IL10 promoter variants are associated with gene expression but they are not markers of susceptibility to acute coronary syndrome.

Interleukin-10 (IL-10) is an immunomodulatory cytokine that plays a pivotal role in the pathogenesis of acute coronary syndromes (ACS). Here, we evaluated the role of IL10 promoter variants as markers for ACS susceptibility in Western Mexican patients as well as its association with IL10 mRNA and IL-10 plasma levels. Three promoter variants (- 1082 A > G, - 819 T > C and - 592 A > C) were analyzed in 300 ACS patients and 300 control group (CG) individuals. IL10 relative gene expression was evaluated in peripheral blood mononuclear cells (PBMC) and IL-10 levels were quantified in plasma. The allelic, genotypic and haplotypic frequencies did not show significant differences between groups. ACS patients had sevenfold higher mRNA IL10 level compared to CG (p = 0.0013). Homozygous C/C carriers in both - 819 T > C and - 592 A > C variants had 0.4-fold higher IL10 mRNA expression than heterozygous and polymorphic allele homozygous genotypes (p = 0.0357) in ACS group. There were significant differences in plasma IL-10 levels in CG and ACS group (1.001 vs 1.777 pg/mL, p = 0.0051). The variants were not markers of susceptibility to ACS in Western Mexican individuals. ACS patients showed higher IL10 expression than CG individuals which could be mediated by - 819 T > C and - 592 A > C variants and pharmacotherapy.

Relación de triglicéridos y estimación de riesgocardiovasculares en mujeres posmenopáusicas / Triglyceride ratio and cardiovascular risk estimation inpostmenopausal women

Objetivo: Determinar la relación de triglicéridos basales, con el riesgo a desarrollar enfermedades cardiovasculares en mujeres posmenopáusicas. Método: Estudio descriptivo, observacional y transversal, donde a 31 pacientes posmenopáusicas y sin antecedentes de enfermedades cardiometabólicas, se les determinó parámetros antropométricos (peso, talla, índice de masa corporal -IMC-); perfil lipídico en ayunas (colesterol total, triglicéridos o TG, lipoproteínas de baja y alta densidad -LDL, HDL-), por método enzimático colorimétrico, apolipoproteína B 100 (Apo B-100) por inmunodifusión radial, índices matemáticos LDL/Apo B-100y TG/HDL y cálculo de colesterol no-HDL. Resultados: los promedio y desviación de las variables fueron: edad:59±5 años con tiempo de posmenopausia: 8,77±3,92 años; IMC:27,6±4,4 kg/m.; colesterol total: 194±36 mg/dl; triglicéridos: 85±35 mg/dl; HDL: 33±8 mg/dl; LDL: 144±33 mg/dl; no-HDL: 159±37 mg/dl; Apo B-100: 172±246 mg/dl; LDL/Apo B-100: 1,15±0,03 y TG/HDL: 4,46±1,28. Discusión: Las pacientes se encontraron con sobrepeso, triglicéridos normales, colesterol total y LDL aumentado y las HDL bajas. El LDL-C/Apo B-100-100, que se relaciona con el tamaño y densidad de LDL, estuvo por debajo de 1,3 indicando la presencia de partículas pequeñas-densas, mientras TG/HDL, que se usa para estimar riesgo cardiovascular, estuvo por encima del corte establecido de 3,5. Conclusiones: Al relacionar los triglicéridos basales con LDL/Apo B-100 y TG/HDL, se observa que a partir del valor de triglicéridos de 100 mg/dl, se observa la presencia de partículas de lipoproteínas pequeñas-densas, y un alto riesgo cardiovascular, por lo que es necesario en mujeres posmenopáusicas el seguimiento a partir del valor de triglicéridos en 100 mg/dL ya que pudiera implicar el desarrollo de enfermedades cardiovasculares, en esta población(AU)

Objective: To determine the relationship of basal triglycerides with the risk of developing cardiovascular disease in postmenopausal women. Method: Descriptive, observational and cross-sectional study, where 31 postmenopause patients with no history of cardiometabolic disease were determined anthropometric parameters (weight, height, BMI); fasting lipid profile (total cholesterol, triglycerides or TG, LDL,HDL, by colorimetric enzymatic method), Apo B-100 (byradial immunodiffusion), LDL/Apo B-100 and TG/HDL mathematical indices and calculation of non-HDL cholesterol. Results: the mean and deviation of the variables were: age:59±5 years with postmenopause time: 8.77±3.92 years; BMI:27.6±4.4 kg/m2; total cholesterol: 194±36 mg/dl; triglycerides:85±35 mg/dl; HDL: 33±8 mg/dl; LDL: 144±33 mg/dl; non-HDL: 159±37 mg/dl; Apo B-100: 172±246 mg/dl; LDL/Apo B-100: 1.15±0.03 and TG/HDL: 4.46±1.28. Discussion: Patients were found to be overweight, normal triglycerides, total and LDL cholesterol high, and low HDL. LDL-C/ApoB-100-100, which is related to LDL size and density, was below 1.3 indicating the presence of small-dense particles, while TG/HDL, which is used to estimate cardiovascular risk, was above the established cut-off of 3.5. Conclusions: When relating the basal triglycerides with LDL/Apo B-100 and TG/HDL, it is observed that from the triglyceride value of 100mg/dl, the presence of small-dense lipoprotein particuals anda high cardiovascular risk is observed, so it is necessary in postmenopausal women to follow up from the triglycerid evalue in 100 mg/dL since it could imply the development of cardiovascular diseases, in this population(AU)

APOA1 (-75 G>A and 83 C>T) and APOB (2488 C>T) polymorphisms and their association with myocardial infarction, lipids and apolipoproteins in patients with type 2 diabetes mellitus.

Introduction: The increased risk of myocardial infarction (MI) in type 2 diabetes mellitus (T2DM) is well documented. Polymorphisms in APOA1 and APOB genes allow us to identify new genetic markers in the Mexican population with T2DM and MI. Material and methods: We studied 135 patients with DMT2 and MI (DI); another 85 non-infarcted diabetic individuals with DMT2 but without previous ischemic events (NID) and 242 healthy subjects (HS). All three groups were selected with the aim to investigate the association between the polymorphisms and infarction when T2DM is present or absent. Results: -75 G>A polymorphism: Differences were found in genotype distribution between DI and NID individuals (OR = 2.01, 95% CI: 1.117-3.623, p = 0.019) with an increased risk for A in the dominant model (OR = 1.77, 95% CI: 1.020-3.084, p = 0.042); also concentrations of ApoA-I for A/A were lower in comparison with G/A (p = 0.038) and LDL-C and HDL-C levels were lower in G/A compared to G/G carriers. 83 C>T polymorphism of APOA1: For DI individuals, HDL-C was lower in T/T compared to C/C and triglyceride levels were lower in C/T compared to C/C carriers. Conclusions: The -75 G>A APOA1 polymorphism could be considered as a susceptibility factor for myocardial infarction in individuals with T2DM and 2488 C>T APOB polymorphism is associated with changes in HDL-C and LDL-C and triglycerides in the same group.

Genetic variants, gene expression, and soluble CD36 analysis in acute coronary syndrome: Differential protein concentration between ST-segment elevation myocardial infarction and unstable angina.

BACKGROUND: Atherosclerosis plays an important role in the pathophysiology of acute coronary syndrome (ACS). CD36 is a scavenger receptor involved in lipid metabolism. Some single-nucleotide variants in the non-coding region could indirectly alter the expression and the function of the protein. OBJECTIVE: The aim of this study was to investigate the gene and protein expression associated with CD36 variants (rs1194182;C > G; rs1049654;C > A, rs1334512;G > T, and rs3211892;G > A) in ACS patients from the western Mexican population. METHODS: We recruited 310 ACS patients and 308 subjects in the control group (CG). Genotyping was determined by TaqMan SNP genotyping assays. CD36 expression at the mRNA level was quantified by TaqMan gene expression assays. Soluble CD36 (sCD36) was measured by enzyme-linked immunosorbent assay. RESULTS: We show that rs1194182G > C variant provides a protective effect with a 1.7-fold lower susceptibility to develop ACS (p  = 0.03); however, this association was masked by diabetes and dyslipidemia. We observed a higher sCD36 concentration in patient with ST-segment elevation myocardial infarction (STEMI) compared with patients with unstable angina (UA) (p  = 0.038). Likewise, in diabetic patients versus non-diabetic (p < 0.001). We observed in patients an increase in CD36 mRNA expression (1.91 times higher) than in the CG (p  = 0.02). CONCLUSION: The rs1194182 seems to be associated with diabetes in a risky manner, in ACS patients and protective for dyslipidemia in both groups. The concentration of sCD36 seems to be associated with the clinical spectrum of the ACS patients and the presence of diabetes, since patients with STEMI present significantly elevated level compared with UA.

Analysis of the APOB Gene and Apolipoprotein B Serum Levels in a Mexican Population with Acute Coronary Syndrome: Association with the Single Nucleotide Variants rs1469513, rs673548, rs676210, and rs1042034.

Apolipoprotein B (APOB) is associated with the development of atherosclerosis and consequently in the acute coronary syndrome (ACS) physiopathology. Single number variants (SNVs) in apolipoprotein B gene (APOB) influence over the susceptibility for this syndrome. The aim of this study was to determine the impact of the rs1469513, rs673548, rs676210, and rs1042034 SNVs and serum levels of APOB in the risk of ACS in a population from western Mexico. We included 300 patients in the group of cases (ACSG) and 300 individuals in the control group (CG). APOB levels were evaluated by immunonephelometry, and SNVs were genotyped with TaqMan probes. We found significant allelic and genotypic differences between groups for rs673548 and rs676210 (OR = 1.33, p=0.030, OR = 2.69, p < 0.001) and rs1042034 (OR = 0.50, p=0.037) SNVs. We found a risk haplotype TAGT (OR: 2.14, IC 1.50-3.04, p < 0.001). Our findings support a significant risk association between rs673548 and rs676210 variants for ACS; meanwhile, rs1042034 could be considered protective factor in a western Mexican population. Also, in this population, haplotype TAGT may confer 2.14 times a higher risk. APOB serum levels were compared by genotype variants in both groups without any significant statistical difference.

Virus-Mimic mRNA Vaccine for Cancer Treatment.

An effective therapeutic cancer vaccine should be empowered with the capacity to overcome the immunosuppressive tumor microenvironment. Here, the authors describe a mRNA virus-mimicking vaccine platform that is comprised of a phospholipid bilayer encapsulated with a protein-nucleotide core consisting of antigen-encoding mRNA molecules, unmethylated CpG oligonucleotides and positively charged proteins. In cell culture, VLVP potently stimulated bone marrow-derived dendritic cells (BMDCs) to express inflammatory cytokines that facilitated dendritic cell (DC) maturation and promoted antigen processing and presentation. In tumor-bearing mice, VLVP treatment stimulated proliferation of antigen-specific CD8+T cells in the lymphatic organs and T cell infiltration into the tumor bed, resulting in potent anti-tumor immunity. Cytometry by time of flight (CyTOF) analysis revealed that VLVP treatment stimulated a 5-fold increase in tumor-associated CD8+DCs and a 4-fold increase in tumorinfiltrated CD8+T cells, with concurrent decreases in tumor-associated bone marrow-derived suppressor cells and arginase 1- expressing suppressive DCs. Finally, CpG oligonucleotide is an essential adjuvant for vaccine activity. Inclusion of CpG not only maximized vaccine activity but also prevented PD-1 expression in T cells, serving the dual roles as a potent adjuvant and a checkpoint blockade agent.

Synergistic Activation of Antitumor Immunity by a Particulate Therapeutic Vaccine.

Success in anticancer immune therapy relies on stimulation of tumor antigen-specific T lymphocytes and effective infiltration of the T cells into tumor tissue. Here, a therapeutic vaccine that promotes proliferation and tumor infiltration of antigen-specific T cells in both inflamed and noninflamed tumor types is described. The vaccine consists of STING agonist 2'3'-cGAMP, TLR9 ligand CpG, and tumor antigen peptides that are loaded into nanoporous microparticles (µGCVax). µGCVax is effective in inhibiting lung metastatic melanoma, primary breast cancer, and subcutaneous colorectal cancer in their respective murine models, including functional cure of HER2-positive breast cancer. Mechanistically, µGCVax potently stimulates type I interferon expression in dendritic cells, and promotes CD8+ and CD103+ dendritic cell maturation and migration to lymph nodes and other lymphatic tissues. Antitumor responses are dependent on TLR9 and interferon α/ß receptor signaling, and to a less extent on STING signaling. These results demonstrate a high potential for µGCVax in mediating antitumor immunity in personalized cancer therapy.

Identification of an Aptamer With Binding Specificity to Tumor-Homing Myeloid-Derived Suppressor Cells.

Myeloid-derived suppressor cells (MDSCs) play a critical role in tumor growth and metastasis. Since they constantly infiltrate into the tumor tissue, these cells are considered as an ideal carrier for tumor-targeted drug delivery. We recently identified a DNA-based thioaptamer (T1) with tumor accumulating activity, demonstrated its potential on tumor targeting and drug delivery. In the current study, we have carried out structure-activity relationship analysis to further optimize the aptamer. In the process, we have identified a sequence-modified aptamer (M1) that shows an enhanced binding affinity to MDSCs over the parental T1 aptamer. In addition, M1 can penetrate into the tumor tissue more effectively by hitchhiking on MDSCs. Taken together, we have identified a new reagent for enhanced tumor-targeted drug delivery.

Application of exome sequencing to diagnose a novel presentation of the Cornelia de Lange syndrome in an Afro-Caribbean family.

BACKGROUND: Cornelia de Lange syndrome (CdLS) comprises a recognizable pattern of multiple congenital anomalies caused by variants of the DNA cohesion complex. Affected individuals may display a wide range of phenotypic severity, even within the same family. METHODS: Exome sequencing and confirmatory Sanger sequencing showed the same previously described p.Arg629Ter NIPBL variant in two half-brothers affected with CdLS. Clinical evaluations were obtained in a pro bono genetics clinic. RESULTS: One brother had relatively mild proportionate limb shortening; the other had complete bilateral hypogenesis of the upper arm with absence of lower arm structures, terminal transverse defects, and no digit remnants. His complex lower limb presentation included long bone deficiency and a deviated left foot. The mother had intellectual disability and microcephaly but lacked facial features diagnostic of the CdLS. CONCLUSION: We describe a collaboration between a pediatrics team from a resource-limited nation and USA-based medical geneticists. Reports describing individuals of West Indian ancestry are rarely found in the medical literature. Here, we present a family of Afro-Caribbean ancestry with CdLS presenting with phenotypic variability, including unusual lower limb abnormalities. The observation of this novel family adds to our knowledge of the phenotypic and molecular aspects of CdLS.

Analysis of Genetic Variation in CD40 and CD40L: Relationship with mRNA Relative Expression and Soluble Proteins in Acute Coronary Syndrome.

Acute coronary syndrome (ACS) can be triggered by the presence of inflammatory factors which promote the activation of immune cells by costimulatory molecules such as CD40 and its ligand CD40L. Environmental and genetic factors are involved in the etiology of the ACS. The aim of this study was to explore the gene and protein expression associated with CD40 and CD40L genetic variants in ACS patients from the western Mexican population. A total of 620 individuals from western Mexico were recruited: 320 ACS patients and 300 individuals without a history of ischemic cardiopathy were evaluated. The genotype was determined using TaqMan SNP genotyping assays. CD40 and CD40L expressions at the mRNA level were quantified using TaqMan Gene Expression Assays. Soluble protein isoforms were measured by enzyme-linked immunosorbent assay. We did not find evidence of association between CD40 (rs1883832, rs4810485, and rs11086998) and CD40L (rs3092952 and rs3092920) genetic variants and susceptibility to ACS, although rs1883832 and rs4810485 were significantly associated with high sCD40 plasma levels. Plasma levels of sCD40L can be affected by gender and the clinical spectrum of acute coronary syndrome. Our results do not suggest a functional role of CD40 and CD40L genetic variants in ACS. However, they could reflect the inflammatory process and platelet activation in ACS patients, even when they are under pharmacological therapy. Due to the important roles of the CD40-CD40L system in the pathogenesis of ACS, longitudinal studies are required to determine if soluble levels of CD40 and CD40L could be clinically useful markers of a recurrent cardiovascular event after an ACS.

Tracking Biodistribution of Myeloid-Derived Cells in Murine Models of Breast Cancer.

A growing tumor is constantly secreting inflammatory chemokines and cytokines that induce release of immature myeloid cells, including myeloid-derived suppressor cells (MDSCs) and macrophages, from the bone marrow. These cells not only promote tumor growth, but also prepare distant organs for tumor metastasis. On the other hand, the myeloid-derived cells also have phagocytic potential, and can serve as vehicles for drug delivery. We have previously identified thioaptamers that bind a subset of MDSCs with high affinity and specificity. In the current study, we applied one of the thioaptamers as a probe to track myeloid cell distribution in the bone, liver, spleen and tumor in multiple murine models of breast cancer including the 4T1 syngeneic model and MDA-MB-231 and SUM159 xenograft models. Information generated from this study will facilitate further understanding of tumor growth and metastasis, and predict biodistribution patterns of cell-mediated drug delivery.

Stabilization of the Max Homodimer with a Small Molecule Attenuates Myc-Driven Transcription.

The transcription factor Max is a basic-helix-loop-helix leucine zipper (bHLHLZ) protein that forms homodimers or interacts with other bHLHLZ proteins, including Myc and Mxd proteins. Among this dynamic network of interactions, the Myc/Max heterodimer has crucial roles in regulating normal cellular processes, but its transcriptional activity is deregulated in a majority of human cancers. Despite this significance, the arsenal of high-quality chemical probes to interrogate these proteins remains limited. We used small molecule microarrays to identify compounds that bind Max in a mechanistically unbiased manner. We discovered the asymmetric polycyclic lactam, KI-MS2-008, which stabilizes the Max homodimer while reducing Myc protein and Myc-regulated transcript levels. KI-MS2-008 also decreases viable cancer cell growth in a Myc-dependent manner and suppresses tumor growth in vivo. This approach demonstrates the feasibility of modulating Max with small molecules and supports altering Max dimerization as an alternative approach to targeting Myc.

Sensitizing non-small cell lung cancer to BCL-xL-targeted apoptosis.

Lung cancer is the leading cause of death in the United States, with non-small cell lung cancers (NSCLC) accounting for 85% of all cases. By analyzing the expression profile of the pro-apoptotic and anti-apoptotic proteins, we have assigned NSCLCs into two distinct groups. While single agent treatment with the BCL-2/BCL-xL/BCL-w inhibitor ABT-263 (navitoclax) did not trigger apoptosis in either group, cells with a moderate to high level of MCL-1 expression were sensitive to ABT-263 treatment when MCL-1 expression was suppressed with a gene-specific siRNA. In contrast, those with a low MCL-1 expression did not undergo apoptosis upon combination treatment with ABT-263 and MCL-1 siRNA. Further studies revealed that cells with a low MCL-1 expression had low mitochondrial priming, and treatment with the chemotherapy drug docetaxel raised the mitochondrial priming level and consequently sensitized cells to ABT-263. These results establish a rationale for molecular profiling and a therapeutic strategy to treat NSCLC patients with pro-apoptotic anti-cancer drugs based on their MCL-1 expression level.

Bone-targeting nanoparticle to co-deliver decitabine and arsenic trioxide for effective therapy of myelodysplastic syndrome with low systemic toxicity.

Myelodysplastic syndromes (MDS) are a diverse group of bone marrow disorders and clonal hematopoietic stem cell disorders characterized by abnormal blood cells, or reduced peripheral blood cell count. Recent clinical studies on combination therapy of decitabine (DAC) and arsenic trioxide (ATO) have demonstrated synergy on MDS treatment, but the treatment can cause significant side effects to patients. In addition, both drugs have to be administered on a daily basis due to their short half-lives. In addressing key issues of reducing toxic side effects and improving pharmacokinetic profiles of the therapeutic agents, we have developed a new formulation by co-packaging DAC and ATO into alendronate-conjugated bone-targeting nanoparticles (BTNPs). Our pharmacokinetic studies revealed that intravenously administered BTNPs increased circulation time up to 3days. Biodistribution analysis showed that the BTNP facilitated DAC and ATO accumulation in the bone, which is 6.7 and 7.9 times more than untargeted NP. Finally, MDS mouse model treated with BTNPs showed better restoration of complete blood count to normal level, and significantly longer median survival as compared to free drugs or untargeted NPs treatment. Our results support bone-targeted co-delivery of DAC and ATO for effective treatment of MDS.

Methotraxate-Loaded Hybrid Nanoconstructs Target Vascular Lesions and Inhibit Atherosclerosis Progression in ApoE-/- Mice.

Atherosclerosis is an inflammatory disorder characterized by the progressive thickening of blood vessel walls eventually resulting in acute vascular syndromes. Here, intravenously injectable hybrid nanoconstructs are synthesized for tempering immune cell inflammation locally and systemically. Lipid and polymer chains are nanoprecipitated to form 100 nm spherical polymeric nanoconstructs (SPNs), loaded with methotrexate (MTX) and subsequently labeled with Cu64 and fluorescent probes for combined nuclear/optical imaging. Upon engulfment into macrophages, MTX SPNs intracellularly release their anti-inflammatory cargo significantly lowering the production of proinflammatory cytokine (interleukin 6 and tumor necrosis factor α) already at 0.06 mg mL-1 of MTX. In ApoE-/- mice, fed with high-fat diet up to 17 weeks, nuclear and optical imaging demonstrates specific accumulation of SPNs within lipid-rich plaques along the arterial tree. Histological analyses confirm SPN uptake into macrophages residing within atherosclerotic plaques. A 4-week treatment with biweekly administration of MTX SPNs is sufficient to reduce the plaque burden in ApoE-/- mice by 50%, kept on high-fat diet for 10 weeks. Systemic delivery of MTX to macrophages via multifunctional, hybrid nanoconstructs constitutes an effective strategy to inhibit atherosclerosis progression and induce, potentially, the resorption of vascular lesions.

Assembly of Iron Oxide Nanocubes for Enhanced Cancer Hyperthermia and Magnetic Resonance Imaging.

Multiple formulations of iron oxide nanoparticles (IONPs) have been proposed for enhancing contrast in magnetic resonance imaging (MRI) and for increasing efficacy in thermal ablation therapies. However, insufficient accumulation at the disease site and low magnetic performance hamper the clinical application of IONPs. Here, 20 nm iron oxide nanocubes were assembled into larger nanoconstructs externally stabilized by a serum albumin coating. The resulting assemblies of nanocubes (ANCs) had an average diameter of 100 nm and exhibited transverse relaxivity (r2 = 678.9 ± 29.0 mM‒1·s‒1 at 1.41 T) and heating efficiency (specific absorption rate of 109.8 ± 12.8 W·g‒1 at 512 kHz and 10 kA·m‒1). In mice bearing glioblastoma multiforme tumors, Cy5.5-labeled ANCs allowed visualization of malignant masses via both near infrared fluorescent and magnetic resonance imaging. Also, upon systemic administration of ANCs (5 mgFe·kg‒1), 30 min of daily exposure to alternating magnetic fields for three consecutive days was sufficient to halt tumor progression. This study demonstrates that intravascular administration of ANCs can effectively visualize and treat neoplastic masses.

Paramagnetic Gd(3+) labeled red blood cells for magnetic resonance angiography.

Despite significant advances in contrast enhanced-magnetic resonance angiography, the lack of truly blood-pool agents with long circulating property is limiting the clinical impact of this imaging technique. The terminal half-life for blood elimination of most small molecular weight gadolinium (Gd) based extracellular fluid agents is about 1.5 h when administered intravenously to subjects with normal renal function. The small size of these extracellular fluid agents does not prevent them from extravasating, especially from damaged vessels which are generally hyperpermeable. Therefore, the development of novel, clinically relevant blood pool contrast agents is critically needed to improve outcomes in the prevention, detection, and treatment of vascular diseases. We have demonstrated the fusion strategies in which the Gd-liposome without any stealth property radically fuses with red blood cells (RBCs) forming MR glowing Gd-RBC with the order of magnitude enhancements in circulation half-life (t1/2 = 50 h) and r1 relaxivity (r1 = 19.0 mM(-1) s(-1)) of Gd. The in vivo contrast enhancement of Gd-RBC was studied by using 3T clinical MR scanner for extended period of time, which clearly visualized the abdominal aorta. In summary, the vascular delivery of blood pool agents may benefit from carriage by RBCs because it naturally stays within the vascular lumen.

Geometrical confinement of Gd(DOTA) molecules within mesoporous silicon nanoconstructs for MR imaging of cancer.

Porous silicon has been used for the delivery of therapeutic and imaging agents in several biomedical applications. Here, mesoporous silicon nanoconstructs (SiMPs) with a discoidal shape and a sub-micrometer size (1000×400nm) have been conjugated with gadolinium-tetraazacyclododecane tetraacetic acid Gd(DOTA) molecules and proposed as contrast agents for Magnetic Resonance Imaging. The surface of the SiMPs with different porosities - small pore (SP: ∼5nm) and huge pore (HP: ∼40nm) - and of bulk, non-porous silica beads (1000nm in diameter) have been modified with covalently attached (3-aminopropyl)triethoxysilane (APTES) groups, conjugated with DOTA molecules, and reacted with an aqueous solution of GdCl3. The resulting Gd(DOTA) molecules confined within the small pores of the Gd-SiMPs achieve longitudinal relaxivities r1 of ∼17 (mMs)(-)(1), which is 4 times greater than for free Gd(DOTA). This enhancement is ascribed to the confinement and stable chelation of Gd(DOTA) molecules within the SiMP mesoporous matrix. The resulting nanoconstructs possess no cytotoxicity and accumulate in ovarian tumors up to 2% of the injected dose per gram tissue, upon tail vein injection. All together this data suggests that Gd-SiMPs could be efficiently used for MR vascular imaging in cancer and other diseases.

"Triplet" polycistronic vectors encoding Gata4, Mef2c, and Tbx5 enhances postinfarct ventricular functional improvement compared with singlet vectors.

OBJECTIVE: The in situ reprogramming of cardiac fibroblasts into induced cardiomyocytes by the administration of gene transfer vectors encoding Gata4 (G), Mef2c (M), and Tbx5 (T) has been shown to improve ventricular function in myocardial infarction models. The efficacy of this strategy could, however, be limited by the need for fibroblast targets to be infected 3 times--once by each of the 3 transgene vectors. We hypothesized that a polycistronic "triplet" vector encoding all 3 transgenes would enhance postinfarct ventricular function compared with use of "singlet" vectors. METHODS: After validation of the polycistronic vector expression in vitro, adult male Fischer 344 rats (n=6) underwent coronary ligation with or without intramyocardial administration of an adenovirus encoding all 3 major vascular endothelial growth factor (VEGF) isoforms (AdVEGF-All6A positive), followed 3 weeks later by the administration to AdVEGF-All6A-positive treated rats of singlet lentivirus encoding G, M, or T (1×10(5) transducing units each) or the same total dose of a GMT "triplet" lentivirus vector. RESULTS: Western blots demonstrated that triplet and singlet vectors yielded equivalent GMT transgene expression, and fluorescence activated cell sorting demonstrated that triplet vectors were nearly twice as potent as singlet vectors in generating induced cardiomyocytes from cardiac fibroblasts. Echocardiography demonstrated that GMT triplet vectors were more effective than the 3 combined singlet vectors in enhancing ventricular function from postinfarct baselines (triplet, 37%±10%; singlet, 13%±7%; negative control, 9%±5%; P<.05). CONCLUSIONS: These data have confirmed that the in situ administration of G, M, and T induces postinfarct ventricular functional improvement and that GMT polycistronic vectors enhance the efficacy of this strategy.

microRNA-22 promotes heart failure through coordinate suppression of PPAR/ERR-nuclear hormone receptor transcription.

Increasing evidence suggests that microRNAs are intimately involved in the pathophysiology of heart failure. MicroRNA-22 (miR-22) is a muscle-enriched miRNA required for optimum cardiac gene transcription and adaptation to hemodynamic stress by pressure overload in mice. Recent evidence also suggests that miR-22 induces hypertrophic growth and it is oftentimes upregulated in end stage heart failure. However the scope of mRNA targets and networks of miR-22 in the heart failure remained unclear. We analyzed transgenic mice with enhanced levels of miR-22 expression in adult cardiomyocytes to identify important pathophysiologic targets of miR-22. Our data shows that forced expression of miR-22 induces a pro-hypertrophic gene expression program, and it elicits contractile dysfunction leading to cardiac dilation and heart failure. Increased expression of miR-22 impairs the Ca(2+) transient, Ca(2+) loading into the sarcoplasmic reticulum plus it interferes with transcription of estrogen related receptor (ERR) and PPAR downstream genes. Mechanistically, miR-22 postranscriptionally inhibits peroxisome proliferator-activated receptor gamma coactivator 1 alpha (PGC-1α), PPARα and sirtuin 1 (SIRT1) expression via a synergistic circuit, which may account for deleterious actions of unchecked miR-22 expression on the heart.