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Lattanzi G.,Institute of Molecular Genetics | Marmiroli S.,University of Modena and Reggio Emilia | Facchini A.,Laboratory of Immunorheumatology and Tissue Regeneration | Maraldi N.M.,Laboratory of Musculoskeletal Cell Biology | Maraldi N.M.,University of Bologna
European Journal of Histochemistry | Year: 2012

Mutations in genes encoding nuclear envelope proteins, particularly LMNA encoding the A-type lamins, cause a broad range of diverse diseases, referred to as laminopathies. The astonishing variety of diseased phenotypes suggests that different mechanisms could be involved in the pathogenesis of laminopathies. In this review we will focus mainly on two of these pathogenic mechanisms: the nuclear damages affecting the chromatin organization, and the oxidative stress causing un-repairable DNA damages. Alteration in the nuclear profile and in chromatin organization, which are particularly impressive in systemic laminopathies whose cells undergo premature senescence, are mainly due to accumulation of unprocessed prelamin A. The toxic effect of these molecular species, which interfere with chromatin-associated proteins, transcription factors, and signaling pathways, could be reduced by drugs which reduce their farnesylation and/or stability. In particular, inhibitors of farnesyl transferase (FTIs), have been proved to be active in rescuing the altered cellular phenotype, and statins, also in association with other drugs, have been included into pilot clinical trials. The identification of a mechanism that accounts for accumulation of unrepairable DNA damage due to reactive oxygen species (ROS) generation in laminopathic cells, similar to that found in other muscular dystrophies (MDs) caused by altered expression of extracellular matrix (ECM) components, suggests that anti-oxidant therapeutic strategies might prove beneficial to laminopathic patients. © G. Lattanzi et al., 2012.


Olivieri F.,Marche Polytechnic University | Olivieri F.,National Institute INRCA IRCCS | Bonafe M.,University of Bologna | Bonafe M.,CNR Institute of Molecular Genetics | And 24 more authors.
Aging | Year: 2014

Circulating miR-126-3p levels were determined in 136 healthy subjects (CTRs) aged 20-90 years and 193 patients with type-2 diabetes mellitus (T2DMs) aged 40-80 years, to explore the combined effect of age and glycemic state on miR-126-3p expression. Moreover, intra/extracellular miR-126-3p levels were measured in human endothelial cells (HUVECs) undergoing senescence under normo/hyper-glycemic conditions. Plasma miR-126-3p was significantly higher in the oldest compared with the youngest CTRs (<45 vs. >75 years; relative expression: 0.27±0.29 vs. 0.48±0.39, p=0.047). Age-based comparison between CTRs and T2DM demonstrated significantly different miR-126-3p levels only in the oldest (0.48±0.39 vs. 0.22±0.23, p<0.005). After multiple adjustments, miR-126-3p levels were seen to be lower in patients with poor glycemic control, compared with age-matched CTRs. The age-related increase in plasma miR-126-3p found in CTRs was paralleled by a 5/6-fold increase in intra/extracellular miR-126-3p in in vitro-cultured HUVECs undergoing senescence. Notably, significant down- regulation of SPRED-1 protein, a validated miR-126-3p target, was found in senescent HUVECs. Moreover, miR-126-3p expression was down-regulated in intermediate-age HUVECs grown in high-glucose medium until senescence. Aging/senescence-associated miR-126-3p up-regulation is likely a senescence-associated compensatory mechanism that is blunted when endothelial cells are exposed to high glucose levels, a phenomenon that probably occurs in vivo in T2DM patients. © Olivieri et al.


Zimon M.,University of Antwerp | Baets J.,University of Antwerp | Auer-Grumbach M.,Medical University of Graz | Berciano J.,University of Cantabria | And 21 more authors.
Brain | Year: 2010

Hereditary neuropathies form a heterogeneous group of disorders for which over 40 causal genes have been identified to date. Recently, dominant mutations in the transient receptor potential vanilloid 4 gene were found to be associated with three distinct neuromuscular phenotypes: hereditary motor and sensory neuropathy 2C, scapuloperoneal spinal muscular atrophy and congenital distal spinal muscular atrophy. Transient receptor potential vanilloid 4 encodes a cation channel previously implicated in several types of dominantly inherited bone dysplasia syndromes. We performed DNA sequencing of the coding regions of transient receptor potential vanilloid 4 in a cohort of 145 patients with various types of hereditary neuropathy and identified five different heterozygous missense mutations in eight unrelated families. One mutation arose de novo in an isolated patient, and the remainder segregated in families. Two of the mutations were recurrent in unrelated families. Four mutations in transient receptor potential vanilloid 4 targeted conserved arginine residues in the ankyrin repeat domain, which is believed to be important in protein-protein interactions. Striking phenotypic variability between and within families was observed. The majority of patients displayed a predominantly, or pure, motor neuropathy with axonal characteristics observed on electrophysiological testing. The age of onset varied widely, ranging from congenital to late adulthood onset. Various combinations of additional features were present in most patients including vocal fold paralysis, scapular weakness, contractures and hearing loss. We identified six asymptomatic mutation carriers, indicating reduced penetrance of the transient receptor potential vanilloid 4 defects. This finding is relatively unusual in the context of hereditary neuropathies and has important implications for diagnostic testing and genetic counselling. © The Author (2010).


Papi A.,University of Bologna | De Carolis S.,University of Bologna | Bertoni S.,University of Bologna | Storci G.,University of Bologna | And 8 more authors.
Journal of Cellular Physiology | Year: 2014

Cancer stem cells (CSCs) are affected by the local micro-environment, the niche, in which inflammatory stimuli and hypoxia act as steering factors. Here, two nuclear receptors (NRs) agonists, i.e. pioglitazone (PGZ), a ligand of peroxisome proliferator activated receptor-γ, and 6-OH-11-O-hydroxyphenanthrene (IIF), a ligand of retinoid X receptors, were investigated for their capability to interference with the cross-talk between breast CSCs and the niche compartment. We found that IIF potentiates the ability of PGZ to hamper the mammospheres-forming capability of human breast tumours and MCF7 cancer cells, reducing the expression of CSCs regulatory genes (Notch3, Jagged1, SLUG, Interleukin-6, Apolipoprotein E, Hypoxia inducible factor-1α and Carbonic anhydrase IX). Notably, these effects are not observed in normal-MS obtained from human breast tissue. Importantly, NRs agonists abolish the capability of hypoxic MCF7 derived exosomes to induce a pro-inflammatory phenotype in mammary glands fibroblasts. Moreover, NRs agonist also directly acts on breast tumour associated fibroblasts to downregulate nuclear factor-κB pathway and metalloproteinases (MMP2 and MMP9) expression and activity. In conclusion, NRs agonists disrupt the inflammatory cross-talk of the hypoxic breast CSCs niche. J. Cell. Physiol. 229: 1595-1606, 2014. © 2014 Wiley Periodicals, Inc.


Loi M.,CNR Institute of Molecular Genetics | Loi M.,Laboratory of Musculoskeletal Cell Biology | Cenni V.,CNR Institute of Molecular Genetics | Cenni V.,Laboratory of Musculoskeletal Cell Biology | And 10 more authors.
Oncotarget | Year: 2016

Chromatin disorganization is one of the major alterations linked to prelamin A processing impairment. In this study we demonstrate that BAF is necessary to modulate prelamin A effects on chromatin structure. We show that when prelamin A and BAF cannot properly interact no prelamin A-dependent effects on chromatin occur; similar to what is observed in human Nestor Guillermo Progeria Syndrome cells harboring a BAF mutation, in HEK293 cells expressing a BAF mutant unable to bind prelamin A, or in siRNA mediated BAF-depleted HEK293 cells expressing prelamin A. BAF is necessary to induce histone trimethyl-H3K9 as well as HP1-alpha and LAP2-alpha nuclear relocalization in response to prelamin A accumulation. These findings are enforced by electron microscopy evaluations showing how the prelamin A-BAF interaction governs overall chromatin organization. Finally, we demonstrate that the LAP2-alpha nuclear localization defect observed in HGPS cells involves the progerin-BAF interaction, thus establishing a functional link between BAF and prelamin A pathological forms.


Faenza I.,University of Bologna | Blalock W.,CNR Institute of Molecular Genetics | Bavelloni A.,Laboratory of Musculoskeletal Cell Biology | Schoser B.,Rizzoli Orthopaedic Institute | And 7 more authors.
FASEB Journal | Year: 2012

Phosphoinositide-phospholipase C β1 (PLCβ1) plays a crucial role in the initiation of the genetic program responsible for muscle differentiation. We previously demonstrated that nuclear PLCβ1 activates the cyclin D3 promoter during the differentiation of myoblasts to myotubes, indicating that PLCβ1 is essential for cyclin D3 promoter activation and gene transcription, through c-jun/AP1. Myotonic dystrophy (DM) is the most prevalent form of muscular dystrophy in adults. DM type 1 (DM1) and type 2 (DM2) are dominantly inherited multisystem disorders. DM1 is triggered by the pathological expansion of a (CTG)(n) triplet repeat in the gene coding for DMPK, the dystrophia myotonica-protein kinase, whereas a (CCTG)(n) tetranucleotide repeat expansion in the ZNF9 gene, encoding a CCHC-type zinc finger protein, causes DM2. We found that, unlike in normal myotubes, the level of expression of PLCβ1 in DM1 and DM2 cells was already elevated in proliferating cells. Treatment with insulin induced a dramatic decrease in the amount of PLCβ1. During differentiation, cyclin D3 and myogenin were elevated in normal myotubes, whereas differentiating DM1 and DM2 cells did not increase these proteins. Forced expression of PLCβ1 in DM1 and DM2 cells increased the expression of differentiation markers, myogenin and cyclin D3, and enhanced fusion of DM myoblasts. These results highlight again that PLCβ1 expression is a key player in myoblast differentiation, functioning as a positive regulator in the correction of delayed differentiation of skeletal muscle in DM human myoblasts. © FASEB.


Pellegrini C.,University of Ferrara | Zulian A.,University of Padua | Gualandi F.,University of Ferrara | Manzati E.,University of Ferrara | And 8 more authors.
Journal of Cellular Physiology | Year: 2013

Dystrophin is a subsarcolemmal protein that, by linking the actin cytoskeleton to the extracellular matrix via dystroglycans, is critical for the integrity of muscle fibers. Here, we report that epidermal melanocytes, obtained from conventional skin biopsy, express dystrophin with a restricted localization to the plasma membrane facing the dermal-epidermal junction. In addition the full-length muscle isoform mDp427 was clearly detectable in melanocyte cultures as assessed by immunohistochemistry, RNA, and Western blot analysis. Melanocytes of Duchenne muscular dystrophy (DMD) patients did not express dystrophin, and the ultrastructural analysis revealed typical mitochondrial alterations similar to those occurring in myoblasts from the same patients. Mitochondria of melanocytes from DMD patients readily accumulated tetramethylrhodamine methyl ester, indicating that they are energized irrespective of the presence of dystrophin but, at variance from mitochondria of control donors, depolarized upon the addition of oligomycin, suggesting that they are affected by a latent dysfunction unmasked by inhibition of the ATP synthase. Pure melanocyte cultures can be readily obtained by conventional skin biopsies and may be a feasible and reliable tool alternative to muscle biopsy for functional studies in dystrophinopathies. The mitochondrial dysfunction occurring in DMD melanocytes could represent a promising cellular biomarker for monitoring dystrophinopathies also in response to pharmacological treatments. © 2012 Wiley Periodicals, Inc.


Capanni C.,CNR Institute of Molecular Genetics | Squarzoni S.,CNR Institute of Molecular Genetics | Cenni V.,CNR Institute of Molecular Genetics | D'Apice M.R.,University of Rome Tor Vergata | And 7 more authors.
Cell Cycle | Year: 2012

Prelamin A processing impairment is a common feature of a restricted group of rare genetic alterations/disorders associated with a wide range of clinical phenotypes. Changes in histone posttranslational modifications, alterations in non-histone chromatin proteins and chromatin disorganization have been specifically linked to impairment of specific, distinct prelamin A processing steps, but the molecular mechanism involved in these processes is not yet understood . In this study, we show that the accumulation of wild-type prelamin A detected in restrictive dermopathy (RD), as well as the accumulation of mutated forms of prelamin A identified in familial partial lipodystrophy (FPLD) and mandibuloacral dysplasia (MADA), affect the nuclear localization of barrier-to-autointegration factor (BAF), a protein able to link lamin A precursor to chromatin remodeling functions. Our findings, in accordance with previously described results, support the hypothesis of a prelamin A involvement in BAF nuclear recruitment and suggest BAF-prelamin A complex as a protein platform usually activated in prelamin A-accumulating diseases. Finally, we demonstrate the involvement of the inner nuclear membrane protein emerin in the proper localization of BAF-prelamin A complex. © 2012 Landes Bioscience.


Cenni V.,CNR Institute of Molecular Genetics | Cenni V.,Laboratory of Musculoskeletal Cell Biology | Bavelloni A.,Laboratory of Musculoskeletal Cell Biology | Beretti F.,University of Modena and Reggio Emilia | And 9 more authors.
Molecular Biology of the Cell | Year: 2011

Activation of Akt-mediated signaling pathways is crucial for survival, differentiation, and regeneration of muscle cells. A proteomic-based search for novel substrates of Akt was therefore undertaken in C 2C 12 murine muscle cells exploiting protein characterization databases in combination with an anti-phospho-Akt substrate antibody. A Scansite database search predicted Ankrd2 (Ankyrin repeat domain protein 2, also known as ARPP) as a novel substrate of Akt. In vitro and in vivo studies confirmed that Akt phosphorylates Ankrd2 at Ser-99. Moreover, by kinase assay with recombinant Akt1 and Akt2, as well as by single-isoform silencing, we demonstrated that Ankrd2 is a specific substrate of Akt2. Ankrd2 is typically found in skeletal muscle cells, where it mediates the transcriptional response to stress conditions. In an attempt to investigate the physiological implications of Ankrd2 phosphorylation by Akt2, we found that oxidative stress induced by H 2O 2 triggers this phosphorylation. Moreover, the forced expression of a phosphorylation-defective mutant form of Ankrd2 in C 2C 12 myoblasts promoted a faster differentiation program, implicating Akt-dependent phosphorylation at Ser-99 in the negative regulation of myogenesis in response to stress conditions. © 2011 Cenni et al.


PubMed | Laboratory of Musculoskeletal Cell Biology
Type: Journal Article | Journal: European journal of histochemistry : EJH | Year: 2013

Mutations in genes encoding nuclear envelope proteins, particularly LMNA encoding the A-type lamins, cause a broad range of diverse diseases, referred to as laminopathies. The astonishing variety of diseased phenotypes suggests that different mechanisms could be involved in the pathogenesis of laminopathies. In this review we will focus mainly on two of these pathogenic mechanisms: the nuclear damages affecting the chromatin organization, and the oxidative stress causing un-repairable DNA damages. Alteration in the nuclear profile and in chromatin organization, which are particularly impressive in systemic laminopathies whose cells undergo premature senescence, are mainly due to accumulation of unprocessed prelamin A. The toxic effect of these molecular species, which interfere with chromatin-associated proteins, transcription factors, and signaling pathways, could be reduced by drugs which reduce their farnesylation and/or stability. In particular, inhibitors of farnesyl transferase (FTIs), have been proved to be active in rescuing the altered cellular phenotype, and statins, also in association with other drugs, have been included into pilot clinical trials. The identification of a mechanism that accounts for accumulation of un-repairable DNA damage due to reactive oxygen species (ROS) generation in laminopathic cells, similar to that found in other muscular dystrophies (MDs) caused by altered expression of extracellular matrix (ECM) components, suggests that anti-oxidant therapeutic strategies might prove beneficial to laminopathic patients.

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