Phenylephrine attenuates LPS-induced lung injury via Foxh1/GSK-3β/β-catenin-mediated alveolar epithelial cell differentiation in ARDS.

SIRT4-mediated debutyrylation of SUCLG1 rescues myocardial energy failure in HFpEF: Ginsenoside Rb3 as a novel SIRT4-interacting regulator.

Hypotension, or low mean arterial blood pressure (MAP), has been associated with adverse outcomes in perioperative patients. A primary goal of treating hypotension during surgery is to preserve vital organ perfusion by maintaining intravascular volume and the use of vasoactive medications, including phenylephrine (PE), to support MAP. Phenylephrine, a vasoconstrictor with α1-adrenergic agonist activity, acts on resistance arterioles and veins to increase vascular resistance and reduce venous capacitance, thereby increasing MAP. It predominantly acts on skeletal muscle resistance arterioles, but concerns have been raised about its potential negative impact on brain and revascularized muscle flap perfusion. We conducted an in vivo animal study using translational rodent models. Measuring microvascular blood flow (laser Doppler) and partial pressure of oxygen (PO2) (phosphorescence quenching of oxygen) in rats (total N = 48), we sought to test the hypothesis that PE produces differential effects on brain, skeletal muscle, and skeletal muscle flap perfusion. Treatment of hypotension with PE increased MAP, brain microvascular blood flow, and brain tissue PO2, at the expense of reduced skeletal muscle microvascular blood flow. Escalating doses of PE reduced skeletal muscle microvascular blood flow without reducing tissue PO2. Tissue blood flow and PO2 were severely reduced in skeletal muscle free flaps at baseline, without any further reduction after exposure to escalating doses of PE. Elevation of the hypoxic cellular protein hypoxia-inducible factor 1α (HIF-1α) in muscle free flaps provided evidence of severe tissue hypoxia in viable muscle flap tissue. These data may inform the optimal use of PE to restore MAP to ensure optimal brain tissue perfusion. Use of tissue oximetry may ensure the adequacy of tissue perfusion in perioperative patients.

Recent studies show that telomerase reverse transcriptase (TERT) possesses important new biological functions in gene transcription regulation, signal transduction, tumorigenesis, vascular development and mitochondrial DNA protection independent of the maintenance of telomere length. In this study we investigated the role and mechanisms of TERT in regulating the gene expression and signal transduction during pressure overload-induced cardiac remodeling. The first-generation TERT knockout (Tert-/-) and wild-type littermate control (Tert+/+) male mice were subjected to transverse aortic constriction (TAC) surgery to establish a pressure overload-induced cardiac remodeling model. We showed that pressure overload significantly increased TERT expression in the hearts at 8 weeks after TAC, whereas TERT deficiency remarkably exacerbated pressure overload-induced cardiac dysfunction, cardiac hypertrophy and fibrosis, and reduced the survival rate of the mice. In contrast, TERT overexpression reversed phenylephrine (PE)-stimulated cardiomyocyte hypertrophy and fibrosis in neonatal rat ventricular myocytes (NRVMs). Ttranscriptomic and proteomic analyses revealed that extracellular matrix (ECM)-receptor interaction was a key Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway regulated by TERT in hemodynamic overload-induced cardiac remodeling. TERT knockdown greatly enhanced, while TERT overexpression inhibited the activation of the THBS3/ITGB1 signaling pathway, in which transcription factor cellular nucleic acid-binding protein (CNBP) played a pivotal mediating role by interacting with TERT. In conclusion, the non-telomeric function of TERT in gene transcription regulation and signaling transduction plays an important role during pressure overload-induced myocardial remodeling via modulating CNBP-mediated THBS3/ITGB1 signaling pathway, which provides new targets and strategies for the prevention and treatment of pressure overload-induced cardiac remodeling.

Raloxifene is a selective estrogen receptor modulator; which plays beneficial roles in the treatment of cardiovascular diseases in women. However, its underlying mechanism remains unclear. In the present study, we investigated whether mitochondria-derived reactive oxygen species (ROS) are involved in raloxifene-induced vasodilation. Results showed that endothelium removal attenuated the vasodilatory effect of raloxifene in rat aortic rings, whereas treatment with the cyclooxygenase inhibitor indomethacin or the estrogen receptor antagonist ICI-182,780 had no significant effect, indicating that neither COX2 nor estrogen receptors are involved. The NADPH oxidase inhibitor apocynin also did not affect raloxifene-induced vasodilation. In contrast, the mitochondrial oxidase inhibitor rotenone and the mitochondrial antioxidant mito-tempo significantly attenuated raloxifene-induced vascular relaxation. In cultured vascular smooth muscle cells (VSMCs), phenylephrine (PE) markedly increased both total intracellular and mitochondrial ROS production, which was significantly inhibited by raloxifene. Accordingly, raloxifene effectively prevented the PE-induced increase in mitochondrial membrane potential, a key component of the mitochondrial electrochemical gradient. Finally, PE induced an acute decrease in uncoupling protein-2 (UCP2) expression, which was significantly prevented by raloxifene. In conclusion, this study demonstrates that raloxifene relaxes the rat aorta, at least in part, by inhibiting mitochondria-derived ROS.

Background/Objectives: Neuropathic pain (NP) affects approximately 6.9-10% of the population and is inadequately managed by the current therapies, as reflected by a high number needed to treat (NNT). These data highlight the socio-economic burden of NP on healthcare. Thus, the repurposing of existing medications and new drug combinations to enhance therapeutic efficacy are required. Methods/Results: Here, we show that intrathecal phenylephrine (PE) in a dose of 3, 10, or 30 nmol/rat acutely alleviates tactile allodynia in rats with mononeuropathic pain evoked by partial sciatic nerve ligation. Prazosin and idazoxan, which are considered as selective α1- and α2-adrenoreceptor antagonists, respectively, reversed the antiallodynic effects of PE. In ex vivo experiments, PE induced a significant cytosolic [3H]-noradrenaline release from mouse spinal tissue. In addition, in the mouse vas deferens, PE produced smooth muscle contraction in prazosin and idazoxan sensitive manner. As a novelty, in another set of experiments, oral PE (5 mg/kg) and pregabalin (PGB, 25 mg/kg) combination, but not the individual drug treatments, acutely alleviated allodynia in rats with mononeuropathy. In addition, the antiallodynic action of the combination was further enhanced upon chronic treatment. Under isoflurane anesthesia, this combination was devoid of cardiovascular side effects attributed to systolic and diastolic blood pressure, mean arterial pressure, or heart rate. PGB induced motor dysfunction was not altered upon the combination with PE. Conclusions: These data suggest that PE in combination with PGB shows promise in preclinical settings; however, the necessity for further studies is paramount to detail the pharmacokinetic interactions involved.

Background/Objectives: Molecular hydrogen (H2), a natural antioxidant, can selectively reduce hydroxyl radicals and peroxynitrite without affecting signaling molecules such as H2O2 and NO. In addition, H2 can inhibit the synthesis of inflammatory cytokines. Human and animal studies have shown that the inhalation of H2 has a hypotensive effect. In this context, the aim of the present work was to study the effect of H2 on the baroreflex regulation of blood pressure in rats with experimental monocrotaline-induced pulmonary hypertension (MCT) in vivo and the effects of H2 on the reactivity of isolated rat aorta with MCT pulmonary hypertension to α1-adrenoceptor agonists in vitro. Methods: Experiments were performed on male Wistar rats with MCT pulmonary hypertension; animals were placed in plastic chambers aerated with atmospheric air at a rate of 4 L/min with O2 and CO2 control. Cages with the rats of the MCT-H2 and Control-H2 groups were ventilated with air containing 4% H2 twice daily for 2 h each. The MCT-Air and Control-Air groups breathed only atmospheric air. The duration of the experiment was 21 days. On day 20, blood pressure and heart rate (HR) were measured in awake animals and the baroreflex response to phenylephrine (PE) and nitroprusside (NP) was tested. In in vitro experiments, we studied the effect of adding H2 to the perfusion solution on the responsiveness of isolated aortic preparations from MCT and control rats to the α1-adrenoceptor agonist PE and the vasodilators NP and Acetylcholine. Results: When the effect of H2 on the baroreflex response to NP (4.5 μg/kg) was examined in awake rats, the increase in HR was 73.1 ± 16.7 beats/min in the MCT-Air group and 48.1 ± 10.2 beats/min in the MCT-H2 group (p < 0.01). In the Control-H2 and Control-Air groups, there was a trend towards a lower HR in the Control-H2 group, but the differences were not significant. No differences in HR response to PE administration were found between any of the experimental groups. Experiments on isolated aortic preparations from MCT rats showed that the addition of H2 to the perfusion medium resulted in a 30% reduction in the maximal response to PE compared with the MCT group without hydrogen (p < 0.01), and the potency of PE (EC50) decreased threefold (p < 0.05). There was a decrease in tryptase secretion, indicating an anti-inflammatory effect of H2. Conclusions. The results demonstrate that H2 inhalation was associated with an attenuated heart rate response to nitroprusside-induced hypotension and reduced vascular reactivity to phenylephrine in rats with pulmonary hypertension.

Denopamine (DP, R(-)-1-(p-hydroxyphenyl)-2-((3,4-dimethoxyphenethyl)amino)ethanol), which has been developed as a single enantiomer from its pharmacological aspect, is a clinically useful cardiotonic drug. From our previous photostability and chiral stability studies of DP, chiral inversion of DP was observed in aqueous solutions of DP drug substances and suspensions of DP tablets under the heat stress conditions dependent on the heating temperature and the storage period. In this paper, chiral inversion mechanism of DP was investigated employing phenylephrine hydrochloride (HCl) (R (-)-form) and ephedrine HCl (1R, 2S (-)-form) as samples for comparison. These drugs have the same phenylethylamine structure and the relationship between asymmetric C-atom and N-atom is similar. As a result, phenylephrine HCl and ephedrine HCl were found to be stable for heat stress. No chiral inversion was observed in both drugs. The difference between DP and phenylephrine HCl is the bond position of the hydroxy group in the phenyl group, and the difference between DP and ephedrine HCl is the existence of the hydroxy group in the phenyl group. From this study, an important step for the chiral inversion of DP was speculated as the formation of the stable benzyl cation in DP due to its hydroxy group at para-position of the phenyl group.

Norepinephrine (NE) and phenylephrine (PE) are routinely administered vasopressors used to maintain haemodynamic stability during caesarean section. Emerging evidence suggests that sustained infusion of these agents may disrupt maternal blood glucose regulation. This randomised controlled trial aims to compare the effects of NE and PE infusion on changes in postpartum blood glucose levels, insulin concentrations and insulin resistance in women after caesarean delivery. In this double-blind, randomised trial, 100 eligible parturients will receive prophylactic intravenous infusion of either NE or PE at a rate of 30 mL/hour immediately after subarachnoid anaesthesia, continuing until the end of surgery. The primary outcome is the difference between maternal preoperative and immediate postoperative blood glucose levels. Secondary outcomes include immediate and 6-hour postoperative insulin levels, as well as Homeostasis Model Assessment of Insulin Resistance. The Institutional Ethics Committee of Xuancheng People's Hospital approved the trial protocol (ID: 2025-yjky022-02). Findings will be published in an appropriate journal, and original data will be made available in November 2029 via the ResMan primary data-sharing platform of the China Clinical Trial Registry (http://www.medresman.org.cn). ChiCTR2500107683.

Pathological cardiac hypertrophy as a major contributor to heart failure is characterized by complicated mechanisms. Fumarate hydratase (FH) is a crucial enzyme in the tricarboxylic acid cycle. FH mutations and dysfunction have been implicated in various pathological processes including hereditary leiomyomatosis and renal cell cancer, neurodegenerative diseases, metabolic syndrome and cardiovascular diseases. In this study we investigated the role of FH in cardiac hypertrophy. Cardiac hypertrophy was induced in mice by transverse aortic constriction (TAC) surgery as well as in neonatal rat cardiomyocytes (NRCMs) by phenylephrine (PE) stimulation. We showed that the expression levels of FH were gradually increased with development of cardiac hypertrophy in TAC mice. Cardiomyocyte-specific overexpression of FH by intravenous injection of recombinant adeno-associated virus serotype 9 (AAV9) carrying FH two weeks before TAC surgery prevented the morphological changes, cardiac dysfunction and remodeling in TAC mice; FH overexpression also significantly attenuated PE-induced hypertrophy in NRCMs along with suppressed expression of hypertrophic markers ANP, BNP and β-MHC. We demonstrated that FH overexpression alleviated TAC-induced mitochondrial structural damage in cardiomyocytes and facilitated metabolic remodeling. RNA sequencing and untargeted metabolomics revealed that FH overexpression mitigated myocardial remodeling and mitochondrial metabolism dysfunction in TAC mice mainly by suppressing the transcription factor SREBP and reducing the gene expression of elongation of very long chain fatty acids protein 7 (Elovl7). Overexpression of Elovl7 reversed the protective effects of FH in both TAC mice and PE-stimulated NRCMs. Knockdown of the transcription factor SREBP reduced Elovl7 expression, thereby exerting cardioprotective effects. In conclusion, we demonstrate that FH overexpression prevents cardiac hypertrophy in mice by regulating glucose and lipid metabolism through the malate-SREBP-Elovl7 pathway.

Doxorubicin (DOX), a widely used anthracycline in cancer therapy, is associated with significant cardiovascular toxicity. While its cardiotoxic effects are well documented, the mechanisms and prevention of DOX-induced vascular toxicity remain insufficiently explored. Angiotensin-converting enzyme inhibitors (ACEIs), such as perindopril (PER), are commonly used in cardiovascular disease management and may offer vascular protection during chemotherapy. Female ovariectomized Wistar rats were treated with i.v. DOX and/or p.o. PER over five weeks. Cardiac and vascular function were assessed using high-frequency ultrasound and ECG. Vascular reactivity was evaluated in isolated aortal rings using phenylephrine (PE), acetylcholine (ACh), L-N-Nitro arginine methyl ester hydrochloride (L-NAME), and verapamil (VER). Oxidative stress was assessed via plasma 4-hydroxy-2-nonenal (4-HNE) levels, and structural changes were monitored through intima-media thickness (IMT) measurements. DOX administration significantly impaired vascular reactivity, as evidenced by increased contractile responses to PE and reduced endothelium-dependent relaxation. These functional alterations were accompanied by elevated plasma 4-HNE levels, indicating enhanced oxidative stress. Co-treatment with PER preserved vascular responsiveness, reduced contractile tension, and significantly lowered 4-HNE concentrations. Structurally, IMT increased in control and PER-only groups, likely due to post-ovariectomy remodelling, while DOX-treated groups showed no IMT progression. PER co-treatment appeared to stabilize IMT values. PER mitigates DOX-induced vascular toxicity, likely through endothelial protection and reduction of oxidative stress. These findings support the potential use of ACEIs as prophylactic agents in patients undergoing anthracycline-based chemotherapy and highlight the need for further translational studies in cardio-oncology.

Histamine signalling is critical in heart failure (HF). Histamine N-methyltransferase (HNMT) serves as the primary enzyme responsible for histamine clearance in heart, but its role in HF remains undefined. This study investigates HNMT-mediated metabolic-epigenetic crosstalk in HF and evaluates therapeutic strategies targeting this axis. Cardiomyocyte-specific Hnmt-knockout and Hnmt-overexpression mice were generated. Transverse aortic constriction (TAC) was applied to induce HF in mice. RNA sequencing and targeted metabolomics were employed to explore mechanisms underlying the pathological role of HNMT. Urinary N-methylhistamine levels were measured in a cohort of 53 HF and 55 control individuals. HNMT was up-regulated in cardiac tissues from HF patients, TAC-operated mice, and phenylephrine (PE)-treated neonatal mouse cardiomyocytes (NMCMs). Urinary N-methylhistamine levels were elevated in HF patients and positively correlated with severity of HF. In mice, cardiomyocyte-specific Hnmt deletion mitigated hypertrophy and HF induced by TAC or angiotensin II. Pharmacological HNMT inhibition with amodiaquine ameliorated TAC-induced cardiac dysfunction. Conversely, Hnmt overexpression impaired cardiac function. Mechanistically, HNMT reduced intracellular S-adenosylmethionine (SAM) and impaired enhancer of zeste homologue 2 (EZH2) function, decreasing histone 3 lysine 27 trimethylation (H3K27me3) modification at the frizzled-2 (Fzd2) promoter. FZD2 up-regulation activated the WNT/calcium/calmodulin-dependent protein kinase II (CaMKII) pathway, promoting HF. HNMT exacerbates pathological hypertrophy and HF through SAM/FZD2/CaMKII axis. Amodiaquine, the inhibitor of HNMT, shows therapeutic potential against HF. Urinary N-methylhistamine emerges as a non-invasive HF biomarker.

The interplay between opioid analgesics and sepsis in intensive care units (ICUs) is multifaceted, often amplifying immune dysregulation and adversely affecting cardiovascular outcomes. We investigated whether morphine, the prototypical opioid, influences sepsis-induced impairment of arterial baroreceptor function and the accompanying inflammation. Rats were implanted with indwelling catheters in femoral vessels and intracisternal (i.c.) space, and sepsis was induced using the cecal ligation and puncture (CLP) technique. The baroreceptor-mediated control of chronotropic activity was assessed 24h later in awake rats using the vasoactive method, which relates blood pressure changes caused by i.v. phenylephrine (PE) or sodium nitroprusside (SNP) to respective reciprocal changes in heart rate. The treatment of sham rats with morphine or induction of sepsis led to comparable attenuations of reflex decrements and increments in chronotropic responses and decreases in slopes of baroreflex curves (baroreflex sensitivity, BRS). The treatment of septic rats with morphine further amplified the decline in reflex bradycardic (BRSPE), but not tachycardic (BRSSNP), and this exaggerated bradycardia disappeared after (i) systemic blockade of opioid receptors by i.v. morphine or (ii) selective central inhibition of PI3K, MAPK-ERK, MAPK-JNK, NADPHox), or Rho-kinase (ROCK). These pharmacological interventions also attenuated the elevated protein expression of toll-like receptor 4 (TLR4) and monocyte chemoattractant protein-1 (MCP1) in the brainstem nucleus tractus solitarius (NTS) of morphine-treated CLP rats. Overall, morphine augments the sepsis-induced depression of reflex cardiovagal activity through an opioid receptor sensitive mechanism that engages brainstem inflammatory and chemotactic circuits related to PI3K/MAPK/NADPHox/ROCK signaling.

Cardiac hypertrophy is an important risk factor for heart failure and is often accompanied by contractile dysfunction. While hypertrophic growth contributes to disease progression, the underlying molecular mechanisms remain incompletely understood. A proposed contributor is a metabolic shift toward glucose uptake, suggesting that kinases regulating this process, such as protein kinase D1 (PKD1) and downstream target phosphatidylinositol 4-kinase IIIβ (PI4KIIIβ), might be effective targets to mitigate cardiac hypertrophy-induced contractile dysfunction. We investigated whether PI4KIIIβ inhibition downregulates enhanced glucose uptake in hypertrophic cardiomyocytes and thereby treats cardiac hypertrophy-induced contractile dysfunction. Hypertrophy was induced in cultured adult rat cardiomyocytes and human stem cell-derived cardiomyocytes using either phenylephrine (PE) or adenoviral PKD1 overexpression. PE-induced hypertrophy was associated with increased mRNA expression of BNP, activation of hypertrophic signaling, morphological alterations, enhanced protein synthesis and glucose uptake, and impaired contractile function. Treatment with the PI4KIIIβ inhibitor MI14 prevented and reversed PE-stimulated glucose uptake and contractile dysfunction, while hypertrophic signaling, cell size, and protein synthesis remained unaffected. Similar effects on glucose uptake were observed in the PKD1 overexpression model. These findings suggest that targeting myocardial substrate metabolism via the PI4KIIIβ pathway, rather than hypertrophic growth itself, could be a promising strategy to treat hypertrophy-induced contractile dysfunction.

BackgroundProphylaxis of norepinephrine (NE) at a constant rate has been demonstrated to be as efficacious as prophylaxis of phenylephrine (PE) at equivalent doses for the prevention of maternal hypotension during cesarean section. Nevertheless, the impact of prophylactic infusion of NE or PE at a constant rate on pregnant women on fetal outcomes remains to be elucidated.Methods90 women scheduled for caesarean section under spinal or combined spinal–epidural anesthesia were randomly assigned to either the NE or PE group. The “study drug” (NE or PE) was administered intravenously at a rate of 15 mL/h from the time of injection of subarachnoid solution until the time of delivery of the fetus. Fetal umbilical artery (UA) blood was collected for blood gas analysis. The primary outcome of the study was base excess, and the incidence of fetal acidosis (Defined as base excess < 6 mmol/l) and blood glucose levels were also assessed.ResultsThe UA base excess mean (standard deviation) was not different from the NE group, − 1.6 (2.6) versus − 2.4 (2.9) in the PE group (P = 0.223). The incidence of fetal acidosis was 4.7% (NE) versus 14.3% (PE), with no statistically significant difference (P = 0.308). However, fetal blood glucose levels were significantly lower in the NE group, 3.16 (0.43) versus 3.43 (0.60) in the PE group (P = 0.019).ConclusionsProphylactic infusion of equivalent doses of NE at a constant rate resulted in fetal base excess values and an incidence of acidosis comparable to that of PE. However, a lower fetal UA blood glucose value was observed in the NE group, a finding that warrants further investigation.

Sigma receptor agonists are suspected to modulate blood pressure in humans. We investigated how modulation of sigma receptors impacts phenylephrine (PE)-induced contraction in human mesenteric arterial rings obtained from human organ donors. This study also explored the relationship between sigma receptor activation, PE-induced arterial contraction, and the history of the organ donor's alcohol use. The concentration responsiveness of PE-induced arterial contraction was tested using wire myography in the absence and presence of the sigma receptor agonist PRE-084, and the sigma receptor antagonists BD-1047 and SM-21. Sigma receptor-1 expression in the arteries was also investigated using an automated capillary electrophoresis system. The results show that PRE-084 elicited a downward shift in the PE concentration-response curve. Notably, this trend only occurred in arteries from donors with histories of non-/light drinking or moderate drinking (P < 0.05) but not with arteries obtained from donors with histories of heavy or binge drinking. The sigma receptor-1 antagonist BD-1047 elicited an upward shift in the PE concentration-response curve in arteries from non-/light and moderate drinkers but not from heavy drinkers. Interestingly, the sigma receptor-2 antagonist caused an upward shift in the PE concentration-response curve in arteries from all three groups of donors. Notably, sigma receptor-1 protein levels were decreased in arteries from heavy drinkers compared with the other groups. Collectively, the findings suggest that sigma receptors in human arteries may promote relaxation. However, heavy alcohol consumption reduces arterial sigma receptor-1 expression and impairs its ability to modulate contraction.NEW & NOTEWORTHY Activation or inhibition of sigma receptor-1 was found to modulate phenylephrine-induced contraction of isolated mesenteric arteries from human organ donors. However, this effect was impaired in arteries from donors who were heavy alcohol consumers, because the arteries from these individuals had relatively low protein expression of sigma receptor-1. These findings reveal a potential new role of sigma receptor-1 in the control of arterial tone in humans that is modulated by alcohol use.

BackgroundHeart failure (HF) after myocardial infarction (MI) is a serious health issue. This study investigates the therapeutic effects of Shen-Yuan-Dan Capsule (SYD) on post-MI HF and explores its mechanisms, particularly involving m6A modification and autophagy.MethodsNetwork pharmacology and MeRIP-seq were used to predict potential targets. A murine model of post-MI HF was established by ligating the left anterior descending artery in C57BL/6J mice, which were treated with SYD for 6 weeks. Cardiac function, autophagy-related proteins, m6A methylation, and METTL3 levels were assessed. In vitro, H9c2 cardiomyocytes were treated with Phenylephrine (PE) and SYD for 24 h, and hypertrophic biomarkers, autophagy proteins, and m6A methylation were measured. METTL3-overexpressing H9c2 cells were also used to investigate SYD’s effects on gene expression.ResultsIn vivo, SYD treatment significantly improved cardiac function in MI mice, including reduced cardiac hypertrophy, enhanced ejection fraction and fractional shortening, and alleviated myocardial damage, fibrosis, and HF biomarkers. In vitro, SYD inhibited PE-induced hypertrophy in H9c2 cells, including a reduction in cell surface area and a decrease in hypertrophic biomarker levels. SYD also inhibited m6A methylation and METTL3 expression. In both MI mice and PE-treated H9c2 cells, SYD lowered m6A levels and METTL3 expression. Bioinformatics analysis identified autophagy-related signaling pathways. Electron microscopy and autophagy marker detection in myocardial tissue and H9c2 cells showed that SYD restored autophagy levels by regulating the mTOR/TFEB autophagy pathway. In METTL3-overexpressing H9c2 cells, SYD treatment reversed the hypertrophy induced by METTL3 overexpression.ConclusionSYD alleviates post-MI HF by regulating the mTOR/TFEB autophagy pathway through inhibition of METTL3-mediated m6A modification.

Cardiac remodeling, including hypertrophy, is associated with alterations in cytosolic Ca2+ homeostasis of cardiac myocytes that spill over into the nucleoplasm. To test whether nuclear Ca2+ signaling acts causally on the development of cardiac hypertrophy, we expressed parvalbumin to buffer nuclear Ca2+ and we blocked nuclear Ca2+-calmodulin signaling by Adeno-associated virus (AAV)-mediated expression of the calmodulin (CaM) binding-peptide nlsCaMBP4, respectively, in the nuclei of ES cell-derived (Cor.At) and neonatal rat ventricular cardiac myocytes (NRVCM). Expression of nlsCaMBP4, but not parvalbumin, leads to a significant reduction of hypertrophic growth induced by phenylephrine (PE). Expression of nlsCaMBP4 did not alter the amplitude of electrically-evoked intracellular Ca2+ transients in NRVCMs in the absence or presence of PE, and did not affect the PE-evoked increase in store-operated Ca2+ entry. Transcriptome analysis on NRVCMs expressing nlsCaMBP4 revealed that induction of classical hypertrophy markers such as ANF and BNP or MEF2 target genes (such as Srpk3, Xirp1 and Xirp2) were not reduced by nlsCaMBP4 expression. Further analysis of the nuclear Ca2+-calmodulin-regulated gene pool revealed differential expression of genes involved in mRNA translation, including the translation initiation factor subunits Eif2s1, Eif3d and Eif5, whose upregulation was absent in nlsCaMBP4-treated myocytes. Puromycin assays showed that inhibition of Ca2+-calmodulin signaling prevented catecholamine-evoked protein translation, suggesting that Ca2+-calmodulin signaling in the nucleus of cardiac myocytes regulates translation via transcriptional control mechanisms. However, future studies are needed to identify the exact molecular components and machinery that integrate Ca2+-calmodulin-dependent regulation of transcription, protein translation, and development of cardiac myocyte hypertrophy.

Pathological cardiac hypertrophy is a major risk factor for myocardial ischemia, heart failure, and sudden cardiac death, yet its underlying mechanisms remain incompletely understood. Here, we identify Tripartite Motif Containing 21 (TRIM21) as a novel driver of pathological cardiac hypertrophy. TRIM21 was significantly upregulated in mouse hearts following transverse aortic constriction (TAC) and in neonatal rat cardiomyocytes stimulated with phenylephrine (PE). Invitro, TRIM21 knockdown attenuated PE-induced cardiomyocyte hypertrophy, whereas TRIM21 overexpression exacerbated this effect. Consistently, invivo studies revealed that cardiomyocyte-specific TRIM21 overexpression in mice aggravated TAC-induced pathological cardiac hypertrophy. Mechanistically, TRIM21 directly interacted with and promoted K63-linked polyubiquitination of apoptosis signal-regulating kinase 1 (ASK1) at lysine 1064, leading to its enhanced phosphorylation and the subsequent activation of downstream c-Jun N-terminal kinase (JNK)/p38 mitogen-activated protein kinase (MAPK) pathways signaling. Crucially, the pro-hypertrophic effects of TRIM21 were abrogated by pharmacological inhibition of ASK1 (GS-4997). In conclusion, these findings define a novel TRIM21-ASK1 axis that drives pathological cardiac hypertrophy, highlighting TRIM21 as a promising therapeutic target for hypertrophic heart disease and heart failure.

Abstract Introduction While obesity is a recognized contributor to erectile dysfunction (ED), the impact of early-life obesity on the long-term function of the corpus cavernosum (CC) and pudendal artery (PA) is not well defined. We hypothesized that nutritional overload in early development triggers cellular senescence and structural changes, impairing neurovascular components of erectile function in adulthood. Objective We hypothesized that nutritional overload in early development triggers cellular senescence and structural changes, impairing neurovascular components of erectile function in adulthood. To determine whether early-life overnutrition induces long-term structural and functional alterations in the corpus cavernosum and pudendal artery. We aimed to assess cavernous and vascular reactivity, along with molecular markers of senescence and tissue remodeling, using a rat model of postnatal nutritional overload. Methods Wistar rats were nursed in small litter (SL; 3 pups/dam) to induce postnatal overnutrition or in normal litter (NL; 10 pups/dam) as controls. After weaning on postnatal day (PND) 21, animals were maintained on standard chow until PND160. Body weight, fat pad mass, and systolic blood pressure (SBP) were recorded. Functional assays in CC and PA evaluated responses to phenylephrine (PE), acetylcholine (ACh), and electrical field stimulation (EFS). Transcriptomic profiling by RNA sequencing and gene validation via RT-qPCR were conducted to investigate markers of senescence and tissue remodeling. Results Final body mass did not differ between groups, but SL rats exhibited higher retroperitoneal and perigonadal fat mass, along with elevated SBP (SL: 120.5 ± 1.2 mmHg vs NL: 114.9 ± 0.58 mmHg). In the CC, EFS-induced relaxation was reduced in SL animals (16 Hz: SL 2.39 ± 0.53 mN vs NL 3.06 ± 0.28 mN), while PE- and EFS-induced contractions were increased and partially reversed by indomethacin, suggesting prostanoid involvement. In the PA, ACh-mediated relaxation was significantly impaired (Emax: SL 28 ± 6% vs NL 68 ± 5.5%), without changes in PE-induced tone. Transcriptomic analysis revealed 124 differentially expressed genes (DEGs) in the CC, 99 in male PA, and 252 in female PA. Enrichment mapping in male tissues highlighted pathways involved in extracellular matrix remodeling, metabolic control, and secretin-related GPCR signaling (e.g., Col1a1, Fstl3, Adamts6, Thbs6, PI3K-Akt-mTOR). In contrast, DEGs in female PA were enriched for innate immune and metabolic/hormonal response pathways. RT-qPCR in CC confirmed increased Bgn and Col1a2, along with altered expression of Calcrl, Vipr2, and Glp1/2r, consistent with senescence-associated remodeling. Cross-tissue comparison identified 11 shared genes, possibly involved in neurovascular tone, metabolic stress responses, and architectural remodeling. Conclusions Early-life obesity induces persistent structural and functional alterations in erectile and pudendal tissues, likely contributing to erectile dysfunction in adulthood. These changes appear to be mediated by pathways involving senescence, fibrosis, and secretin GPCR signaling. Additionally, the identification of shared molecular signatures across tissues highlights a potential neurovascular-metabolic axis disrupted by early metabolic stress. Ongoing studies aim to elucidate the specific roles of these candidate genes and pathways in the pathophysiology of obesity-induced sexual dysfunction. Disclosure No