Latent disease similarities and therapeutic repurposing possibilities uncovered by multi-modal generative topic modeling of human diseases.

Motivation: Human diseases are characterized by multiple features such as their pathophysiological, molecular and genetic changes. The rapid expansion of such multi-modal disease-omics space provides an opportunity to re-classify diverse human diseases and to uncover their latent molecular similarities, which could be exploited to repurpose a therapeutic-target for one disease to another. Results: Herein, we probe this underexplored space by soft-clustering 6955 human diseases by multi-modal generative topic modeling. Focusing on chronic kidney disease and myocardial infarction, two most life-threatening diseases, unveiled are their previously underrecognized molecular similarities to neoplasia and mental/neurological-disorders, and 69 repurposable therapeutic-targets for these diseases. Using an edit-distance-based pathway-classifier, we also find molecular pathways by which these targets could elicit their clinical effects. Importantly, for the 17 targets, the evidence for their therapeutic usefulness is retrospectively found in the pre-clinical and clinical space, illustrating the effectiveness of the method, and suggesting its broader applications across diverse human diseases. Availability and implementation: The code reported in this article is available at: https://github.com/skozawa170301ktx/MultiModalDiseaseModeling. Supplementary information: Supplementary data are available at Bioinformatics Advances online.

Pressure Overload-Mediated Sustained PKR2 (Prokineticin-2 Receptor) Signaling in Cardiomyocytes Contributes to Cardiac Hypertrophy and Endotheliopathies.

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The Body-wide Transcriptome Landscape of Disease Models.

Virtually all diseases affect multiple organs. However, our knowledge of the body-wide effects remains limited. Here, we report the body-wide transcriptome landscape across 13-23 organs of mouse models of myocardial infarction, diabetes, kidney diseases, cancer, and pre-mature aging. Using such datasets, we find (1) differential gene expression in diverse organs across all models; (2) skin as a disease-sensor organ represented by disease-specific activities of putative gene-expression network; (3) a bone-skin cross talk mediated by a bone-derived hormone, FGF23, in response to dysregulated phosphate homeostasis, a known risk-factor for kidney diseases; (4) candidates for the signature activities of many more putative inter-organ cross talk for diseases; and (5) a cross-species map illustrating organ-to-organ and model-to-disease relationships between human and mouse. These findings demonstrate the usefulness and the potential of such body-wide datasets encompassing mouse models of diverse disease types as a resource in biological and medical sciences. Furthermore, the findings described herein could be exploited for designing disease diagnosis and treatment.

Discovery and cardioprotective effects of the first non-Peptide agonists of the G protein-coupled prokineticin receptor-1.

Prokineticins are angiogenic hormones that activate two G protein-coupled receptors: PKR1 and PKR2. PKR1 has emerged as a critical mediator of cardiovascular homeostasis and cardioprotection. Identification of non-peptide PKR1 agonists that contribute to myocardial repair and collateral vessel growth hold promises for treatment of heart diseases. Through a combination of in silico studies, medicinal chemistry, and pharmacological profiling approaches, we designed, synthesized, and characterized the first PKR1 agonists, demonstrating their cardioprotective activity against myocardial infarction (MI) in mice. Based on high throughput docking protocol, 250,000 compounds were computationally screened for putative PKR1 agonistic activity, using a homology model, and 10 virtual hits were pharmacologically evaluated. One hit internalizes PKR1, increases calcium release and activates ERK and Akt kinases. Among the 30 derivatives of the hit compound, the most potent derivative, IS20, was confirmed for its selectivity and specificity through genetic gain- and loss-of-function of PKR1. Importantly, IS20 prevented cardiac lesion formation and improved cardiac function after MI in mice, promoting proliferation of cardiac progenitor cells and neovasculogenesis. The preclinical investigation of the first PKR1 agonists provides a novel approach to promote cardiac neovasculogenesis after MI.

An anthelmintic drug, pyrvinium pamoate, thwarts fibrosis and ameliorates myocardial contractile dysfunction in a mouse model of myocardial infarction.

Metabolic adaptation to limited supplies of oxygen and nutrients plays a pivotal role in health and disease. Heart attack results from insufficient delivery of oxygen and nutrients to the heart, where cardiomyocytes die and cardiac fibroblasts proliferate--the latter causing scar formation, which impedes regeneration and impairs contractility of the heart. We postulated that cardiac fibroblasts survive metabolic stress by adapting their intracellular metabolism to low oxygen and nutrients, and impeding this metabolic adaptation would thwart their survival and facilitate the repair of scarred heart. Herein, we show that an anthelmintic drug, Pyrvinium pamoate, which has been previously shown to compromise cancer cell survival under glucose starvation condition, also disables cardiac fibroblast survival specifically under glucose deficient condition. Furthermore, Pyrvinium pamoate reduces scar formation and improves cardiac contractility in a mouse model of myocardial infarction. As Pyrvinium pamoate is an FDA-approved drug, our results suggest a therapeutic use of this or other related drugs to repair scarred heart and possibly other organs.

Prokineticin receptor-1 is a new regulator of endothelial insulin uptake and capillary formation to control insulin sensitivity and cardiovascular and kidney functions.

BACKGROUND: Reciprocal relationships between endothelial dysfunction and insulin resistance result in a vicious cycle of cardiovascular, renal, and metabolic disorders. The mechanisms underlying these impairments are unclear. The peptide hormones prokineticins exert their angiogenic function via prokineticin receptor-1 (PKR1). We explored the extent to which endothelial PKR1 contributes to expansion of capillary network and the transcapillary passage of insulin into the heart, kidney, and adipose tissues, regulating organ functions and metabolism in a specific mice model. METHODS AND RESULTS: By combining cellular studies and studies in endothelium-specific loss-of-function mouse model (ec-PKR1-/-), we showed that a genetically induced PKR1 loss in the endothelial cells causes the impaired capillary formation and transendothelial insulin delivery, leading to insulin resistance and cardiovascular and renal disorders. Impaired insulin delivery in endothelial cells accompanied with defective expression and activation of endothelial nitric oxide synthase in the ec-PKR1-/- aorta, consequently diminishing endothelium-dependent relaxation. Despite having a lean body phenotype, ec-PKR1-/- mice exhibited polyphagia, polydipsia, polyurinemia, and hyperinsulinemia, which are reminiscent of human lipodystrophy. High plasma free fatty acid levels and low leptin levels further contribute to the development of insulin resistance at the later age. Peripheral insulin resistance and ectopic lipid accumulation in mutant skeletal muscle, heart, and kidneys were accompanied by impaired insulin-mediated Akt signaling in these organs. The ec-PKR1-/- mice displayed myocardial fibrosis, low levels of capillary formation, and high rates of apoptosis, leading to diastolic dysfunction. Compact fibrotic glomeruli and high levels of phosphate excretion were found in mutant kidneys. PKR1 restoration in ec-PKR1-/- mice reversed the decrease in capillary recruitment and insulin uptake and improved heart and kidney function and insulin resistance. CONCLUSIONS: We show a novel role for endothelial PKR1 signaling in cardiac, renal, and metabolic functions by regulating transendothelial insulin uptake and endothelial cell proliferation. Targeting endothelial PKR1 may serve as a therapeutic strategy for ameliorating these disorders.

Prokineticin receptor 1 (PKR1) signalling in cardiovascular and kidney functions.

Prokineticins (PK1 and PK2) are peptide hormones that exert their biological activity via two common G-protein-coupled receptors: prokineticin receptor (PKR) 1 and 2. Their physiology was originally explored mostly in the context of angiogenic actions in the reproductive tract and gut motility. Since autocrine and paracrine loops have been established between PK2 and PKR1 in the heart, in this review we focus on the PK2/PKR1 signalling in the functions of the heart and kidney. PKR1 signalling is required for cardiomyocyte survival and angiogenesis. In the mouse model of myocardial infarction, intracardiac transient PKR1 transfection protects the structure and function of the heart. Gain- and loss-of-function studies reveal that PKR1 in mouse heart up-regulates its own ligand and PK2, which in turn acts as a paracrine signal and promotes epicardin-positive progenitor cell differentiation into a vasculogenic cell type. Transgenic mice over-expressing PKR1 in cardiomyocytes exhibit increased neovascularization. Loss of PKR1 causes structural and functional changes in the heart and kidney. In isolated epicardin-positive progenitor cells from the kidney, PK2, acting via PKR1, stimulates differentiation of these progenitor cells into endothelial and smooth muscle cells. Taken together, these data show that PK2/PKR1 is involved in postnatal cardiac and renal neovascularization. The knowledge gained from these studies should facilitate the discovery of therapeutic interventions in heart and kidney diseases targeting PKR1.

Genetic inactivation of prokineticin receptor-1 leads to heart and kidney disorders.

OBJECTIVE: Prokineticins are potent angiogenic hormones that use 2 receptors, prokineticin receptor-1 (PKR1) and PKR2, with important therapeutic use in anticancer therapy. Observations of cardiac and renal toxicity in cancer patients treated with antiangiogenic compounds led us to explore how PKR1 signaling functioned in heart and kidney in vivo. METHODS AND RESULTS: We generated mice with a conditional disruption of the PKR1 gene. We observed that PKR1 loss led to cardiomegaly, severe interstitial fibrosis, and cardiac dysfunction under stress conditions, accompanied by renal tubular dilation, reduced glomerular capillaries, urinary phosphate excretion, and proteinuria at later ages. Abnormal mitochondria and increased apoptosis were evident in both organs. Perturbation of capillary angiogenesis in both organs was restored at the adult stage potentially via upregulation of hypoxia-inducible factor-1 and proangiogenic factors. Compensatory mechanism could not revoke the epicardial and glomerular capillary networks, because of increased apoptosis and reduced progenitor cell numbers, consistent with an endogenous role of PKR1 signaling in stimulating epicardin+ progenitor cell proliferation and differentiation. CONCLUSIONS: Here, we showed for the first time that the loss of PKR1 causes renal and cardiac structural and functional changes because of deficits in survival signaling, mitochondrial, and progenitor cell functions in found both organs.

Divergent roles of prokineticin receptors in the endothelial cells: angiogenesis and fenestration.

Prokineticins are secreted peptides that activate two G protein-coupled receptors: PKR1 and PKR2. Prokineticins induce angiogenesis and fenestration, but the cognate receptors involved in these functions are unknown. We hypothesized a role for prokineticin receptor signaling pathways and expression profiles in determining the selective effects of prokineticins on coronary endothelial cells (H5V). Activation of the PKR1/MAPK/Akt signaling pathway stimulates proliferation, migration, and angiogenesis in H5V cells, in which PKR1 predominates over PKR2. PKR1 was colocalized with Galpha(11) and was internalized following the stimulation of these cells with prokineticin-2. Knock down of PKR1 or Galpha(11) expression in H5V cells effectively inhibited prokineticin-2-induced vessel formation and MAPK/Akt activation, indicating a role for PKR1/Galpha(11) in this process. However, in conditions in which PKR2 predominated over PKR1, these cells displayed a fenestrated endothelial cell phenotype. H5V cells overexpressing PKR2 displayed large numbers of multivesicular bodies and caveolar clusters and a disruption of the distribution of zonula occluden-1 tight junction protein. Prokineticin-2 induced the colocalization of PKR2 with Galpha(12), and activated Galpha(12), which bound to zonula occluden-1 to trigger the degradation of this protein in these cells. Prokineticin-2 induced the formation of vessel-like structures by human aortic endothelial cells expressing only PKR1, and disorganized the tight junctions in human hepatic sinusoidal endothelial cells expressing only PKR2, confirming the divergent roles of these receptors. Our findings show the functional characteristics of coronary endothelial cells depend on the expression of PKR1 and PKR2 levels and the divergent signaling pathways used by these receptors.

Transgenic myocardial overexpression of prokineticin receptor-2 (GPR73b) induces hypertrophy and capillary vessel leakage.

AIMS: Prokineticins are small secreted bioactive molecules. They exert their biological activity by binding to two G protein-coupled receptors. Previously, we have shown that the overexpression of prokineticin receptor-1 (PKR1) in transgenic (TG) mouse hearts induced neovascularization. Since PKR1 and PKR2 are 85% identical and expressed in cardiovascular tissues, we hypothesized that PKR2 may also contribute to cardiomyocyte growth and vascularization. METHODS AND RESULTS: We have generated TG mice overexpressing PKR2 in cardiomyocytes. TG mice exhibit increased hypertrophic gene expression and heart-to-body weight ratio accompanied by an increased length of cardiomyocytes at the age of 12 weeks. Increased left ventricular end-systolic and diastolic diameters without cardiac dysfunction at the age of 24 weeks indicate that TG mice have an eccentric hypertrophy with compensated cardiac function. Quantitative morphological analysis showed that TG hearts have a normal microvessel density and number of branch points. However, they exhibit increased abnormal endothelial cell shape and ultrastructure, changed cellular distribution of a tight junction protein zona occludens-1 (ZO-1), and vascular leakage in heart without a rise of angiogenic factor levels at early and late age. The application of media conditioned by H9c2 cardioblast cells overexpressing PKR2 significantly induced impaired ZO-1 localization in H5V endothelial cells, mimicking the TG model. CONCLUSION: These findings provide the first genetic evidence that cardiomyocyte PKR2 signalling leads to eccentric hypertrophy in an autocrine regulation and impaired endothelial integrity in a paracrine regulation without inducing angiogenesis. These TG mice may provide a new genetic model for heart diseases.

Prokineticin receptor-1 induces neovascularization and epicardial-derived progenitor cell differentiation.

OBJECTIVE: Identification of novel factors that contribute to myocardial repair and collateral vessel growth hold promise for treatment of heart diseases. We have shown that transient prokineticin receptor-1 (PKR1) gene transfer protects the heart against myocardial infarction in a mouse model. Here, we investigated the role of excessive PKR1 signaling in heart. METHODS AND RESULTS: Transgenic mice overexpressing PKR1 in cardiomyocytes displayed no spontaneous abnormalities in cardiomyocytes but showed an increased number of epicardial-derived progenitor cells (EPDCs), capillary density, and coronary arterioles. Coculturing EPDCs with H9c2 cardiomyoblasts overexpressing PKR1 promotes EPDC differentiation into endothelial and smooth muscle cells, mimicking our transgenic model. Overexpressing PKR1 in H9c2 cardiomyoblasts or in transgenic hearts upregulated prokineticin-2 levels. Exogenous prokineticin-2 induces significant outgrowth from neonatal and adult epicardial explants, promoting EPDC differentiation. These prokineticin-2 effects were abolished in cardiac explants from mice with PKR1-null mutation. Reduced capillary density and prokineticin-2 levels in PKR1-null mutant hearts supports the hypothesis of an autocrine/paracrine loop between PKR1 and prokineticin-2. CONCLUSIONS: Cardiomyocyte-PKR1 signaling upregulates its own ligand prokineticin-2 that acts as a paracrine factor, triggering EPDCs proliferation/differentiation. This study provides a novel insight for possible therapeutic strategies aiming at restoring pluripotency of adult EPDCs to promote neovasculogenesis by induction of cardiomyocyte PKR1 signaling.

The prokineticin receptor-1 (GPR73) promotes cardiomyocyte survival and angiogenesis.

Prokineticins are potent angiogenic factors that bind to two G protein-coupled receptors to initiate their biological effects. We hypothesize that prokineticin receptor-1 (PKR1/GPR73) signaling may contribute to cardiomyocyte survival or repair in myocardial infarction. Since we showed that prokineticin-2 and PKR1 are expressed in adult mouse heart and cardiac cells, we investigated the role of prokineticin-2 on capillary endothelial cell and cardiomyocyte function. In cultured cardiac endothelial cells, prokineticin-2 or overexpression of PKR1 induces vessel-like formation without increasing VEGF levels. In cardiomyocytes and H9c2 cells, prokineticin-2 or overexpressing PKR1 activates Akt to protect cardiomyocytes against oxidative stress. The survival and angiogenesis promoting effects of prokineticin-2 in cardiac cells were completely reversed by siRNA-PKR1, indicating PKR1 involvement. We thus, further investigated whether intramyocardial gene transfer of DNA encoding PKR1 may rescue the myocardium against myocardial infarction in mouse model. Transient PKR1 gene transfer after coronary ligation reduces mortality and preserves left ventricular function by promoting neovascularization and protecting cardiomyocytes without altering VEGF levels. In human end-stage failing heart samples, reduced PKR1 and prokineticin-2 transcripts and protein levels implicate a more important role for prokineticin-2/PKR1 signaling in heart. Our results suggest that PKR1 may represent a novel therapeutic target to limit myocardial injury following ischemic events.

G alpha 12/13- and reactive oxygen species-dependent activation of c-Jun NH2-terminal kinase and p38 mitogen-activated protein kinase by angiotensin receptor stimulation in rat neonatal cardiomyocytes.

In the present study, we examined signal transduction mechanism of reactive oxygen species (ROS) production and the role of ROS in angiotensin II-induced activation of mitogen-activated protein kinases (MAPKs) in rat neonatal cardiomyocytes. Among three MAPKs, c-Jun NH(2)-terminal kinase (JNK) and p38 MAPK required ROS production for activation, as an NADPH oxidase inhibitor, diphenyleneiodonium, inhibited the activation. The angiotensin II-induced activation of JNK and p38 MAPK was also inhibited by the expression of the Galpha(12/13)-specific regulator of G protein signaling (RGS) domain, a specific inhibitor of Galpha(12/13), but not by an RGS domain specific for Galpha(q). Constitutively active Galpha(12)- or Galpha(13)-induced activation of JNK and p38 MAPK, but not extracellular signal-regulated kinase (ERK), was inhibited by diphenyleneiodonium. Angiotensin II receptor stimulation rapidly activated Galpha(13), which was completely inhibited by the Galpha(12/13)-specific RGS domain. Furthermore, the Galpha(12/13)-specific but not the Galpha(q)-specific RGS domain inhibited angiotensin II-induced ROS production. Dominant negative Rac inhibited angiotensin II-stimulated ROS production, JNK activation, and p38 MAPK activation but did not affect ERK activation. Rac activation was mediated by Rho and Rho kinase, because Rac activation was inhibited by C3 toxin and a Rho kinase inhibitor, Y27632. Furthermore, angiotensin II-induced Rho activation was inhibited by Galpha(12/13)-specific RGS domain but not dominant negative Rac. An inhibitor of epidermal growth factor receptor kinase AG1478 did not affect angiotensin II-induced JNK activation cascade. These results suggest that Galpha(12/13)-mediated ROS production through Rho and Rac is essential for JNK and p38 MAPK activation.