Feeding enhances fibronectin adherence of quiescent lymphocytes through non-canonical insulin signalling.

Nutritional availability during fasting and refeeding affects the temporal redistribution of lymphoid and myeloid immune cells among the circulating and tissue-resident pools. Conversely, nutritional imbalance and impaired glucose metabolism are associated with chronic inflammation, aberrant immunity and anomalous leukocyte trafficking. Despite being exposed to periodic alterations in blood insulin levels upon fasting and feeding, studies exploring the physiological effects of these hormonal changes on quiescent immune cell function and trafficking are scanty. Here, we report that oral glucose load in mice and healthy men enhances the adherence of circulating peripheral blood mononuclear cells (PBMCs) and lymphocytes to fibronectin. Adherence to fibronectin is also observed upon regular intake of breakfast following overnight fasting in healthy subjects. This glucose load-induced phenomenon is abrogated in streptozotocin-injected mice that lack insulin. Intra-vital microscopy in mice demonstrated that oral glucose feeding enhances the homing of PBMCs to injured blood vessels in vivo. Furthermore, employing flow cytometry, Western blotting and adhesion assays for PBMCs and Jurkat-T cells, we elucidate that insulin enhances fibronectin adherence of quiescent lymphocytes through non-canonical signalling involving insulin-like growth factor-1 receptor (IGF-1R) autophosphorylation, phospholipase C gamma-1 (PLCγ-1) Tyr783 phosphorylation and inside-out activation of ß-integrins respectively. Our findings uncover the physiological relevance of post-prandial insulin spikes in regulating the adherence and trafficking of circulating quiescent T-cells through fibronectin-integrin interaction.

Musashi-2 causes cardiac hypertrophy and heart failure by inducing mitochondrial dysfunction through destabilizing Cluh and Smyd1 mRNA.

Regulation of RNA stability and translation by RNA-binding proteins (RBPs) is a crucial process altering gene expression. Musashi family of RBPs comprising Msi1 and Msi2 is known to control RNA stability and translation. However, despite the presence of MSI2 in the heart, its function remains largely unknown. Here, we aim to explore the cardiac functions of MSI2. We confirmed the presence of MSI2 in the adult mouse, rat heart, and neonatal rat cardiomyocytes. Furthermore, Msi2 was significantly enriched in the heart cardiomyocyte fraction. Next, using RNA-seq data and isoform-specific PCR primers, we identified Msi2 isoforms 1, 4, and 5, and two novel putative isoforms labeled as Msi2 6 and 7 to be expressed in the heart. Overexpression of Msi2 isoforms led to cardiac hypertrophy in cultured cardiomyocytes. Additionally, Msi2 exhibited a significant increase in a pressure-overload model of cardiac hypertrophy. We selected isoforms 4 and 7 to validate the hypertrophic effects due to their unique alternative splicing patterns. AAV9-mediated overexpression of Msi2 isoforms 4 and 7 in murine hearts led to cardiac hypertrophy, dilation, heart failure, and eventually early death, confirming a pathological function for Msi2. Using global proteomics, gene ontology, transmission electron microscopy, seahorse, and transmembrane potential measurement assays, increased MSI2 was found to cause mitochondrial dysfunction in the heart. Mechanistically, we identified Cluh and Smyd1 as direct downstream targets of Msi2. Overexpression of Cluh and Smyd1 inhibited Msi2-induced cardiac malfunction and mitochondrial dysfunction. Collectively, we show that Msi2 induces hypertrophy, mitochondrial dysfunction, and heart failure.

Inhibition of poly (ADP-ribose) Polymerase-1 (PARP-1) improves endothelial function in pulmonary hypertension.

Endothelial dysfunction is critical in the pulmonary vasculature during pulmonary hypertension (PH). Moreover, in PH, increased inflammation and oxidative/nitrosative stress cause DNA damage, activating poly (ADP-ribose) polymerase-1 (PARP-1). Meloche et al. (2014) and our previous research have shown that inhibiting PARP-1 is protective in PH and associated RV hypertrophy. However, the role of PARP-1 in pulmonary arterial endothelial dysfunction has not been explored completely. Therefore, the current study aims to investigate the involvement of PARP-1 in endothelial dysfunction associated with PH. Hypoxia (1% O2) was used to induce a PH-like phenotype in human pulmonary artery endothelial cells (HPAECs), and PARP-1 inhibition was achieved via siRNA (60 nM). For the in vivo study, male Sprague Dawley rats were administered monocrotaline (MCT; 60 mg/kg, SC, once) to induce PH, and 1, 5-isoquinolinediol (ISO; 3 mg/kg) was administered daily intraperitoneally to inhibit PARP-1. PARP-1 inhibition decreased proliferation and inflammation, as well as improved mitochondrial dysfunction in hypoxic HPAECs. Furthermore, PARP-1 inhibition also promoted apoptosis by increasing DNA damage in hypoxic HPAECs. In addition, inhibition of PARP-1 reduced cell migration, VEGF expression, and tubule formation in hypoxic HPAECs. In in vivo studies, PARP-1 inhibition by ISO significantly decreased the RVP and RVH as well as improved endothelial function by increasing the pulmonary vascular reactivity and expression of p-eNOS in MCT-treated rats.

Pyrroloquinoline quinone (PQQ) improves pulmonary hypertension by regulating mitochondrial and metabolic functions.

Excessive proliferation of pulmonary artery smooth muscle cells (PASMCs) and endothelial cells (PAECs), inflammation, as well as mitochondrial and metabolic dysregulation, contributes to the development of pulmonary hypertension (PH). Pyrroloquinoline quinone (PQQ), a potent natural antioxidant with anti-diabetic, neuroprotective, and cardioprotective properties, is known to promote mitochondrial biogenesis. However, its effect on cellular proliferation, apoptosis resistance, mitochondrial and metabolic alterations associated with PH remains unexplored. The current study was designed to investigate the effect of PQQ in the treatment of PH. Human pulmonary artery smooth muscle cells (HPASMCs), endothelial cells (PAECs), and primary cultured cardiomyocytes were subjected to hypoxia to induce PH-like phenotype. Furthermore, Sprague Dawley (SD) rats injected with monocrotaline (MCT) (60 mg/kg, SC, once) progressively developed pulmonary hypertension. PQQ treatment (2 mg/kg, PO, for 35 days) attenuated cellular proliferation and promoted apoptosis via a mitochondrial-dependent pathway. Furthermore, PQQ treatment in HPASMCs prevented mitochondrial and metabolic dysfunctions, improved mitochondrial bioenergetics while preserving respiratory complexes, and reduced insulin resistance. In addition, PQQ treatment (preventive and curative) significantly attenuated the increase in right ventricle pressure and hypertrophy as well as reduced endothelial dysfunction and pulmonary artery remodeling in MCT-treated rats. PQQ also prevented cardiac fibrosis and improved cardiac functions as well as reduced inflammation in MCT-treated rats. Altogether, the above findings demonstrate that PQQ can attenuate mitochondrial as well as metabolic abnormalities in PASMCs and also prevent the development of PH in MCT treated rats; hence PQQ may act as a potential therapeutic agent for the treatment of PH.

Modulation of Insulin Resistance, Dyslipidemia and Serum Metabolome in iNOS Knockout Mice following Treatment with Nitrite, Metformin, Pioglitazone, and a Combination of Ampicillin and Neomycin.

Oxidative and nitrosative stress plays a pivotal role in the incidence of metabolic disorders. Studies from this lab and others in iNOS-/- mice have demonstrated occurrence of insulin resistance (IR), hyperglycemia and dyslipidemia highlighting the importance of optimal redox balance. The present study evaluates role of nitrite, L-arginine, antidiabetics (metformin, pioglitazone) and antibiotics (ampicillin-neomycin combination, metronidazole) on metabolic perturbations observed in iNOS-/- mice. The animals were monitored for glucose tolerance (IPGTT), IR (insulin, HOMA-IR, QUICKI), circulating lipids and serum metabolomics (LC-MS). Hyperglycemia, hyperinsulinemia and IR were rescued by nitrite, antidiabetics, and antibiotics treatments in iNOS-/- mice. Glucose intolerance was improved with nitrite, metformin and pioglitazone treatment, while ampicillin-neomycin combination normalised the glucose utilization in iNOS-/- mice. Increased serum phosphatidylethanolamine lipids in iNOS-/- mice were reversed by metformin, pioglitazone and ampicillin-neomycin; dyslipidemia was however marginally improved by nitrite treatment. The metabolic improvements were associated with changes in selected serum metabolites-purines, ceramide, 10-hydroxydecanoate, glucosaminate, diosmetin, sebacic acid, 3-nitrotyrosine and cysteamine. Bacterial metabolites-hippurate, indole-3-ethanol; IR marker-aminoadipate and oxidative stress marker-ophthalmate were reduced by pioglitazone and ampicillin-neomycin, but not by nitrite and metformin treatment. Results obtained in the present study suggest a crucial role of gut microbiota in the metabolic perturbations observed in iNOS-/- mice.

Proinflammatory Effect of Endothelial Microparticles Is Mitochondria Mediated and Modulated Through MAPKAPK2 (MAPK-Activated Protein Kinase 2) Leading to Attenuation of Cardiac Hypertrophy.

Objective- This study investigates the functional significance of mitochondria present in endothelial microparticles (EMP) and how MK2 (MAPKAPK2 [MAPK-activated protein kinase 2]) governs EMP production and its physiological effect on cardiac hypertrophy. Approach and Results- Flow cytometric analysis, confocal imaging, oxygen consumption rate measurement through Seahorse were used to confirm the presence of functionally active mitochondria in nontreated EMP (EMP derived from untreated control cells), lipopolysaccharide, and oligomycin treatment increased mitochondrial reactive oxygen species activity in EMP (EMP derived from cells treated with lipopolysaccharide and EMP derived from cells treated with oligomycin, respectively). The dysfunctional mitochondria contained in EMP derived from cells treated with lipopolysaccharide and EMP derived from cells treated with oligomycin induced the expression of proinflammatory mediators in the target endothelial cells leading to the augmented adhesion of human monocytic cell line on EA.hy926 cells. Multiphoton real-time imaging detected the increased adherence of EMP derived from cells treated with oligomycin at the site of carotid artery injury as compared to EMP derived from untreated control cells. MK2 regulates EMP generation during inflammation by reducing E-selectin expression and regulating the cytoskeleton rearrangement through ROCK-2 (Rho-associated coiled-coil containing protein kinase 2) pathway. MK2-deficient EMP reduced the E-selectin and ICAM-1 (intracellular adhesion molecule-1) expression on target endothelial cells leading to reduced monocyte attachment and reduced cardiac hypertrophy in mice. Conclusions- MK2 promotes the proinflammatory effect of EMP mediated through dysfunctional mitochondria. MK2 modulates the inflammatory effect induced during cardiac hypertrophy through EMP.

Involvement of fatty acid synthase in right ventricle dysfunction in pulmonary hypertension.

Apart from pulmonary vascular resistance and right ventricle (RV) hypertrophy, metabolic dysfunction also plays a major role in pathophysiology of pulmonary hypertension (PH). Recently, we have shown that fatty acid synthase (FAS), an enzyme involved in de novo fatty acid synthesis, plays a pivotal role in PH as its inhibition was protective and decreased pulmonary vascular remodelling, RV pressure and hypertrophy and improved endothelial functions. However, the precise mechanism behind protective effect of FAS inhibition on right ventricle dysfunction associated with PH is not completely understood. Therefore, the present study delineated the mechanism of protective effect of FAS inhibition on RV dysfunction associated with PH. siRNA mediated inhibition of FAS reduced FAS expression, hypertrophy, inflammation, apoptosis, autophagy and improved the glucose oxidation, mitochondrial membrane potential and ATP level in hypoxic cardiomyocytes. In monocrotaline (MCT) treated rats, FAS inhibition by C75 (2 mg/kg, i.p., once a week from 21 to 35 days) decreased the expression and activity of FAS and palmitate level. C75 also improved cardiac functions and mitochondrial membrane potential leading to decreased apoptosis in RV of MCT treated rats. In conclusion, our study reveals that inhibition of FAS decreases RV hypertrophy and improves cardiac function associated with PH by perking up metabolic functions.

Reversal of Osteopenia in Ovariectomized Rats by Pentoxifylline: Evidence of Osteogenic and Osteo-Angiogenic Roles of the Drug.

Pentoxifylline (PTX) is a non-selective phosphodiesterase inhibitor and is used for the management of intermittent claudication. We tested whether PTX has oral efficacy in stimulating new bone formation. Rat calvarial osteoblasts (RCO) were used to study the effect of PTX on osteoblast differentiation and angiogenesis. Pharmacokinetic and pharmacodynamic studies were carried out in rats to determine an oral dose of PTX. In ovariectomized (OVX) rats with osteopenia, the effect of PTX on various skeletal parameters was studied, and compared with teriparatide. Effect of PTX on angiogenic signaling was studied by immunoblotting and relevant pharmacologic inhibitors. Bone vascularity was measured by intravenous injection of polystyrene fluorospheres followed by in vivo imaging, and angiogenesis was studied in vitro by tubulogenesis of endothelial cells and in vivo by Matrigel plug assay. Effective concentration (EC50) of PTX in RCO was 8.2 nM and plasma PTX level was 7 nM/mL after single oral dosing of 25 mg/kg, which was 1/6th the clinically used dose. At this dose, PTX enhanced bone regeneration at femur osteotomy site and completely restored bone mass, microarchitecture, and strength in OVX rats. Furthermore, PTX increased surface referent bone formation parameters and serum bone formation marker (PINP) without affecting the resorption marker (CTX-1). PTX increased the expression of vascular endothelial growth factor and its receptor in bones and osteoblasts. PTX also increased skeletal vascularity, tubulogenesis of endothelial cells and in vivo angiogenesis. Taken together, our study suggested that PTX at 16% of adult human oral dose completely reversed osteopenia in OVX rats by osteogenic and osteo-angiogenic mechanisms.

Antihypertensive Drugs Aliskiren, Nebivolol, and Olmesartan Reduce Hypertension by Reducing Endothelial Microparticles and Regulating Angiogenesis.

The accelerated generation of endothelial microparticles (EMPs) and impaired angiogenesis are the markers of vascular pathology during various cardiovascular and inflammatory conditions including hypertension. Because studies comparing the effects of antihypertensive agents on these 2 parameters are limited, this study was designed to compare the effects of 3 antihypertensive agents: aliskiren, nebivolol, and olmesartan, on the EMP generation and angiogenesis. Changes in the hemodynamic parameters and serum EMP count were determined after 3 weeks of the drug treatments [aliskiren (30 mg/kg), nebivolol (10 mg/kg), or olmesartan (5 mg/kg) per orally] in L-NAME-induced rat model of hypertension. The 3 drugs prevented the rise in blood pressure and EMP count to a similar extent. Furthermore, nebivolol was found to possess more potent and concentration-dependent antiangiogenic activity compared with aliskiren, whereas olmesartan was devoid of such an effect. The EMPs generated by virtue of the respective drug treatments were found to be involved in mediating the antiangiogenic effect of nebivolol and aliskiren. In addition, olmesartan treatment also resulted in the increased eNOS expression. The results of this study show that the antihypertensive drugs, viz. aliskiren, nebivolol, and olmesartan, regulate the vascular health by their differential effects on the EMP generation and angiogenesis.

Curcuma oil reduces endothelial cell-mediated inflammation in postmyocardial ischemia/reperfusion in rats.

Endothelial cells initiated inflammation persisting in postmyocardial infarction needs to be controlled and moderated for avoiding fatal complications. Curcuma oil (C.oil, Herbal Medicament), a standardized hexane soluble fraction of Curcuma longa has possessed neuroprotective effect. However, its effect on myocardial ischemia/reperfusion (MI/RP) and endothelial cells remains incompletely defined. Here, using in vivo rat MI/RP injury model and in vitro cellular approaches using EA.hy926 endothelial cells, enzyme-linked immunosorbent assay, real-time polymerase chain reaction, and myograph, we provide evidence that with effective regimen and preconditioning of rats with C.oil (250 mg/kg, PO), before and after MI/RP surgery protects rats from MI/RP-induced injury. C.oil treatment reduces left ventricular ischemic area and endothelial cell-induced inflammation, specifically in the ischemic region (*P < 0.0001) and improved endothelial function by reducing the expression of proinflammatory genes and adhesion factors on endothelial cells both in vitro and in vivo. Furthermore, mechanistic studies have revealed that C.oil reduced the expression of adhesion factors like E-selectin (#P = 0.0016) and ICAM-1 ($P = 0.0069) in initiating endothelial cells-induced inflammation. In line to the real-time polymerase chain reaction expression data, C.oil reduced the adhesion of inflammatory cells to endothelial cells as assessed by the interaction of THP-1 monocytes with the endothelial cells using flow-based adhesion and under inflammatory conditions. These studies provide evidence that salutary effect of C.oil on MI/RP could be achieved with pretreatment and posttreatment of rats, C.oil reduced MI/RP-induced injury by reducing the endothelial cell-mediated inflammation, specifically in the ischemic zone of MI/RP rat heart.

Androsin alleviates non-alcoholic fatty liver disease by activating autophagy and attenuating de novo lipogenesis.

BACKGROUND: Non-alcoholic fatty liver disease (NAFLD) is a chronic liver disease with therapeutic options on the horizon. Picrorhiza kurroa, enriched with iridoid glycosides like picroside I and picroside II is known for its hepatoprotective activity and anti-inflammatory properties. Androsin, the other phytochemical present in P. kurroa has been shown to have anti-inflammatory and anti-asthmatic properties. However, its role in NAFLD is yet to be investigated. PURPOSE: This study aims to identify the potent hepatoprotective agent from P. kurroa that can attenuate NAFLD in HFrD-fed ApoE-/- mice, and elucidate the underlying mechanisms governing its effects. METHODS: Classical purification methods were used to isolate seven compounds, including picroside I, picroside II and androsin from the roots of P. kurroa. NAFLD-induced ApoE-/- mice were administered orally with either picroside I, picroside II, or androsin for 7 weeks. Animals were scanned non-invasively by ultrasonography at 1st and 14th week. Gross histomorphometry was examined by HE and Sirius red staining. mRNA transcript and protein profile associated with autophagy, lipogenesis, inflammation, and fibrosis was done through RT-PCR and Western blot analysis. RESULTS: In-vitro and in-vivo studies revealed that among the seven evaluated compounds, androsin shows the most potent in-vitro activity. Oral dosing of androsin (10 mg/kg) protected the liver against HFrD-induced NAFLD in ApoE-/- mice model. Biochemical analysis revealed a reduction in ALT and AST enzymes and a significant reduction in cholesterol levels. Hepatocyte ballooning, hepatic lipid deposition, inflammation, and fibrosis were reduced. Androsin treatment significantly reduced fibrosis (α-SMA, collagens, TGF-ß) and inflammation (ILs, TNF-α, NFκB) in ApoE-/- mice. Mechanistically, androsin activated AMPKα and down-regulated the expression of SREBP-1c, resulting in ameliorating hepatic lipogenesis. CONCLUSION: Our results support autophagy as one of the therapeutic strategies to reduce steatosis and hepatic damage. We found that androsin treatment significantly ameliorated hepatic steatosis, serum lipid levels, and hepatic injury in ApoE-/- induced by HFrD. Androsin administration mitigated lipogenesis by inhibiting SREBP1c/FASN pathway and activating autophagy through AMPKα/PI3K/Beclin1/LC3 pathway.

Ameliorating impaired cardiac function in myocardial infarction using exosome-loaded gallic-acid-containing polyurethane scaffolds.

Myocardial infarction (MI) can be tackled by implanting cardiac patches which provide mechanical support to the heart. However, most tissue-engineered scaffolds face difficulty in attenuating oxidative stress, maintaining mechanical stability, and regenerating damaged cardiomyocytes. Here, we fabricated elastic cryogels using polyurethane modified with antioxidant gallic acid in its backbone (PUGA) and further coated them with decellularized extracellular matrix (dECM) to improve adhesiveness, biocompatibility and hemocompatibility. The scaffold was functionalized with exosomes (EXO) isolated from adipose-derived stem cells having regenerative potential. PUGA-dECM + EXO was tested in a rat model with induced MI where echocardiography after 8 weeks of implantation showed significant recovery in treatment group. Histological analysis revealed a decrease in fibrosis after application of patch and promotion of angiogenesis with reduced oxidative stress was shown by immunostaining. Expression of cardiac tissue contractile function marker was also observed in treatment groups. Thus, the proposed biomaterial has a promising application to be utilized as a patch for cardiac regeneration. More detailed studies with larger animal species are needed for using these observations for specific applications.

Functionalized azirine based scaffolds as endothelin inhibitors for the selective anti-angiogenic activity.

Anti-angiogenic therapy has long been used as an adjunct therapy for the resolution of tumor burden. The current findings describe the synthesis of novel marine-based azirine-containing compounds that exhibit anti-angiogenic mediated anti-tumor activity. Azirine-2-carboxylate inhibited HUVEC-mediated tubulogenesis without causing cell death in a dose-dependent manner. Ex-vivo CAM, in-vivo Matrigel implantation, and ear angiogenesis experiments have all shown that azirine-2-carboxylate effectively inhibits angiogenesis. Furthermore, azirine-2-carboxylate inhibits the migration of ECs without disrupting the preformed tubule network. Azirine-2-carboxylate had adequate intramuscular systemic exposure and inhibited tumor growth in a xenograft mouse model. DARTS analysis, competitive binding assay, and gene expression investigations revealed that azirine-2-carboxylate inhibits endothelin-1-mediated angiogenesis. Overall, the discovery of azirine-2-carboxylate demonstrated a potent inhibition of angiogenesis targeting ET1 and a possible application in anti-angiogenic therapy.

Signal transducer of inflammation gp130 modulates atherosclerosis in mice and man.

Liver-derived acute phase proteins (APPs) emerged as powerful predictors of cardiovascular disease and cardiovascular events, but their functional role in atherosclerosis remains enigmatic. We report that the gp130 receptor, which is a key component of the inflammatory signaling pathway within hepatocytes, influences the risk of atherosclerosis in a hepatocyte-specific gp130 knockout. Mice on an atherosclerosis-prone genetic background exhibit less aortic atherosclerosis (P < 0.05) with decreased plaque macrophages (P < 0.01). Translating these findings into humans, we show that genetic variation within the human gp130 homologue, interleukin 6 signal transducer (IL6ST), is significantly associated with coronary artery disease (CAD; P < 0.05). We further show a significant association of atherosclerotic disease at the ostium of the coronary arteries (P < 0.005) as a clinically important and heritable subphenotype in a large sample of families with myocardial infarction (MI) and a second independent population-based cohort. Our results reveal a central role of a hepatocyte-specific, gp130-dependent acute phase reaction for plaque development in a murine model of atherosclerosis, and further implicate IL6ST as a genetic susceptibility factor for CAD and MI in humans. Thus, the acute phase reaction should be considered an important target for future drug development in the management of CAD.

Involvement of HIF1α/Reg protein in the regulation of HMGB3 in myocardial infarction.

AIMS: Myocardial ischemia and infarction are the number one cause of cardiovascular disease associated mortality. Cardiomyocyte death during ischemia leads to the loss of cardiac tissue and initiates a signaling cascade between the infarct zone and the area at risk of the myocardium. Here, we sought to determine the involvement of one of the damage-associated molecular patterns HMGB3 in myocardial ischemia and infarction. METHODS AND RESULTS: We used the left anterior descending coronary artery ligation model to study the involvement of HMGB3 in myocardial ischemia and infarction. Our results indicated the presence of HMGB3 at a low level under normal conditions, while myocardial injury caused a robust increase in HMGB3 levels in the heart. Further, intra-cardiac injection of mabHMGB3 had improved cardiac function at day 3 by downregulating HMGB3 levels. In contrast, injection of recombinant rat HMGB3 for 7 days during the adaptation phase of myocardial ischemia improved cardiac functional parameters by increasing regenerative protein family expression. Further, to mimic the disease condition, neonatal rat ventricle cardiomyocytes and fibroblasts were exposed to hypoxia; we observed a significant upregulation in the HMGB3, HIF1α, and Reg1α levels. Endothelial cells exposed to recombinant HMGB3 increased the tubule length. Further, the mitochondrial oxygen consumption rate was reduced with the acute induction of recombinant HMGB3 on cardiomyocytes and fibroblasts. CONCLUSION: HMGB3 plays a dual role during the progression of myocardial ischemia and infarction. Clinically, post-myocardial infarction HMGB3-induced sterile inflammation needs to be tightly controlled, as it plays both a pro-inflammatory role and improves cardiac function during the cardiac remodeling phase.

Ormeloxifene, a selective estrogen receptor modulator, protects against pulmonary hypertension.

PURPOSE: Protective effect of 17ß-estradiol is well-known in pulmonary hypertension. However, estrogen-based therapy may potentially increase the risk of breast cancer, necessitating a search for novel drugs. This study, therefore, investigated the ameliorative effects of a selective estrogen receptor modulator, ormeloxifene, in pulmonary hypertension. METHODS: Cardiomyocytes (H9C2) and human pulmonary arterial smooth muscle cells (HPASMCs) were exposed to hypoxia (1% O2) for 42 and 96 h, respectively, with or without ormeloxifene pre-treatment (1 µM). Also, female (ovary-intact or ovariectomized) and male Sprague-Dawley rats received monocrotaline (60 mg/kg, once, subcutaneously), with or without ormeloxifene treatment (2.5 mg/kg, orally) for four weeks. RESULTS: Hypoxia dysregulated 17ß-hydroxysteroid dehydrogenase (17ßHSD) 1 & 2 expressions, reducing 17ß-estradiol production and estrogen receptors α and ß in HPASMC but increasing estrone, proliferation, inflammation, oxidative stress, and mitochondrial dysfunction. Similarly, monocrotaline decreased plasma 17ß-estradiol and uterine weight in ovary-intact rats. Further, monocrotaline altered 17ßHSD1 & 2 expressions and reduced estrogen receptors α and ß, increasing right ventricular pressure, proliferation, inflammation, oxidative stress, endothelial dysfunction, mitochondrial dysfunction, and vascular remodeling in female and male rats, with worsened conditions in ovariectomized rats. Ormeloxifene was less uterotrophic; however, it attenuated both hypoxia and monocrotaline effects by improving pulmonary 17ß-estradiol synthesis. Furthermore, ormeloxifene decreased cardiac hypertrophy and right ventricular remodeling induced by hypoxia and monocrotaline. CONCLUSION: This study demonstrates that ormeloxifene promoted pulmonary 17ß-estradiol synthesis, alleviated inflammation, improved the NOX4/HO1/Nrf/PPARγ/PGC-1α axis, and attenuated pulmonary hypertension. It is evidently safe at tested concentrations and may be effectively repurposed for pulmonary hypertension treatment.

Intestinal decontamination inhibits TLR4 dependent fibronectin-mediated cross-talk between stellate cells and endothelial cells in liver fibrosis in mice.

BACKGROUND & AIMS: Liver fibrosis is associated with angiogenesis and leads to portal hypertension. Certain antibiotics reduce complications of liver failure in humans, however, the effects of antibiotics on the pathologic alterations of the disease are not fully understood. The aim of this study was to test whether the non-absorbable antibiotic rifaximin could attenuate fibrosis progression and portal hypertension in vivo, and explore potential mechanisms in vitro. METHODS: The effect of rifaximin on portal pressure, fibrosis, and angiogenesis was examined in wild type and Toll-like receptor 4 (TLR4) mutant mice after bile duct ligation (BDL). In vitro studies were carried out to evaluate the effect of the bacterial product and TLR agonist lipopolysaccharide (LPS) on paracrine interactions between hepatic stellate cells (HSC) and liver endothelial cells (LEC) that lead to fibrosis and portal hypertension. RESULTS: Portal pressure, fibrosis, and angiogenesis were significantly lower in BDL mice receiving rifaximin compared to BDL mice receiving vehicle. Studies in TLR4 mutant mice confirmed that the effect of rifaximin was dependent on LPS/TLR4 pathway. Fibronectin (FN) was increased in the BDL liver and was reduced by rifaximin administration and thus, was explored further in vitro as a potential mediator of paracrine interactions of HSC and LEC. In vitro, LPS promoted FN production from HSC. Furthermore, HSC-derived FN promoted LEC migration and angiogenesis. CONCLUSIONS: These studies expand our understanding of the relationship of intestinal microbiota with fibrosis development by identifying FN as a TLR4 dependent mediator of the matrix and vascular changes that characterize cirrhosis.

Aquaporin-1 promotes angiogenesis, fibrosis, and portal hypertension through mechanisms dependent on osmotically sensitive microRNAs.

Changes in hepatic vasculature accompany fibrogenesis, and targeting angiogenic molecules often attenuates fibrosis in animals. Aquaporin-1 (AQP1) is a water channel, overexpressed in cirrhosis, that promotes angiogenesis by enhancing endothelial invasion. The effect of AQP1 on fibrogenesis in vivo and the mechanisms driving AQP1 expression during cirrhosis remain unclear. The purpose of this study was to test the effect of AQP1 deletion in cirrhosis and explore mechanisms regulating AQP1. After bile duct ligation, wild-type mice overexpress AQP1 that colocalizes with vascular markers and sites of robust angiogenesis. AQP1 knockout mice demonstrated reduced angiogenesis compared with wild-type mice, as evidenced by immunostaining and endothelial invasion/proliferation in vitro. Fibrosis and portal hypertension were attenuated based on immunostaining, portal pressure, and spleen/body weight ratio. AQP1 protein, but not mRNA, was induced by hyperosmolality in vitro, suggesting post-transcriptional regulation. Endothelial cells from normal or cirrhotic mice were screened for microRNA (miR) expression using an array and a quantitative PCR. miR-666 and miR-708 targeted AQP1 mRNA and were decreased in cirrhosis and in cells exposed to hyperosmolality, suggesting that these miRs mediate osmolar changes via AQP1. Binding of the miRs to the untranslated region of AQP1 was assessed using luciferase assays. In conclusion, AQP1 promotes angiogenesis, fibrosis, and portal hypertension after bile duct ligation and is regulated by osmotically sensitive miRs.

Serum and cecal metabolic profile of the insulin resistant and dyslipidemic p47phox knockout mice.

Involvement of NOX-dependent oxidative stress in the pathophysiology of metabolic disorders as well as in the maintenance of metabolic homeostasis has been demonstrated previously. In the present study, the metabolic profile in p47phox-/- and WT mice fed on a chow diet was evaluated to assess the role of metabolites in glucose intolerance and dyslipidemia under altered oxidative stress conditions. p47phox-/- mice displayed glucose intolerance, dyslipidemia, hyperglycemia, insulin resistance (IR), hyperinsulinemia, and altered energy homeostasis without any significant change in gluconeogenesis. The expression of genes involved in lipid synthesis and uptake was enhanced in the liver, adipose tissue, and intestine tissues. Similarly, the expression of genes associated with lipid efflux in the liver and intestine was also enhanced. Enhanced gut permeability, inflammation, and shortening of the gut was evident in p47phox-/- mice. Circulating levels of pyrimidines, phosphatidylglycerol lipids, and 3-methyl-2-oxindole were augmented, while level of purine was reduced in the serum. Moreover, the cecal metabolome was also altered, as was evident with the increase in indole-3-acetamide, N-acetyl galactosamine, glycocholate, and a decrease in hippurate, indoxyl sulfate, and indigestible sugars (raffinose and melezitose). Treatment of p47phox-/- mice with pioglitazone, marginally improved glucose intolerance, and dyslipidemia, with an increase in PUFAs (linoleate, docosahexaenoic acid, and arachidonic acid). Overall, the results obtained in p47phox-/- mice indicate an association of IR and dyslipidemia with altered serum and cecal metabolites (both host and bacterial-derived), implying a critical role of NOX-derived ROS in metabolic homeostasis.

Fabrication, characterization and in vivo assessment of cardiogel loaded chitosan patch for myocardial regeneration.

Cell therapy is one of the promising approaches for cardiac repair, subsequently after infarction or injury. However, contemporary mesenchymal stromal/stem cell (MSCs) delivery strategies result in low retention and poor engraftment of donor cells, thus limiting the therapeutic efficacy. Here, we developed an engineered biomimetic cardiogel patch (EBCP) comprising of the native decellularized cardiac extracellular matrix (ECM) "cardiogel" and chitosan, leading to the efficient regeneration of injured myocardium. We also developed novel bio-adhesive that is capable of suture-free epicardial placement of EBCP to injured myocardium. We have illustrated the potential of the mussels-inspired bioadhesive system, which comprises gelatin catechol and partially oxidized chitosan, which relies on self-crosslinking capability, to promote wet adhesion. In vitro studies with isolated cardiogel promoted cell proliferation, adhesion, and migration while aiding cardiomyogenic differentiation. The EBCP's ability to protect cells from abrasion due to surrounding tissues in the myocardial infarction (MI) rat model makes it more desirable. Furthermore, the epicardial implantation of the EBCP loaded with MSCs improves the initial retention of cells and subsequent functional cardiac recovery with enhanced myocardial tissue restoration. Histological examination showed the presence of EBCP and infiltration of cells to the infarcted heart tissue. The fast and facile synthesis of bioadhesive and major therapeutic benefits of EBCP make it a potential candidate for recuperating the ailing heart.