Empagliflozin prevents doxorubicin-induced myocardial dysfunction.

BACKGROUND: Empagliflozin showed efficacy in controlling glycaemia, leading to reductions in HbA1c levels, weight loss and blood pressure, compared to standard treatment. Moreover, the EMPA-REG OUTCOME trial demonstrated a 14% reduction of major adverse cardiovascular events (MACE), a 38% reduction in cardiovascular (CV) death and a 35% reduction in the hospitalization rate for heart failure (HF). These beneficial effect on HF were apparently independent from glucose control. However, no mechanistic in vivo studies are available to explain these results, yet. We aimed to determine the effect of empagliflozin on left ventricular (LV) function in a mouse model of doxorubicin-induced cardiomyopathy (DOX-HF). METHODS: Male C57Bl/6 mice were randomly assigned to the following groups: controls (CTRL, n = 7), doxorubicin (DOX, n = 14), DOX plus empagliflozin (DOX + EMPA, n = 14), or DOX plus furosemide (DOX + FURO group, n = 7). DOX was injected intraperitoneally. LV function was evaluated at baseline and after 6 weeks of treatment using high-resolution echocardiography with 2D speckle tracking (Vevo 2100). Histological assessment was obtained using Haematoxylin and Eosin and Masson's Goldner staining. RESULTS: A significant decrease in both systolic and diastolic LV function was observed after 6 weeks of treatment with doxorubicin. EF dropped by 32% (p = 0.002), while the LS was reduced by 42% (p < 0.001) and the CS by 50% (p < 0.001). However, LV function was significantly better in the DOX + EMPA group, both in terms of EF (61.30 ± 11% vs. 49.24 ± 8%, p = 0.007), LS (- 17.52 ± 3% vs. - 13.93 ± 5%, p = 0.04) and CS (- 25.75 ± 6% vs. - 15.91 ± 6%, p < 0.001). Those results were not duplicated in the DOX + FURO group. Hearts from the DOX + EMPA group showed a 50% lower degree of myocardial fibrosis, compared to DOX mice (p = 0.03). No significant differences were found between the DOX + FURO and the DOX group (p = 0.103). CONCLUSION: Empagliflozin attenuates the cardiotoxic effects exerted by doxorubicin on LV function and remodelling in nondiabetic mice, independently of glycaemic control. These findings support the design of clinical studies to assess their relevance in a clinical setting.

Antisense Oligonucleotides and Small Interfering RNA for the Treatment of Dyslipidemias.

The burden of atherosclerotic disease worldwide necessitates implementing the treatment of its risk factors. Among them, hypercholesterolemia has a central role. In addition to conventional small organic compounds and the recently introduced monoclonal antibodies, new technologies are arising such as the antisense oligonucleotides and small interfering RNAs (siRNAs) that operate upstream, blocking the mRNA translation of the proteins specifically involved in lipid metabolism. In this review, we briefly explain the mechanisms of action of these molecules and discuss the difficulties related to their in vivo use as therapeutical agents. We go over the oligonucleotides tested in clinical trials that could potentially revolutionize the care of patients by acting on proteins involved in the lipoprotein metabolism and regulation, namely: angiopoietin-like protein 3 (ANGPTL3); lipoprotein a (Lp(a)); apolipoprotein B (Apo B); apolipoprotein C III (Apo C-III); and proprotein convertase subtilisin-kexin type 9 (PCSK9). Finally, the differences between ASOs and siRNAs, their future possible clinical applications, and the role of Inclisiran, a siRNA direct against PCSK9 to reduce LDL-C, were reviewed in detail.

Histone proteomics reveals novel post-translational modifications in breast cancer.

Histones and their variants are subjected to several post-translational modifications (PTMs). Histones PTMs play an important role in the regulation of gene expression and are critical for the development and progression of many types of cancer, including breast cancer. In this study, we used two-dimensional TAU/SDS electrophoresis, coupled with mass spectrometry for a comprehensive profiling of histone PTMs in breast cancer cell lines.Proteomic approach allowed us to identify 85 histone PTMs, seventeen of which are not reported in the UniProt database. Western blot analysis was performed to confirm a peculiar pattern of PTMs in the sporadic and hereditary breast cancer cell lines compared to normal cells. Overlapping mass spectrometry data with western blotting results, we identified, for the first time to our knowledge, a tyrosine phosphorylation on histone H1, which is significantly higher in breast cancer cells. Additionally, by inhibiting specific signaling paths, such as PI3K, PPARγ and FAK pathways, we established a correlation between their regulation and the presence of new histone PTMs. Our results may provide new insight on the possible implication of these modifications in breast cancer and may offer new perspectives for future clinical applications.

Unraveling the Mechanistic Complexity of the Glomerulocystic Phenotype in Dicer Conditional KO Mice by 2D Gel Electrophoresis Coupled Mass Spectrometry.

PURPOSE: Dicer, an RNase III type endonuclease, is a key enzyme involved in miRNA biogenesis. It has been shown that this enzyme is essential for several aspects of postnatal kidney functions and homeostasis. In this study, we have examined conditional knockout (cKO) mice for Dicer in Pax8 (Paired-box gene 8) expressing cells to investigate the kidney protein profile. This specific model develops a glomerulocystic phenotype coupled with urinary concentration impairment, proteinuria, and severe renal failure. EXPERIMENTAL DESIGN: Proteomic analysis was performed on kidney tissue extracts from cKO and control (Ctr) mice by 2D Gel Electrophoresis coupled with mass spectrometry. RESULTS: The analysis highlighted 120 protein spots differentially expressed in Dicer cKO tissue compared with control; some of these proteins were validated by Western blotting. Ingenuity Pathway Analysis led to the identification of some interesting networks; among them, the one having ERK as a central hub may explain, through the modulation of the expression of a number of identified protein targets, the metabolic and structural alterations occurring during kidney cyst development in Dicer cKO mouse model. CONCLUSIONS AND CLINICAL RELEVANCE: Our results contribute to gain new insights into molecular mechanisms through which Dicer endonuclease controls kidney development and physiological functions.

Proteomics Analysis to Assess the Role of Mitochondria in BRCA1-Mediated Breast Tumorigenesis.

Mitochondria are the organelles deputed to energy production, but they are also involved in carcinogenesis, cancer progression, and metastasis, playing a role in altered energy metabolism in cancer cells. Mitochondrial metabolism is connected with several mitochondrial pathways such as ROS signaling, Ca2+ homeostasis, mitophagy, and mitochondrial biogenesis. These pathways are merged in an interactive super-network that seems to play a crucial role in cancer. Germline mutations of the BRCA1 gene account for 5-10% of breast cancers and confer a risk of developing the disease 10- to 20-fold much higher than in non-carriers. By considering metabolic networks that could reconcile both genetic and non-genetic causal mechanisms in BRCA1 driven tumorigenesis, we herein based our study on the hypothesis that BRCA1 haploinsufficiency might drive metabolic rewiring in breast epithelial cells, acting as a push toward malignant transformation. Using 2D-DIGE we analyzed and compared the mitochondrial proteomic profile of sporadic breast cancer cell line (MCF7) and BRCA1 mutated breast cancer cell line (HCC1937). Image analysis was carried out with Decider Software, and proteins differentially expressed were identified by LC-MS/MS on a quadrupole-orbitrap mass spectrometer Q-Exactive. Ingenuity pathways analysis software was used to analyze the fifty-three mitochondrial proteins whose expression resulted significantly altered in response to BRCA1 mutation status. Mitochondrial Dysfunction and oxidative phosphorylation, and energy production and nucleic acid metabolism were, respectively, the canonical pathway and the molecular function mainly affected. Western blotting analysis was done to validate the expression and the peculiar mitochondrial compartmentalization of specific proteins such us HSP60 and HIF-1α. Particularly intriguing is the correlation between BRCA1 mutation status and HIF-1α localization into the mitochondria in a BRCA1 dependent manner. Data obtained led us to hypothesize an interesting connection between BRCA1 and mitochondria pathways, capable to trigger metabolic changes, which, in turn, sustain the high energetic and anabolic requirements of the malignant phenotype.

miRNA Regulation of the Hyperproliferative Phenotype of Vascular Smooth Muscle Cells in Diabetes.

Harnessing the mechanisms underlying the exacerbated vascular remodeling in diabetes mellitus (DM) is pivotal to prevent the high toll of vascular diseases in patients with DM. miRNA regulates vascular smooth muscle cell (VSMC) phenotypic switch. However, miRNA modulation of the detrimental diabetic VSMC phenotype is underexplored. Streptozotocin-induced type 1 DM (T1DM) Wistar rats and type 2 DM (T2DM) Zucker rats underwent right carotid artery experimental angioplasty, and global miRNA/mRNA expression profiling was obtained by RNA sequencing (RNA-Seq). Two days after injury, a set of six miRNAs were found to be uniquely downregulated or upregulated in VSMCs both in T1DM and T2DM. Among these miRNAs, miR-29c and miR-204 were the most significantly misregulated in atherosclerotic plaques from patients with DM. miR-29c overexpression and miR-204 inhibition per se attenuated VSMC phenotypic switch in DM. Concomitant miR-29c overexpression and miR-204 inhibition fostered an additive reduction in VSMC proliferation. Epithelial membrane protein 2 (Emp2) and Caveolin-1 (Cav1) mRNAs were identified as direct targets of miR-29c and miR-204, respectively. Importantly, contemporary miR-29c overexpression and miR-204 inhibition in the injured artery robustly reduced arterial stenosis in DM rats. Thus, contemporaneous miR-29c activation and miR-204 inhibition in DM arterial tissues is necessary and sufficient to prevent the exaggerated VSMC growth upon injury.

Hindlimb Ischemia Impairs Endothelial Recovery and Increases Neointimal Proliferation in the Carotid Artery.

Peripheral ischemia is associated with higher degree of endothelial dysfunction and a worse prognosis after percutaneous coronary interventions (PCI). However, the role of peripheral ischemia on vascular remodeling in remote districts remains poorly understood. Here we show that the presence of hindlimb ischemia significantly enhances neointima formation and impairs endothelial recovery in balloon-injured carotid arteries. Endothelial-derived microRNAs are involved in the modulation of these processes. Indeed, endothelial miR-16 is remarkably upregulated after vascular injury in the presences of hindlimb ischemia and exerts a negative effect on endothelial repair through the inhibition of RhoGDIα and nitric oxide (NO) production. We showed that the repression of RhoGDIα by means of miR-16 induces RhoA, with consequent reduction of NO bioavailability. Thus, hindlimb ischemia affects negative carotid remodeling increasing neointima formation after injury, while systemic antagonizzation of miR-16 is able to prevent these negative effects.

Integration of "Omics" Strategies for Biomarkers Discovery and for the Elucidation of Molecular Mechanisms Underlying Brugada Syndrome.

PURPOSE: The Brugada syndrome (BrS) is a severe inherited cardiac disorder. Given the high genetic and phenotypic heterogeneity of this disease, three different "omics" approaches are integrated in a synergic way to elucidate the molecular mechanisms underlying the pathophysiology of BrS as well as for identifying reliable diagnostic/prognostic markers. EXPERIMENTAL DESIGN: The profiling of plasma Proteome and MiRNome is perfomed in a cohort of Brugada patients that were preliminary subjected to genomic analysis to assess a peculiar gene mutation profile. RESULTS: The integrated analysis of "omics" data unveiled a cooperative activity of mutated genes, deregulated miRNAs and proteins in orchestrating transcriptional and post-translational events that are critical determining factors for the development of the Brugada pattern. CONCLUSIONS AND CLINICAL RELEVANCE: This study provides the basis to shed light on the specific molecular fingerprints underlying BrS development and to gain further insights on the pathogenesis of this life-threatening cardiac disease.

Plasma Proteomic Profiling in Hereditary Breast Cancer Reveals a BRCA1-Specific Signature: Diagnostic and Functional Implications.

BACKGROUND: Breast cancer (BC) is a leading cause of death among women. Among the major risk factors, an important role is played by familial history of BC. Germ-line mutations in BRCA1/2 genes account for most of the hereditary breast and/or ovarian cancers. Gene expression profiling studies have disclosed specific molecular signatures for BRCA1/2-related breast tumors as compared to sporadic cases, which might help diagnosis and clinical follow-up. Even though, a clear hallmark of BRCA1/2-positive BC is still lacking. Many diseases are correlated with quantitative changes of proteins in body fluids. Plasma potentially carries important information whose knowledge could help to improve early disease detection, prognosis, and response to therapeutic treatments. The aim of this study was to develop a comprehensive approach finalized to improve the recovery of specific biomarkers from plasma samples of subjects affected by hereditary BC. METHODS: To perform this analysis, we used samples from patients belonging to highly homogeneous population previously reported. Depletion of high abundant plasma proteins, 2D gel analysis, liquid chromatography-tandem mass spectrometry (LC-MS/MS) and bioinformatics analysis were used into an integrated approach to investigate tumor-specific changes in the plasma proteome of BC patients and healthy family members sharing the same BRCA1 gene founder mutation (5083del19), previously reported by our group, with the aim to identify specific signatures. RESULTS: The comparative analysis of the experimental results led to the identification of gelsolin as the most promising biomarker. CONCLUSIONS: Further analyses, performed using a panel of breast cancer cell lines, allowed us to further elucidate the signaling network that might modulate the expression of gelsolin in breast cancer.

Proteomics-driven analysis of ovine whey colostrum.

The aim of this study was to shed light in to the complexity of the ovine colostrum proteome, with a specific focus on the low abundance proteins. The ovine colostrum is characterized by a few dominating proteins, as the immunoglobulins, but it also contains less represented protein species, equally important for the correct development of neonates. Ovine colostrum, collected immediately after lambing, was separated by 1D SDS-PAGE. Proteins bands were digested with trypsin and the resulting peptides were analyzed by LC-MS/MS. On the basis of the Swiss-Prot database, a total of 343 unique proteins were identified. To our knowledge, this study represents the most comprehensive analysis of ovine colostrum proteome.