Biology subjects

Marban, E.

Publications and source records attributed to Marban, E..

6 recordsLinked to original sources

bioRxiv2025

Multicenter HFpEF study identifies sex disparity linked with two discrete cardiac proteomic signatures

Heart failure with preserved ejection fraction (HFpEF) is epidemic, with an incidence exceeding that of heart failure with reduced ejection fraction (HFrEF). Sex differences in HFpEF phenotype have been observed, particularly linked to aging and metabolic comorbidities in women. Here, we report a multi-centre proteomic analysis of HFpEF and HFrEF cardiac samples. Using tissues and clinical data derived from multiple institutional biobanks, in-depth characterization of the proteome of ventricular samples was undertaken. Relative to HFrEF, the HFpEF cohort exhibited minimal proteome composition overlap and pronounced heterogeneity. A key finding of this investigation is that sex per se did not confer a distinctive proteomic HFpEF signature. Rather, two HFpEF proteomic profiles were identified, differing significantly in sex ratios. The identification of two Clusters revealed that HFpEF has two predominant proteomic signatures at the molecular level, marked by differences in the extent and nature of structural and contractile machinery and by local cellular and ECM communications. Upstream regulator analysis identified various molecular leads to be pursued in defining these two HFpEF profiles. Our findings offer specific opportunities for new exploration of therapeutic options to target the spectrum of HFpEF proteomic diversity and identify potential drug targeting prospects.

molecular biology↗

bioRxiv2024

Oral bioavailability of a noncoding RNA drug, TY1, that acts on macrophages

All approved RNA therapeutics require parenteral delivery. Here we demonstrate an orally bioavailable formulation wherein synthetic noncoding (nc) RNA, packaged into lipid nanoparticles, is loaded into casein-chitosan (C2) micelles. We used the C2 formulation to deliver TY1, a 24-nucleotide synthetic ncRNA which targets the DNA damage response pathway in macrophages. C2-formulated TY1 (TY1C2) efficiently packages and protects TY1 against degradative enzymes. In healthy mice, oral TY1C2 was well-tolerated and nontoxic. Oral TY1C2 exhibited disease-modifying bioactivity in 2 models of tissue injury: 1) rat myocardial infarction, where a single oral dose of TY1C2 was cardioprotective, on par with intravenously-delivered TY1; and 2) mouse acute lung injury, where a single dose of TY1C2 attenuated pulmonary inflammation. Mechanistic dissection revealed that TY1C2 is not absorbed into the systemic circulation but is, instead, taken up by intestinal macrophages, namely those of the lamina propria and Peyers patches. This route of absorption may rationalize why an antisense oligonucleotide against Factor VII, which acts on hepatocytes, is not effective when administered in the C2 formulation. Thus, some (but not all) ncRNA drugs are bioavailable when delivered by mouth. Oral RNA delivery and uptake, relying on uptake via the gastrointestinal immune system, has broad-ranging therapeutic implications. Graphical AbstractOral TY1C2 is taken up in the small intestine mainly by macrophages of the lamina propria and the Peyers patches. Macrophages that have taken up oral TY1C2 mediate disease-modifying bioactivity in 2 animal models of acute tissue injury. The blue + denotes the as-yet-uncertain mechanisms/mediators linking TY1 gut uptake to the drugs systemic therapeutic benefits. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=74 SRC="FIGDIR/small/591474v1_ufig1.gif" ALT="Figure 1"> View larger version (21K): org.highwire.dtl.DTLVardef@8bfffdorg.highwire.dtl.DTLVardef@15379e5org.highwire.dtl.DTLVardef@167e9aaorg.highwire.dtl.DTLVardef@11dd317_HPS_FORMAT_FIGEXP M_FIG C_FIG

synthetic biology↗

bioRxiv2024

Augmentation of DNA exonuclease TREX1 in macrophages as a therapy for cardiac ischemic injury

Noncoding RNAs (ncRNAs) are increasingly recognized as bioactive. Here we report the development of TY1, a synthetic ncRNA bioinspired by a naturally-occurring human small Y RNA with immunomodulatory properties. TY1 upregulates TREX1, an exonuclease that rapidly degrades cytosolic DNA. In preclinical models of myocardial infarction (MI) induced by ischemia/reperfusion, TY1 reduced scar size. The cardioprotective effect of TY1 was abrogated by prior depletion of macrophages and mimicked by adoptive transfer of macrophages exposed either to TY1 or TREX1. Inhibition of TREX1 in macrophages blocked TY1 cardioprotection. Consistent with a central role for TREX1, TY1 attenuated DNA damage in the post-MI heart. This novel mechanism--pharmacologic upregulation of TREX1 in macrophages--establishes TY1 as the prototype for a new class of ncRNA drugs with disease-modifying bioactivity. One Sentence SummaryUpregulation of three prime exonuclease, TREX1, in macrophages enhances tissue repair post myocardial infarction.

molecular biology↗

bioRxiv2023

High Throughput Proteomic Analysis of Heterogeneous Cell Populations with NanoDTSC

Identification and proteomic characterization of rare cell types within complex organ derived cell mixtures is best accomplished by label-free quantitative mass spectrometry. High throughput is required to rapidly survey hundreds to thousands of individual cells to adequately represent rare populations. Here we present parallelized nanoflow dual-trap single-column liquid chromatography (nanoDTSC) operating at 15 minutes of total run time per cell with peptides quantified over 11.5 minutes using standard commercial components, thus offering an accessible and efficient LC solution to analyze 96 single-cells per day. At this throughput, nanoDTSC quantified over 1,000 proteins in individual cardiomyocytes and heterogenous populations of single cells from aorta. For Table of Contents Only O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=113 SRC="FIGDIR/small/522908v4_ufig1.gif" ALT="Figure 1"> View larger version (33K): org.highwire.dtl.DTLVardef@352d49org.highwire.dtl.DTLVardef@1304d2corg.highwire.dtl.DTLVardef@1a9df5org.highwire.dtl.DTLVardef@1785464_HPS_FORMAT_FIGEXP M_FIG C_FIG

biochemistry↗

bioRxiv2021

Mechanistic dissection of global proteomic changes in rats with heart failure and preserved ejection fraction

IntroductionHeart failure with preserved ejection fraction (HFpEF) is characterized by diastolic dysfunction, pulmonary congestion and exercise intolerance. Previous preclinical studies show that treatment with cardiosphere-derived cells (CDCs) improves diastolic function, attenuates arrhythmias and prolongs survival in a rat HFpEF model. Here we characterize the myocardial proteome and diastolic function in HFpEF, with and without CDC therapy. As an initial strategy for identifying pathways worthy of further mechanistic dissection, we correlated CDC-responsive proteomic changes with functional improvements. Methods and ResultsDahl salt-sensitive rats fed high-salt diet, with verified diastolic dysfunction, were randomly assigned to intracoronary CDCs or placebo. Dahl rats fed a low salt diet served as controls. Phenotyping was by echocardiography (E/A ratio) and invasive hemodynamic monitoring (time constant of relaxation Tau, and left ventricular end-diastolic pressure [LVEDP]). CDC treatment improved diastolic function as indicated by a normalized E/A ratio, a 33.3% reduction in Tau, and a 47% reduction of LVEDP. Mass spectrometry of left ventricular tissues (n=6/group) revealed changes in transcription and translation pathways in this rat HFpEF model and was also recapitulated in human HFpEF. These pathways were enhanced following CDC treatment in the animal model (205 proteins and 32 phosphorylated residues accounting for 37% and 19% of all changes, respectively). Among all CDC-sensitive pathways, 65% can be linked to at least 1 of 7 upstream regulators, among which several are of potential relevance for regulating protein expression. To probe newly-synthesized proteins AHA labeling was carried out in isolated rat cardiomyocytes obtained from HFpEF groups, with and without CDC therapy. Five of the initial upstream regulators (HNF4A, MTOR, MYC, TGF{beta}1, and TP53) were linked to proteins expressed exclusively (or increased) with CDC treatment. All 32 phosphorylated residues of proteins involved in transcription/translation altered specifically by CDC treatment had predicted kinases (Protein kinase C (PKC) being the most dominant) and known to be regulated by MYC, TGF{beta}1 and/or TP53. Western blot analysis of those 5 upstream regulators showed that TGF{beta}1, TP53, and Myc were significantly decreased in LV from CDC treated animals, whereas MTOR and HNF4A showed a significant increase compared to HFpEF alone. The cellular quantities of several upstream regulator correlated with indices of diastolic function (E/A ratio, Tau and/or LVEDP). Since CDCs act via the secretion of exosomes laden with signaling cargo, it is relevant that all 7 upstream regulators could, in principle, be regulated by proteins or miRNA that are present in CDC-derived exosomes. ConclusionWe identified key cellular regulators of transcription and translation that underlie the therapeutic effects of CDCs in HFpEF, whose levels correlate quantitatively with measures of diastolic function. Among the multifarious proteomic changes associated with rat model of HFpEF which were also observed in human HFpEF samples, we propose that these regulators, and downstream effector kinases, be prioritized for further dedicated mechanistic dissection.

molecular biology↗

bioRxiv2017

Reversal of cardiac and skeletal manifestations of Duchenne muscular dystrophy by cardiosphere-derived cells and their exosomes in mdx dystrophic mice and in human Duchenne cardiomyocytes

Genetic deficiency of dystrophin leads to disability and premature death in Duchenne muscular dystrophy, affecting the heart as well as skeletal muscle. Here we report that cardiosphere-derived cells (CDCs), which are being tested clinically for the treatment of Duchenne cardiomyopathy, improve cardiac and skeletal myopathy in the mdx mouse model of DMD and in human Duchenne cardiomyocytes. Injection of CDCs into the hearts of mdx mice augments cardiac function, ambulatory capacity and survival. Exosomes secreted by human CDCs reproduce the benefits of CDCs in mdx mice and in human Duchenne cardiomyocytes. The findings further motivate the testing of CDCs in Duchenne patients, while identifying exosomes as next-generation therapeutic candidates.

physiology↗