DNA content and expression of cell cycle proteins in caterpillar nuclei from fetal human cardiac myocytes

Caterpillar nuclei (CN) are characterized by their peculiar morphology, with chromatin distributed in clusters and running along the longitudinal axis of the nucleus. They can be observed in normal hearts of fetuses as well as in hearts of children and adults with rheumatic heart disease. This study has demonstrated by means of ploidy studies with digital image analysis that in the fetal heart (20.5±1.8 weeks) the CN (diploid = 5.6±8.4%; tetraploid = 46.2±24.2%; hypertetraploid = 46.9±26.3%) present higher DNA content than non-caterpillar myocyte nuclei (diploid = 89.4±6.2%; tetraploid = 10.0±4.1%; hypertetraploid = 1.5±1.3%) (P=0.000001, 0.00013, and 0.000038, respectively). Expression of proliferation cell nuclear antigen (PCNA; 30.6±11.7% in CN and 13.4±7.3% in non-caterpillar myocyte nuclei; P=0.0115) and cyclin B1 (2.8±3.8% and 12.6±15.6%, respectively; P=n.s.) was also positive in these nuclei. In conclusion, these results suggest that there exists a relationship between CN morphology and myocyte replication phenomena.Universidad Nacional de La Plat

Doxorubicin and NRG-1/erbB4-Deficiency Affect Gene Expression Profile: Involving Protein Homeostasis in Mouse

The accumulating evidence demonstrates the essential role of neuregulin-1 signaling in the adult heart, and, moreover, indicates that an impaired neuregulin signaling exacerbates the doxorubicin-mediated cardiac toxicity. Despite this strong data, the specific cardiomyocyte targets of the active erbB2/erbB4 heterodimer remain unknown. In this paper, we examined pathways involved in cardiomyocyte damage as a result of the cardiac sensitization to anthracycline toxicity in the ventricular muscle-specific erbB4 knockout mouse. We performed morphological analyses to evaluate the ventricular remodeling and employed a cDNA microarray to assess the characteristic gene expression profile, verified data by real-time RT-PCR, and then grouped into functional categories and pathways. We confirm the upregulation of genes related to the classical signature of a hypertrophic response, implicating an erbB2-dependent mechanism in doxorubicin-treated erbB4-KO hearts. Our results indicate the remarkable downregulation of IGF-I/PI-3′ kinase pathway and extends our current knowledge by uncovering an altered ubiquitin-proteasome system leading to cardiomyocyte autophagic vacuolization.Centro de Investigaciones Cardiovasculare

Histidine-Rich Glycoprotein Inhibits HIV-1 Infection in a pH-Dependent Manner

Histidine-rich glycoprotein (HRG) is an abundant plasma protein with a multidomain structure, allowing its interaction with many ligands, including phospholipids, plasminogen, fibrinogen, IgG antibodies, and heparan sulfate. HRG has been shown to regulate different biological responses, such as angiogenesis, coagulation, and fibrinolysis. Here, we found that HRG almost completely abrogated the infection of Ghost cells, Jurkat cells, CD4+ T cells, and macrophages by HIV-1 at a low pH (range, 6.5 to 5.5) but not at a neutral pH. HRG was shown to interact with the heparan sulfate expressed by target cells, inhibiting an early postbinding step associated with HIV-1 infection. More importantly, by acting on the viral particle itself, HRG induced a deleterious effect, which reduces viral infectivity. Because cervicovaginal secretions in healthy women show low pH values, even after semen deposition, our observations suggest that HRG might represent a constitutive defense mechanism in the vaginal mucosa. Of note, low pH also enabled HRG to inhibit the infection of HEp-2 cells and Vero cells by respiratory syncytial virus (RSV) and herpes simplex virus 2 (HSV-2), respectively, suggesting that HRG might display broad antiviral activity under acidic conditions.Fil: Dantas, Ezequiel Carlos. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas en Retrovirus y Sida. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Biomédicas en Retrovirus y Sida; ArgentinaFil: Díaz, Fernando Erra. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas en Retrovirus y Sida. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Biomédicas en Retrovirus y Sida; ArgentinaFil: Pereyra Gerber, Federico Pehuén. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas en Retrovirus y Sida. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Biomédicas en Retrovirus y Sida; ArgentinaFil: Varese, Augusto. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas en Retrovirus y Sida. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Biomédicas en Retrovirus y Sida; ArgentinaFil: Jerusalinsky, Diana Alicia. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Biología Celular y Neurociencia "Prof. Eduardo de Robertis". Universidad de Buenos Aires. Facultad de Medicina. Instituto de Biología Celular y Neurociencia; ArgentinaFil: Epstein, Alberto Luis. Université de Versailles Saint-quentin-en-yvelines.; Francia. Inserm; FranciaFil: García Rivello, Hernán J.. Hospital Italiano. Instituto Universitario. Escuela de Medicina; ArgentinaFil: del Valle Jaén, Ana. Hospital Italiano. Instituto Universitario. Escuela de Medicina; ArgentinaFil: Pandolfi, Julieta Belen. Hospital Italiano. Instituto Universitario. Escuela de Medicina; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Ceballos, Ana. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas en Retrovirus y Sida. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Biomédicas en Retrovirus y Sida; ArgentinaFil: Ostrowski, Matias. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas en Retrovirus y Sida. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Biomédicas en Retrovirus y Sida; ArgentinaFil: Sabatté, Juan. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas en Retrovirus y Sida. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Biomédicas en Retrovirus y Sida; ArgentinaFil: Geffner, Jorge Raúl. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas en Retrovirus y Sida. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Biomédicas en Retrovirus y Sida; Argentin

Cardiomyogenic differentiation of bone marrow mesenchymal cells: role of cardiac extract from neonatal rat cardiomyocytes

Bone marrow mesenchymal stromal cells (BM-MSCs) with regenerative potential have been identified in heart. Whether these cells become new cardiac lineage cells by phenomena of transdifferentiation or fusion is also being investigated. Although, these mechanisms give cardiomyocytes, it has to be considered that MSCs transplantation could carry out ossification and calcification processes. An alternative might be the use of myocytes; however, the problem is the arrythmia. For those reasons, is that we investigated how to obtain cardiomyocyte-like cells from human MSCs (hMSCs). The aim of the present work was to evaluate a nuclear reprogramming of the hMSCs by a neonatal rat cardiomyocytes extract (EX) using Streptolysin O (SLO) treatment. hMSCs treated with 57.5ng/ml SLO presented ball-like, stick-like and myotube-like morphology. In the absence of cardiomyogenic stimuli, hMSCs expressed markers of cardiac phenotype-like sarcomeric alpha-actinin, connexin-43 and GATA-4. However, when hMSCs were treated with SLO+EX or 10muM of 5-azacytidine (5-AZA), the expression of these markers were significantly increased and furthermore, expressed SERCA-2, cardiac Troponin I, beta-MyHC, desmin, MLC-2a and MLC-2v thus showing the phenotype of mature cardiomyocytes. PCR analysis showed that cardiomyocyte-related genes, such as beta1-adrenergic receptor (beta1-AR), MLC-2a and cardiac Troponin T, were expressed after SLO+EX treatment like with 5-AZA. We concluded that the extract of neonatal rat cardiomyocytes could promote a nuclear modification of hMSCs to cardiomyogenic-like cells differentiation. Since the 5-AZA treatment appears to be genotoxic and taking into account the obtained results, the nuclear reprogramming by cell extract may be an approach leading to the identification of soluble factors that drives the reprogramming.Fil: Labovsky, Vivian. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental (i); Argentina; ArgentinaFil: Hofer, E. L.. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental (i); Argentina; ArgentinaFil: Feldman, L.. Fundacion Favaloro; ArgentinaFil: Fernández Vallone, Valeria Beatriz. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental (i); Argentina; ArgentinaFil: García Rivello, Hernán. Hospital Italiano de Buenos Aires; ArgentinaFil: Bayes Genis, A.. Hospital de la Santa Creu I Sant Pau; EspañaFil: Hernando Insúa, A.. Immunotech S.a.; ArgentinaFil: Levin, Mariano Jorge. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones En Ingeniería Genética y Biología Molecular; ArgentinaFil: Chasseing, Norma Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental (i); Argentina; Argentin

Altered mRNA Expression of Telomere-Associated Genes in Monoclonal Gammopathy of Undetermined Significance and Multiple Myeloma

In this study, we explored changes in the expression of the telomere maintenance genes, TRF1, TRF2 and TANK1 in patients with monoclonal gammopathy of undetermined significance (MGUS) and multiple myeloma (MM). Results were correlated with human telomerase reverse transcriptase (hTERT ) expression, telomere length (TL) and clinicopathological characteristics. Bone marrow (BM) samples from 132 patients, 64 with MGUS and 68 with MM, were studied. Real-time quantitative reverse transcription–polymerase chain reaction was used to quantify gene expression. TL was evaluated by terminal restriction fragment length analysis. MGUS patients showed increased TRF1 levels (P = 0.006) and lower expression of TRF2 (P = 0.005) and TANK1 (P = 0.003) compared with MM patients. For hTERT analysis, patients were divided into three groups by use of receiver operating characteristics: low (group I [GI]), intermediate (group II [GII]) and high (group III [GIII]) expression. We observed increasing expression of TRF2 and TANK1 from GI to GIII in MGUS and MM, with differences for both genes in MM (P < 0.01) and for TRF2 in MGUS (P < 0.01). GIII patients with the highest telomerase expression had the shortest TL. In both entities, a positive association between TRF2-TANK1, TRF2-hTERT and TANK1-hTERT (P ≤ 0.01) was observed. In MM, the percentage of BM infiltration and Ki-67 index were positively associated with TRF2, TANK1 and hTERT expression (P ≤ 0.03) and negatively with TL (P = 0.02), whereas lactate dehydrogenase was significantly correlated with TRF2 mRNA (P = 0.008). Our findings provide the first evidence of a modification in the expression of telomeric proteins in plasma cell disorders, and suggest that mechanisms other than telomerase activation are involved in TL maintenance in these pathologies