Evidence of disrupted rhombic lip development in the pathogenesis of Dandy-Walker malformation.

Dandy-Walker malformation (DWM) and Cerebellar vermis hypoplasia (CVH) are commonly recognized human cerebellar malformations diagnosed following ultrasound and antenatal or postnatal MRI. Specific radiological criteria are used to distinguish them, yet little is known about their differential developmental disease mechanisms. We acquired prenatal cases diagnosed as DWM and CVH and studied cerebellar morphobiometry followed by histological and immunohistochemical analyses. This was supplemented by laser capture microdissection and RNA-sequencing of the cerebellar rhombic lip, a transient progenitor zone, to assess the altered transcriptome of DWM vs control samples. Our radiological findings confirm that the cases studied fall within the accepted biometric range of DWM. Our histopathological analysis points to reduced foliation and inferior vermian hypoplasia as common features in all examined DWM cases. We also find that the rhombic lip, a dorsal stem cell zone that drives the growth and maintenance of the posterior vermis is specifically disrupted in DWM, with reduced proliferation and self-renewal of the progenitor pool, and altered vasculature, all confirmed by transcriptomics analysis. We propose a unified model for the developmental pathogenesis of DWM. We hypothesize that rhombic lip development is disrupted through either aberrant vascularization and/or direct insult which causes reduced proliferation and failed expansion of the rhombic lip progenitor pool leading to disproportionate hypoplasia and dysplasia of the inferior vermis. Timing of insult to the developing rhombic lip (before or after 14 PCW) dictates the extent of hypoplasia and distinguishes DWM from CVH.

Characterization of autochthonous sweet cherry cultivars (Prunus avium L.) of southern Italy for fruit quality, bioactive compounds and antioxidant activity.

BACKGROUND: Characterizing germplasm collections of autochthonous cultivars for fruit quality traits could be a successful approach for selection, improvement of organoleptic quality and levels of antioxidants of crop produce, and development of new market opportunities and coherent strategies for conservation and valorization. The aim of the study was the evaluation of fruit physicochemical traits as well as the content of bioactive compounds and the antioxidant capacity in 25 sweet cherry autochthonous cultivars. RESULTS: Cultivars were a source of statistically significant variation for all evaluated traits. Notably, average fruit ascorbate levels ranged from 34.45 to 244.68 µg g-1 fresh weight (FW) , total flavonoids from 1396.40 to 4694.75 µg quercetin equiv. g-1 FW, monomeric anthocyanins from 4.80 to 360.90 µg g-1 FW, and total antioxidant capacity from 1.53 to 2.58 nmol Trolox equiv. mg-1 FW. Fruit profiling of eight cultivars by high-resolution mass spectrometry identified a total of eight different anthocyanins and twenty-five non-anthocyanin polyphenolic compounds - mostly coumaroylquinic acid and neochlorogenic acid. CONCLUSION: Among the better-performing cultivars for fruit quality traits, Mulegnana Nera and Pagliarella shared high fruit levels of phenolics, flavonoids and antioxidant capacity. This is a forerunner work on the characterization of genetic resources, which is critical to researchers and breeders for exploitation of the genetic potential of cultivars and for their conservation. © 2016 Society of Chemical Industry.

Chromosomal anomalies in early spontaneous abortions: interphase FISH analysis on 855 FFPE first trimester abortions.

OBJECTIVE: Cytogenetic analysis of spontaneous abortuses presents at least two main challenges, cell culture failure, and excess of normal female karyotypes related to maternal cell contamination (MCC). Molecular cytogenetic techniques using uncultured cell suspension overcome cell culture failure, but do not resolve MCC at all. The aim of the present study is to demonstrate that interphase fluorescence in situ hybridization (FISH) on routine formalin-fixed paraffin embedded (FFPE) abortive materials is an efficient method to identify chromosomal anomalies in abortuses and to detect MCC. METHOD: Interphase FISH with a panel of eight probes was applied on 855 FFPE consecutive early spontaneous abortions. RESULTS: Male/female ratio was 0.88 in the complete sample, 0.9 in the group of negative FISH result, and 0.8 in the group with abnormal FISH results, suggesting that no gender predominance was present in our data. The aneuploidy rate was 50.3%. Autosomal trisomies were 60%, polyploidies 23.2%, and X monosomy 14%. Chromosomal mosaicism was discovered in 1.9% with six cases of confined placental mosaicism. CONCLUSION: FISH on FFPE abortion materials appears to be a successful approach to detect chromosomal anomalies in abortions. Moreover, the preservation of the tissue morphology allows the analysis of only the fetal cells, making the presence of maternal tissues irrelevant.

New Role of Adult Lung c-kit+ Cells in a Mouse Model of Airway Hyperresponsiveness.

Structural changes contribute to airway hyperresponsiveness and airflow obstruction in asthma. Emerging evidence points to the involvement of c-kit+ cells in lung homeostasis, although their potential role in asthma is unknown. Our aim was to isolate c-kit+ cells from normal mouse lungs and to test whether these cells can interfere with hallmarks of asthma in an animal model. Adult mouse GFP-tagged c-kit+ cells, intratracheally delivered in the ovalbumin-induced airway hyperresponsiveness, positively affected airway remodeling and improved airway function. In bronchoalveolar lavage fluid of cell-treated animals, a reduction in the number of inflammatory cells and in IL-4, IL-5, and IL-13 release, along with an increase of IL-10, was observed. In MSC-treated mice, the macrophage polarization to M2-like subset may explain, at least in part, the increment in the level of anti-inflammatory cytokine IL-10. After in vitro stimulation of c-kit+ cells with proinflammatory cytokines, the indoleamine 2,3-dioxygenase and TGFß were upregulated. These data, together with the increased apoptosis of inflammatory cells in vivo, indicate that c-kit+ cells downregulate immune response in asthma by influencing local environment, possibly by cell-to-cell contact combined to paracrine action. In conclusion, intratracheally administered c-kit+ cells reduce inflammation, positively modulate airway remodeling, and improve function. These data document previously unrecognized properties of c-kit+ cells, able to impede pathophysiological features of experimental airway hyperresponsiveness.

Doxorubicin induces senescence and impairs function of human cardiac progenitor cells.

The increasing population of cancer survivors faces considerable morbidity and mortality due to late effects of the antineoplastic therapy. Cardiotoxicity is a major limiting factor of therapy with doxorubicin (DOXO), the most effective anthracycline, and is characterized by a dilated cardiomyopathy that can develop even years after treatment. Studies in animals have proposed the cardiac progenitor cells (CPCs) as the cellular target responsible for DOXO-induced cardiomyopathy but the relevance of these observations to clinical settings is unknown. In this study, the analysis of the DOXO-induced cardiomyopathic human hearts showed that the majority of human CPCs (hCPCs) was senescent. In isolated hCPCs, DOXO triggered DNA damage response leading to apoptosis early after exposure, and telomere shortening and senescence at later time interval. Functional properties of hCPCs, such as migration and differentiation, were also negatively affected. Importantly, the differentiated progeny of DOXO-treated hCPCs prematurely expressed the senescence marker p16(INK4a). In conclusion, DOXO exposure severely affects the population of hCPCs and permanently impairs their function. Premature senescence of hCPCs and their progeny can be responsible for the decline in the regenerative capacity of the heart and may represent the cellular basis of DOXO-induced cardiomyopathy in humans.

Impact of the MTHFR C677T polymorphism on risk of Wilms tumor: case-control study.

Methylentetrahydrofolate reductase C677T genotype was assessed in 35 patients of both sexes aged between 3.2 and 5.4 years affected by Wilms tumor (WT) and in 70 random controls. Statistical analysis was performed comparing frequency of WT methylentetrahydrofolate reductase genotypes with 70 controls and a larger Italian population. The homozygous TT and heterozygous CT genotypes were associated with a significantly higher frequency of WT than CC genotype. By reducing tissue folate concentrations and inducing hypomethylation both TT and CT genotypes could be risk factors for WT (odds ratio >1).

Role of polysomy 17 in transitional cell carcinoma of the bladder: immunohistochemical study of HER2/neu expression and fish analysis of c-erbB-2 gene and chromosome 17.

This study investigates the potential clinical significance of c-erbB-2 gene and chromosome 17 alterations by fluorescence in situ hybridization (FISH) analysis and HER2/neu overexpression by immunohistochemical staining in transitional cell carcinoma (TCC) of urinary bladder correlating the results with tumor stage and grade categories and with clinical behavior. Sixty-three cases of TCC retrieved from the files of 2 institutions were analyzed for chromosome 17 aberrations and c-erbB-2 amplification by FISH analysis and evaluated immunohistochemically for HER2/neu overexpression. Five tumors were G1, 29 intermediate grade (G2), and 29 tumors high grade (G3); 32 tumors had stage Ta, 18 tumors T1, and 13 tumors T2. We found polysomy of chromosome 17 in 58.7% of TCC with average chromosome copy number >2.26; increased number of HER2/neu gene copy was observed in 66.7% of tumors. C-erbB-2 amplification occurred in 6.3% of tumors. Immunohistochemically, 60.3% of TCC overexpressed HER2/neu and 39.7% of tumors were negative. All tumors with polysomy showed simultaneously increase of HER2/neu gene copy number of which 34/37 with protein overexpression. A statistically significant correlation between polysomy of chromosome 17 and tumor stage (P = .0003) and tumor grade (P < .0001) was found; polysomy was not seen in G1 tumors; however, 8/29 G2 tumors and 29/29 G3 tumors revealed polysomy of chromosome 17; in 8/32 Ta tumors, 14/18 T1 and 13/13 of deeply invasive tumors (T2) polysomy 17 was observed. Moreover, it was found that 7 superficial tumors (1 Ta and 6 T1) showed high polysomy with average of chromosome 17 copy number > or =3.76 as observed in all invasive tumors. The data suggest that although HER2/neu amplification, found in high grade and invasive tumors, is a rare event in TCC, polysomy of chromosome 17 is an important factor correlated with tumor stage and grade categories and could be considered a molecular marker of tumor progression with interesting diagnostic implications.

Modified Roux-Goldthwait Procedure for Management of Patellar Dislocation in Skeletally Immature Patients with Down Syndrome.

BACKGROUND: Patellar instability is a common problem in Down syndrome patients since their childhood. Several treatment have been proposed, but relapses are frequent and not all surgeries are suitable for growing patients. The aim of the present study is to evaluate the clinical and radiographic outcomes of a modified Roux-Goldthwait technique, for the management of patellar instability in children with Down syndrome at minimum 5-year followup. MATERIALS AND METHODS: 19 patients (23 knees) affected by Down syndrome surgically treated for patellar dislocation, between 2000 and 2012 were included in this study. The mean age of patients was 9.5 years (range 3.7 - 15 years) and had a Dugdale Grade III, IV, and V patellar dislocation. Trochlear groove dysplasia was present in 15 patients. Each patient was clinically evaluated considering relapse rate, pre- and postoperative range of motion (ROM), Kujala score, and modified Lysholm score. Radiographic examination was performed on standard X-ray considering patellar height, trochlear angle, and patellofemoral congruence angle. RESULTS: The mean followup was 134 months (range 62-206 months). No case of relapse of dislocation was registered with an improved ROM (significant for knee extension, P < 0.05). The Kujala score showed significant improvement from a mean preoperative value of 39 ± 6.3 to a mean postoperative value of 92.7 ± 3.4 (P < 0.05) at final followup such as the modified Lysholm score (from mean preoperative 55.6 ± 6.3 to mean postoperative of 94.2 ± 2.6). Radiographs performed at latest followup showed a tendency to normalization of all the parameters considered, with a restored patellofemoral congruence and trochlear groove shape and without signs of osteoarthritis. CONCLUSION: The present study showed that the Roux-Goldthwait procedure is a valid surgical option for the treatment of patellar dislocation in children with Down syndrome.

Double hindfoot arthrodesis technique for the treatment of severe equino-plano-valgus foot deformity in cerebral palsy: long-term results and radiological evaluation.

The aim of this study was to evaluate the clinical and radiological results of a double arthrodesis technique for the treatment of equino-plano-valgus foot deformity in pediatric patients affected by cerebral palsy. A retrospective evaluation was performed on 175 feet surgically treated with a talonavicular and calcaneocuboid joint fusion technique. The average age at surgery was 14.7 years (range: 12-20 years). Visual analogue scale for pain score, Gross Motor Function Classification System scale, talonavicular angle, Costa-Bertani angle, and Kite's angle on standard weight bearing radiographs were evaluated preoperatively and postoperatively. The mean clinical follow-up was 62.4 months (range: 12-112 months). The mid Gross Motor Function Classification System scale value did not show a significant improvement in any of the subgroups considered. A significant improvement in the visual analogue scale for pain score value was evident 6 months after surgery. Radiological examination showed a statistically significant improvement in the talonavicular angle (average 7.4°) and the Costa-Bertani angle (average 128.5°). Complications occurred in 8.6% of cases. The described surgical technique is safe and efficacious, and could represent a useful option of treatment of equino-plano-valgus severe deformity in cerebral palsy patients older than 12 years of age.

Spatiotemporal expansion of primary progenitor zones in the developing human cerebellum.

We present histological and molecular analyses of the developing human cerebellum from 30 days after conception to 9 months after birth. Differences in developmental patterns between humans and mice include spatiotemporal expansion of both ventricular and rhombic lip primary progenitor zones to include subventricular zones containing basal progenitors. The human rhombic lip persists longer through cerebellar development than in the mouse and undergoes morphological changes to form a progenitor pool in the posterior lobule, which is not seen in other organisms, not even in the nonhuman primate the macaque. Disruptions in human rhombic lip development are associated with posterior cerebellar vermis hypoplasia and Dandy-Walker malformation. The presence of these species-specific neural progenitor populations refines our insight into human cerebellar developmental disorders.

Fluorescent in situ hybridization as a screening test for HER2 amplification in G2 and G3 breast cancers of lobular and ductal histotype and metastases.

The aim of the present study was to evaluate the effectiveness of fluorescence in situ hybridisation (FISH), as a screening test, in moderately- (G2) or poorly- (G3) differentiated breast cancers of the ductal (IDC) and lobular (ILC) histotypes and distant metastases. HER2 FISH was performed on 486 G2 and 477 G3 both of IDC and ILC histotypes and in 241 metastases. A significant difference in the HER2 amplification was observed between G2 (14.8%) and G3 (31.9%), with no difference according to the histotype. However, the rate of amplification increased to 36% in the G2/hormone receptor-negative cases as compared to 10.6% in the G2/receptor-positive cases (p<0.0001). HER2 was amplified in 17% of metastases with some differences depending on the location. These data suggest that the HER2 FISH analysis may be an effective screening test in breast cancer metastases and G3 tumors, irrespective of the hormone receptor status or presence of lymphovascular invasion.

Long-term remission in BCR/ABL-positive AML-M6 patient treated with Imatinib Mesylate.

BCR/ABL-positive acute myeloid leukemia (AML) is a rare disease, characterized by a poor prognosis, with resistance to induction chemotherapy and frequent relapses in responsive patients. Here we report a case of BCR/ABL-positive AML-M6 who, after relapse, was treated with Imatinib Mesylate (600 mg/die) and within 4 months achieved a cytogenetic and molecular complete response. After more than 4 years of continuous Imatinib therapy, nested RT-PCR for BCR/ABL is persistently negative. The case reported shows that the response obtained with Imatinib Mesylate in BCR/ABL-positive AML may be long lasting, offering a chance of successful treatment for this poor prognosis group of patients.

Isolated posterior cerebellar vermal defect: a morphological study of midsagittal cerebellar vermis in 4 fetuses--early stage of Dandy-Walker continuum or new vermal dysgenesis?

This report is a neuropathological description of posterior cerebellar vermis agenesis/hypoplasia at midgestation. This defect was demonstrated by prenatal ultrasound in four 21- to 24-week-old fetuses. Neuropathological findings were characterized macroscopically by hypoplasia of the posterior vermis with normal cerebellar hemispheres and brainstem; hypoplasia of the posterior vermian lobules 6 to 10, mildly cystic dilatation of the ventricular cavity, and a flat profile of the roof of the fourth ventricle also were demonstrated. Microscopically, a hypercellular and abnormally located germinal matrix and abnormal migration of external granule cell precursors into the meningeal tissue above the outer surface of the cerebellum were found. These abnormalities might result in delayed growth and foliation of the posterior vermian lobules. This feature might be the neuropathological pattern of the early stage of the Dandy-Walker continuum, although it cannot be excluded as a consequence of a primary developmental failure of the vermal primordium.

Sitagliptin reduces inflammation, fibrosis and preserves diastolic function in a rat model of heart failure with preserved ejection fraction.

BACKGROUND AND PURPOSE: Heart failure with preserved ejection fraction (HFpEF) is a systemic syndrome driven by co-morbidities, and its pathophysiology is poorly understood. Several studies suggesting that dipeptidyl peptidase 4 (DPP4) might be involved in the pathophysiology of heart failure have prompted experimental and clinical investigations of DPP4 inhibitors in the cardiovascular system. Here we have investigated whether the DPP4 inhibitor sitagliptin affected the progression of HFpEF independently of its effects on glycaemia. EXPERIMENTAL APPROACH: Seven-week-old Dahl salt-sensitive rats were fed a high-salt diet for 5 weeks to induce hypertension. Then the rats continued with the high-salt diet and were treated with either sitagliptin (10 mg·kg-1 ) or vehicle for the following 8 weeks. Blood pressure and cardiac function were measured in vivo. Histochemical and molecular biology analyses of myocardium were used to assay cytokines, fibrotic markers, DPP4 and glucagon-like peptide-1 (GLP-1)/GLP-1 receptor. KEY RESULTS: Treatment with sitagliptin attenuated diastolic dysfunction, reduced mortality and reduced cardiac DPP4 activity, along with increased circulating GLP-1 and myocardial expression of GLP-1 receptors. Myocardial levels of pro-inflammatory cytokines (TNF-α, IL-6 and CCL2) were reduced. Sitagliptin treatment decreased the levels of endothelial NOS monomer, responsible for generation of ROS, while the amount of NO-producing dimeric form increased. Markers of oxidative and nitrosative stress were decreased. Moreover, increased collagen deposition and activation of pro-fibrotic signalling, inducing elevated myocardial stiffness, were attenuated by sitagliptin treatment. CONCLUSIONS AND IMPLICATIONS: Sitagliptin positively modulated active relaxation and passive diastolic compliance by decreasing inflammation-related endothelial dysfunction and fibrosis, associated with HFpEF. LINKED ARTICLES: This article is part of a themed section on Targeting Inflammation to Reduce Cardiovascular Disease Risk. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v174.22/issuetoc and http://onlinelibrary.wiley.com/doi/10.1111/bcp.v82.4/issuetoc.

Phenotypic outcomes in Mouse and Human Foxc1 dependent Dandy-Walker cerebellar malformation suggest shared mechanisms.

FOXC1 loss contributes to Dandy-Walker malformation (DWM), a common human cerebellar malformation. Previously, we found that complete Foxc1 loss leads to aberrations in proliferation, neuronal differentiation and migration in the embryonic mouse cerebellum (Haldipur et al., 2014). We now demonstrate that hypomorphic Foxc1 mutant mice have granule and Purkinje cell abnormalities causing subsequent disruptions in postnatal cerebellar foliation and lamination. Particularly striking is the presence of a partially formed posterior lobule which echoes the posterior vermis DW 'tail sign' observed in human imaging studies. Lineage tracing experiments in Foxc1 mutant mouse cerebella indicate that aberrant migration of granule cell progenitors destined to form the posterior-most lobule causes this unique phenotype. Analyses of rare human del chr 6p25 fetal cerebella demonstrate extensive phenotypic overlap with our Foxc1 mutant mouse models, validating our DWM models and demonstrating that many key mechanisms controlling cerebellar development are likely conserved between mouse and human.

Effects of ranolazine in a model of doxorubicin-induced left ventricle diastolic dysfunction.

BACKGROUND AND PURPOSE: Doxorubicin is a highly effective anticancer drug, but its clinical application is hampered by cardiotoxicity. Asymptomatic diastolic dysfunction can be the earliest manifestation of doxorubicin cardiotoxicity. Therefore, a search for therapeutic intervention that can interfere with early manifestations and possibly prevent later development of cardiotoxicity is warranted. Increased doxorubicin-dependent ROS may explain, in part, Ca2+ and Na+ overload that contributes to diastolic dysfunction and development of heart failure. Therefore, we tested whether the administration of ranolazine, a selective blocker of late Na+ current, immediately after completing doxorubicin therapy, could affect diastolic dysfunction and interfere with the progression of functional decline. EXPERIMENTAL APPROACH: Fischer 344 rats received a cumulative dose of doxorubicin of 15 mg·kg-1 over a period of 2 weeks. After the assessment of diastolic dysfunction, the animals were treated with ranolazine (80 mg·kg-1 , daily) for the following 4 weeks. KEY RESULTS: While diastolic and systolic function progressively deteriorated in doxorubicin-treated animals, treatment with ranolazine relieved diastolic dysfunction and prevented worsening of systolic function, decreasing mortality. Ranolazine lowered myocardial NADPH oxidase 2 expression and oxidative/nitrative stress. Expression of the Na+ /Ca2+ exchanger 1 and Nav 1.5 channels was reduced and of the sarcoplasmic/endoplasmic reticulum Ca2+ -ATPase 2 protein was increased. In addition, ranolazine lowered doxorubicin-induced hyper-phosphorylation and oxidation of Ca2+ /calmodulin-dependent protein kinase II, and decreased myocardial fibrosis. CONCLUSIONS AND IMPLICATIONS: Ranolazine, by the increased Na+ influx, induced by doxorubicin, altered cardiac Ca2+ and Na+ handling and attenuated diastolic dysfunction induced by doxorubicin, thus preventing the progression of cardiomyopathy. LINKED ARTICLES: This article is part of a themed section on New Insights into Cardiotoxicity Caused by Chemotherapeutic Agents. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v174.21/issuetoc.

Medicinal plants with anti-inflammatory activities.

Medicinal plants have been the main remedy to treat various ailments for a long time and nowadays, many drugs have been developed from traditional medicine. This paper reviews some medicinal plants and their main constituents which possess anti-inflammatory activities useful for curing joint inflammation, inflammatory skin disorders, cardiovascular inflammation and other inflammatory diseases. Here, we provide a brief overview of quick and easy reading on the role of medicinal plants and their main constituents in these inflammatory diseases. We hope that this overview will shed some light on the function of these natural anti-inflammatory compounds and attract the interest of investigators aiming at the design of novel therapeutic approaches for the treatment of various inflammatory conditions.

MicroRNA-34a regulates doxorubicin-induced cardiotoxicity in rat.

New strategies to prevent and early detect the cardiotoxic effects of the anticancer drug doxorubicin (DOXO) are required. MicroRNAs emerged as potential diagnostic, therapeutic and prognostic approaches in cardiovascular diseases. MiR-34a has a role in cardiac dysfunction and ageing and is involved in several cellular processes associated with DOXO cardiotoxicity. Our in vitro and in vivo results indicated that after DOXO exposure the levels of miR-34a are enhanced in cardiac cells, including Cardiac Progenitor Cells (CPCs). Since one of the determining event responsible for the initiation and evolution of the DOXO toxicity arises at the level of the CPC compartment, we evaluated if miR-34a pharmacological inhibition in these cells ameliorates the detrimental aftermath of the drug. AntimiR-34a has beneficial consequences on vitality, proliferation, apoptosis and senescence of DOXO-treated rat CPC. These effects are mediated by an increase of prosurvival miR-34a targets Bcl-2 and SIRT1, accompanied by a decrease of acetylated-p53 and p16INK4a. Importantly, miR-34a silencing also reduces the release of this miRNA from DOXO-exposed rCPCs, decreasing its negative paracrine effects on other rat cardiac cells. In conclusion, the silencing of miR-34a could represent a future therapeutic option for cardioprotection in DOXO toxicity and at the same time, it could be considered as a circulating biomarker for anthracycline-induced cardiac damage.

SIRT1 activation attenuates diastolic dysfunction by reducing cardiac fibrosis in a model of anthracycline cardiomyopathy.

BACKGROUND: Doxorubicin (DOXO) is an effective anti-neoplastic drug but its clinical benefits are hampered by cardiotoxicity. Oxidative stress, apoptosis and myocardial fibrosis mediate the anthracycline cardiomyopathy. ROS trigger TGF-ß pathway that activates cardiac fibroblasts promoting fibrosis. Myocardial stiffness contributes to diastolic dysfunction, less studied aspect of anthracycline cardiomyopathy. Considering the role of SIRT1 in the inhibition of the TGF-ß/SMAD3 pathway, resveratrol (RES), a SIRT1 activator, might improve cardiac function by interfering with the development of cardiac fibrosis in a model of DOXO-induced cardiomyopathy. METHODS: F344 rats received a cumulative dose of 15 mg/kg of DOXO in 2 weeks or DOXO+RES (DOXO and RES, 2.5mg/kg/day, concomitantly for 2 weeks and then RES alone for 1 more week). The effects of RES on cardiac fibroblasts were also tested in vitro. RESULTS: Along with systolic dysfunction, DOXO was also responsible of diastolic abnormalities. Myocardial stiffness correlated with fibroblast activation and collagen deposition. DOXO+RES co-treatment significantly improved ± dP/dt and, more interestingly, ameliorated end-diastolic pressure/volume relationship. Treatment with RES resulted in reduced fibrosis and fibroblast activation and, most importantly, the mortality rate was significantly reduced in DOXO+RES group. Fibroblasts isolated from DOXO+RES-treated rats, in which SIRT1 was upregulated, showed decreased levels of TGF-ß and pSMAD3/SMAD3 when compared to cells isolated from DOXO-exposed hearts. CONCLUSIONS: Our findings reveal a key role of SIRT1 in supporting animal survival and functional parameters of the heart. SIRT1 activation by interfering with fibrogenesis can improve relaxation properties of myocardium and attenuate myocardial remodeling related to chemotherapy.

Doxorubicin cardiotoxicity and target cells: a broader perspective.

The cardiotoxicity of doxorubicin is becoming an interdisciplinary point of interest given a growing population of cancer survivors. The complex and not completely understood pathogenesis of this complication makes difficult to design successful preventive or curative measures. Although cardiomyocyte has been considered a classical cellular target, other cells including various types of undifferentiated cells are involved in myocardial homeostasis. Such perspective may shed light on previously unrecognized aspects of cardiotoxicity and promote new experimental and clinical cardioprotective strategies. In this review, different cellular targets of doxorubicin are discussed with the focus on cardiac progenitor cells, oxidative stress, DNA damage, senescence and apoptosis all of which contribute to their compromised functional properties.