educationally focused talks related to practical aspects of behavior and development. AMA CME credits were provided by Greater Baltimore Medical Center, Baltimore, MD.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1002/ajmg.a.37056DOI Listing
June 2015

Proliferation of Multiple Cell Types in the Skeletal Muscle Tissue Elicited by Acute p21 Suppression.

Mol Ther 2015 May 11;23(5):885-895. Epub 2015 Feb 11.

Department of Cell Biology and Neurosciences, National Institute of Health, Rome, Italy. Electronic address:

Although in the last decades the molecular underpinnings of the cell cycle have been unraveled, the acquired knowledge has been rarely translated into practical applications. Here, we investigate the feasibility and safety of triggering proliferation in vivo by temporary suppression of the cyclin-dependent kinase inhibitor, p21. Adeno-associated virus (AAV)-mediated, acute knockdown of p21 in intact skeletal muscles elicited proliferation of multiple, otherwise quiescent cell types, notably including satellite cells. Compared with controls, p21-suppressed muscles exhibited a striking two- to threefold expansion in cellularity and increased fiber numbers by 10 days post-transduction, with no detectable inflammation. These changes partially persisted for at least 60 days, indicating that the muscles had undergone lasting modifications. Furthermore, morphological hyperplasia was accompanied by 20% increases in maximum strength and resistance to fatigue. To assess the safety of transiently suppressing p21, cells subjected to p21 knockdown in vitro were analyzed for γ-H2AX accumulation, DNA fragmentation, cytogenetic abnormalities, ploidy, and mutations. Moreover, the differentiation competence of p21-suppressed myoblasts was investigated. These assays confirmed that transient suppression of p21 causes no genetic damage and does not impair differentiation. Our results establish the basis for further exploring the manipulation of the cell cycle as a strategy in regenerative medicine.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/mt.2015.27DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4424006PMC
May 2015
-->