Search Results (87)

Right heart failure (RHF) is a major cause of morbidity and mortality, often resulting from pulmonary arterial hypertension and characterized by impaired calcium (Ca²⁺) handling and maladaptive remodeling. Phosphodiesterase 9A (PDE9A), a cGMP-specific phosphodiesterase, has been proposed as a potential contributor to RHF pathogenesis by suppressing the cardioprotective cGMP–PKG signaling pathway—a conclusion largely extrapolated from left-sided heart failure models. This review examines existing evidence regarding PDE9A’s role in RHF, focusing on its effects on intracellular calcium cycling, fibrosis, hypertrophy, and contractile dysfunction. Data from preclinical models demonstrate that pathological stress upregulates PDE9A expression in cardiomyocytes, leading to diminished PKG activation, impaired SERCA2a function, RyR2 instability, and increased arrhythmogenic Ca²⁺ leak. Pharmacological or genetic inhibition of PDE9A restores cGMP signaling, improves calcium handling, attenuates hypertrophic and fibrotic remodeling, and enhances ventricular compliance. Early-phase clinical studies in heart failure populations suggest that PDE9A inhibitors are well tolerated and effectively augment cGMP levels, although dedicated trials in RHF are still needed. Overall, these findings indicate that targeting PDE9A may represent a promising therapeutic strategy to improve outcomes in RHF by directly addressing the molecular mechanisms underlying calcium mishandling and myocardial remodeling. Full article

Background/Objectives: Fructose-1,6-bisphosphate (FBP) is an intermediate product of the glycolytic pathway with analgesic effect in acute inflammatory pain model via the production of adenosine. However, whether FBP is active in neuropathic pain is unknown. Therefore, we reason that it would be suitable to investigate the analgesic effect and mechanism of action of FBP in a model of chronic constriction injury (CCI) of sciatic nerve-induced neuropathic pain in mice. Methods: After CCI induction, mice received FBP, adenosine, A1 and/or A2A receptor antagonists, and/or inhibitors of the nitric oxide (NO)/cyclic guanosine monophosphate (cGMP)/protein kinase G (PKG)/ATP sensitive K channels (KATP) signaling pathway. Results: FBP (up to 85%) and adenosine (up to 84%) inhibited the mechanical hyperalgesia (electronic aesthesiometer) induced by CCI with similar profiles. FBP analgesia was dependent on adenosine because adenosine A1 and A2A receptors antagonists diminished FPB activity (100% and 79%, respectively). FBP analgesia was also dependent on activating the NO/cGMP/PKG/KATP signaling pathway. Furthermore, FBP treatment increased the production of NO in cultured dorsal root ganglia (DRG) neurons (100% increase), whereas neuronal nitric oxide synthase (nNOS) inhibition decreased (up to 70%) the analgesic effect of FBP. We also observed that FBP reduced the calcium levels of transient receptor potential ankyrin 1 (TRPA1)⁺ DRG neurons (85%) and paw-flinching triggered by TRPA1 activation (38%). Conclusions: FBP reduced neuropathic pain by reducing DRG neuron activation. The mechanisms involved the activation of adenosine A1 and A2A receptors to trigger the analgesic NO/cGMP/PKG/KATP signaling pathway and reducing TRPA1⁺ DRG neuron activity. Full article

Background/Objectives: Pulmonary hypertension is a progressive disease leading to right heart failure. One treatment strategy is to induce vasodilation via the nitric oxide–soluble guanylate cyclase–cyclic guanosine monophosphate (NO–sGC–cGMP) signaling pathway. There are currently two soluble guanylate cyclase stimulators on the market: Riociguat and vericiguat, with vericiguat having a longer half-life and needing to be taken only once a day. This study investigated whether the pharmacological differences between the drugs affect pulmonary vessels and airways. Methods: The effects of vericiguat and riociguat on pulmonary arteries, veins, and airways were studied using rat precision-cut lung slices (PCLS). Vessels were pretreated with endothelin-1 and airways with serotonin. In isolated perfused lungs (IPL), the effects of sGC stimulation on pulmonary artery pressure (PAP), airway resistance, inflammatory cytokine, and chemokine release were quantified. Results: Riociguat and vericiguat caused pulmonary artery dilation in PCLS. During IPL, riociguat was more effective than vericiguat in reducing PAP with a statistically significant reduction of 10%. Both drugs were potent bronchodilators in preconstricted airways (p < 0.001). Only vericiguat reduced airway resistance during IPL, as shown here for the first time. Both drugs significantly reduced IL-6 and IL-1ß levels, while riociguat also reduced VEGF-A and KC-GRO levels. Conclusions: Riociguat and vericiguat had three main effects in the two rat ex-vivo models: They dilated the pulmonary arteries, induced bronchodilation, and reduced inflammation. These properties could make sGC stimulators useful for treating diseases associated with endothelial dysfunction. In the future, vericiguat may provide an alternative treatment to induce bronchodilation in respiratory diseases. Full article

Background/Objectives Studies in rodents indicate that disruptions in both cyclic adenosine monophosphate (cAMP) and cyclic guanosine monophosphate (cGMP) signaling pathways are involved in the development of hyperactive behavior. We examined whether vinpocetine, a phosphodiesterase type 1 inhibitor that enhances brain cAMP and cGMP levels, could mitigate locomotor hyperactivity in mice exposed to lead during early development. Methods Swiss mice were exposed to 90 ppm of lead in their drinking water throughout gestation and the first ten postnatal days. At postnatal day 10 (PN10), blood lead levels (BLLs) were about 30 µg/dL. At PN30, animals either received vinpocetine (20 mg/kg, i.p.) or a vehicle 4 h before the evaluation of locomotor activity in the open field. Results Lead-exposed males did not display differences in locomotor activity compared to controls, while lead-exposed females showed a significant increase in locomotion. Vinpocetine treatment significantly reversed the lead-induced hyperactivity in females. Conclusions These findings suggest that the cAMP and cGMP signaling pathways play a role in the hyperactivity induced by lead exposure. Full article

Phosphodiesterase (PDE) enzymes regulate intracellular signaling pathways crucial for brain development and the pathophysiology of neurological disorders. Among the 11 PDE subtypes, PDE4 and PDE5 are particularly significant due to their regulation of cyclic adenosine monophosphate (cAMP) and cyclic guanosine monophosphate (cGMP) signaling, respectively, which are vital for learning, memory, and neuroprotection. This review synthesizes current evidence on the roles of PDE4 and PDE5 in neurological health and disease, focusing on their regulation of second messenger pathways and their implications for brain function. Elevated PDE4 activity impairs synaptic plasticity by reducing cAMP levels and protein kinase A (PKA) activity, contributing to cognitive decline, acute brain injuries, and neuropsychiatric conditions such as bipolar disorder and schizophrenia. Similarly, PDE5 dysregulation disrupts nitric oxide (NO) signaling and protein kinase G (PKG) pathways, which are involved in cerebrovascular homeostasis, recovery after ischemic events, and neurodegenerative processes in Alzheimer’s, Parkinson’s, and Huntington’s diseases. PDE4 and PDE5 are promising therapeutic targets for neurological disorders. Pharmacological modulation of these enzymes offers potential to enhance cognitive function and mitigate pathological mechanisms underlying brain injuries, neurodegenerative diseases, and psychiatric disorders. Further research into the regulation of PDE4 and PDE5 will advance therapeutic strategies for these conditions. Full article

Vascular smooth muscle cell (SMC) relaxation by guanylyl cyclases (GCs) and cGMP is mediated by NO and its receptor soluble GC (sGC) or natriuretic peptides (NPs) ANP/BNP and CNP with the receptors GC-A and GC-B, respectively. It is commonly accepted that cultured SMCs differ from those in intact vessels. Nevertheless, cell culture often remains the first step for signaling investigations and drug testing. Previously, we showed that even popular reference genes changed dramatically after SMC isolation from aorta. Regarding NP receptors, a substantial amount of data relies on cell culture. We hypothesize that the NP/cGMP system in intact aortic tunica media differs from isolated and cultured aortic SMCs. Therefore, we studied isolation and culturing effects on the expression of NP receptors GC-A, GC-B, and NP clearance receptor (NPRC) compared to sGC. We investigated intact tunica media and primary SMCs from the longitudinal halves of the same rat aorta. GC activity was monitored by cyclic guanosine monophosphate (cGMP). In addition, we hypothesize that there are sex-dependent differences in the NP/cGMP cascade in both intact tissue and cultured cells. We, therefore, analyzed a male and female cohort. Expression was quantified by RT-qPCR comparing aortic media and SMCs with our recently validated reference gene (RG) small nuclear ribonucleoprotein 2 (U2). Only GC-A was stably expressed. In intact media, GC-A exceeded GC-B and NPRC. However, GC-B, NPRC, and sGC were dramatically upregulated in cultured SMCs of the same aortae different from the stable GC-A. The expression was mirrored by NP-induced GC activity. In cultured cells, changes in GC activity were delayed compared to receptor expression. Minor differences between both sexes could also be revealed. Thus, isolation and culture fundamentally alter the cGMP system in vascular SMCs with potential impact on drug testing and scRNAseq. Especially, the dramatic increase in the clearance receptor NPRC in culture might distort all physiological ANP, BNP, and CNP effects. Full article

African swine fever (ASF), a highly infectious and devastating disease affecting both domestic pigs and wild boars, is caused by the African swine fever virus (ASFV). ASF has resulted in rapid global spread of the disease, leading to significant economic losses within the swine industry. A significant obstacle to the creation of safe and effective ASF vaccines is the existing knowledge gap regarding the pathogenesis of ASFV and its mechanisms of immune evasion. The cyclic GMP–AMP synthase (cGAS)–stimulator of interferon genes (STING) pathway is a major pathway mediating type I interferon (IFN) antiviral immune response against infections by diverse classes of pathogens that contain DNA or generate DNA in their life cycles. To evade the host’s innate immune response, ASFV encodes many proteins that inhibit the production of type I IFN by antagonizing the cGAS-STING signaling pathway. Multiple proteins of ASFV are involved in promoting viral replication by protein–protein interaction during ASFV infection. The protein QP383R could impair the function of cGAS. The proteins EP364R, C129R and B175L could disturb the function of cyclic guanosine monophosphate-adenosine monophosphate (cGAMP). The proteins E248R, L83L, MGF505-11L, MGF505-7R, H240R, CD2v, E184L, B175L and p17 could interfere with the function of STING. The proteins MGF360-11L, MGF505-7R, I215L, DP96R, A151R and S273R could affect the function of TANK Binding Kinase 1 (TBK1) and IκB kinase ε (IKKε). The proteins MGF360-14L, M1249L, E120R, S273R, D129L, E301R, DP96R, MGF505-7R and I226R could inhibit the function of Interferon Regulatory Factor 3 (IRF3). The proteins MGF360-12L, MGF505-7R/A528R, UBCv1 and A238L could inhibit the function of nuclear factor kappa B (NF-Κb). Full article

Hydrogen sulfide (H₂S), a gas traditionally considered toxic, is now recognized as a vital endogenous signaling molecule with a complex physiology. This comprehensive study encompasses a systematic literature review that explores the intricate mechanisms underlying H₂S-induced vasodilation. The vasodilatory effects of H₂S are primarily mediated by activating ATP-sensitive potassium (K_ATP) channels, leading to membrane hyperpolarization and subsequent relaxation of vascular smooth muscle cells (VSMCs). Additionally, H₂S inhibits L-type calcium channels, reducing calcium influx and diminishing VSMC contraction. Beyond ion channel modulation, H₂S profoundly impacts cyclic nucleotide signaling pathways. It stimulates soluble guanylyl cyclase (sGC), increasing the production of cyclic guanosine monophosphate (cGMP). Elevated cGMP levels activate protein kinase G (PKG), which phosphorylates downstream targets like vasodilator-stimulated phosphoprotein (VASP) and promotes smooth muscle relaxation. The synergy between H₂S and nitric oxide (NO) signaling further amplifies vasodilation. H₂S enhances NO bioavailability by inhibiting its degradation and stimulating endothelial nitric oxide synthase (eNOS) activity, increasing cGMP levels and potent vasodilatory responses. Protein sulfhydration, a post-translational modification, plays a crucial role in cell signaling. H₂S S-sulfurates oxidized cysteine residues, while polysulfides (H₂Sn) are responsible for S-sulfurating reduced cysteine residues. Sulfhydration of key proteins like K_ATP channels and sGC enhances their activity, contributing to the overall vasodilatory effect. Furthermore, H₂S interaction with endothelium-derived hyperpolarizing factor (EDHF) pathways adds another layer to its vasodilatory mechanism. By enhancing EDHF activity, H₂S facilitates the hyperpolarization and relaxation of VSMCs through gap junctions between endothelial cells and VSMCs. Recent findings suggest that H₂S can also modulate transient receptor potential (TRP) channels, particularly TRPV4 channels, in endothelial cells. Activating these channels by H₂S promotes calcium entry, stimulating the production of vasodilatory agents like NO and prostacyclin, thereby regulating vascular tone. The comprehensive understanding of H₂S-induced vasodilation mechanisms highlights its therapeutic potential. The multifaceted approach of H₂S in modulating vascular tone presents a promising strategy for developing novel treatments for hypertension, ischemic conditions, and other vascular disorders. The interaction of H₂S with ion channels, cyclic nucleotide signaling, NO pathways, ROS (Reactive Oxygen Species) scavenging, protein sulfhydration, and EDHF underscores its complexity and therapeutic relevance. In conclusion, the intricate signaling paradigms of H₂S-induced vasodilation offer valuable insights into its physiological role and therapeutic potential, promising innovative approaches for managing various vascular diseases through the modulation of vascular tone. Full article

With the continuous improvement in living standards, people’s demand for high-quality meat is increasing. Ningxiang pig has delicious meat of high nutritional value, and is loved by consumers. However, its slow growth and low meat yield seriously restrict its efficient utilization. Gene expression is the internal driving force of life activities, so in order to fundamentally improve its growth rate, it is key to explore the molecular mechanism of skeletal muscle development in Ningxiang pigs. In this paper, Ningxiang boars were selected in four growth stages (30 days: weaning period, 90 days: nursing period, 150 days: early fattening period, and 210 days: late fattening period), and the longissimus dorsi (LD) muscle was taken from three boars in each stage. The fatty acid content, amino acid content, muscle fiber diameter density and type of LD were detected by gas chromatography, acidolysis, hematoxylin eosin (HE) staining and immunofluorescence (IF) staining. After transcription sequencing, weighted gene co-expression network analysis (WGCNA) combined with the phenotype of the LD was used to explore the key genes and signaling pathways affecting muscle development. The results showed that 10 modules were identified by WGCNA, including 5 modules related to muscle development stage, module characteristics of muscle fiber density, 5 modules characteristic of muscle fiber diameter, and a module characteristic of palmitoleic acid (C16:1) and linoleic acid (C18:2n6C). Gene ontology (GO) enrichment analysis found that 52 transcripts relating to muscle development were enriched in these modules, including 44 known genes and 8 novel genes. The Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis showed that these genes were enriched in the auxin, estrogen and cyclic guanosine monophosphate-protein kinase G (cGMP-PKG) pathways. Twelve of these genes were transcription factors, there were interactions among 20 genes, and the interactions among 11 proteins in human, pig and mouse were stable. To sum up, through the integrated analysis of phenotype and transcriptome, this paper analyzed the key genes and possible regulatory networks of skeletal muscle development in Ningxiang pigs at various stages, to provide a reference for the in-depth study of skeletal muscle development. Full article

Bacillus velezensis is a promising candidate for biocontrol applications. A common second messenger molecule, bis-(3,5)-cyclic-dimeric-guanosine monophosphate (c-di-GMP), has the ability to regulate a range of physiological functions that impact the effectiveness of biocontrol. However, the status of the c-di-GMP signaling pathway in biocontrol strain LQ-3 remains unknown. Strain LQ-3, which was isolated from wheat rhizosphere soil, has shown effective control of wheat sharp eyespot and has been identified as B. velezensis through whole-genome sequencing analyses. In this study, we investigated the intracellular c-di-GMP signaling pathway of LQ-3 and further performed a comparative genomic analysis of LQ-3 and 29 other B. velezensis strains. The results revealed the presence of four proteins containing the GGDEF domain, which is the conserved domain for c-di-GMP synthesis enzymes. Additionally, two proteins were identified with the EAL domain, which represents the conserved domain for c-di-GMP degradation enzymes. Furthermore, one protein was found to possess a PilZ domain, indicative of the conserved domain for c-di-GMP receptors in LQ-3. These proteins are called DgcK, DgcP, YybT, YdaK, PdeH, YkuI, and DgrA, respectively; they are distributed in a similar manner across the strains and belong to the signal transduction family. We selected five genes from the aforementioned seven genes for further study, excluding YybT and DgrA. They all play a role in regulating the motility, biofilm formation, and colonization of LQ-3. This study reveals the c-di-GMP signaling pathway associated with biocontrol features in B. velezensis LQ-3, providing guidance for the prevention and control of wheat sharp eyespot by LQ-3. Full article

Heart failure (HF) is a syndrome characterized by signs and symptoms resulting from structural or functional cardiac abnormalities, confirmed by elevated natriuretic peptides or evidence of congestion. HF patients are classified according to left ventricular ejection fraction (LVEF). Worsening HF (WHF) is associated with increased short- and long-term mortality, re-hospitalization, and healthcare costs. The standard treatment of HF includes angiotensin-converting enzyme inhibitors, angiotensin receptor–neprilysin inhibitors, mineralocorticoid-receptor antagonists, beta-blockers, and sodium-glucose-co-transporter 2 inhibitors. To manage systolic HF by reducing mortality and hospitalizations in patients experiencing WHF, treatment with vericiguat, a direct stimulator of soluble guanylate cyclase (sGC), is indicated. This drug acts by stimulating sGC enzymes, part of the nitric oxide (NO)–sGC–cyclic guanosine monophosphate (cGMP) signaling pathway, regulating the cardiovascular system by catalyzing cGMP synthesis in response to NO. cGMP acts as a second messenger, triggering various cellular effects. Deficiencies in cGMP production, often due to low NO availability, are implicated in cardiovascular diseases. Vericiguat stimulates sGC directly, bypassing the need for a functional NO-sGC-cGMP axis, thus preventing myocardial and vascular dysfunction associated with decreased sGC activity in heart failure. Approved by the FDA in 2021, vericiguat administration should be considered, in addition to the four pillars of reduced EF (HFrEF) therapy, in symptomatic patients with LVEF < 45% following a worsening event. Cardiac rehabilitation represents an ideal setting where there is more time to implement therapy with vericiguat and incorporate a greater number of medications for the management of these patients. This review covers vericiguat’s metabolism, molecular mechanisms, and drug–drug interactions. Full article

This study aimed to evaluate the effects of arginine (0.5%, 1%, 1.5%, 2%, and 2.5% arginine supplementation levels were selected) on the ovarian development of Pacific white shrimp (Litopenaeus vannamei). The analyzed arginine supplementation levels in each diet were 2.90%, 3.58%, 4.08%, 4.53%, 5.04%, and 5.55%, respectively. A total of 540 shrimp (an initial weight of approximately 14 g) with good vitality were randomly distributed into six treatments, each of which had three tanks (300 L in volume filled with 200 L of water), with 30 shrimp per duplicate. Shrimp were fed three times a day (6:00 a.m., 11:00 a.m., and 6:00 p.m.). The results showed that after the 12-week raring cycle, shrimp fed with 4.08% and 4.53% Arg achieved better ovary development, which was identified by ovarian stage statistics, ovarian morphology observation, serum hormone levels (methylfarneside (MF); 5-hydroxytryptamine (5-HT); estradiol (E2); and gonadotropin-releasing hormone (GnRH)), gene expression (DNA meiotic recombinase 1 (dmc1), proliferating cell nuclear antigen (pcna), drosophila steroid hormone 1 (cyp18a), retinoid X receptor (rxra), and ecdysone receptor (ecr)). Further in-depth analysis showed that 4.08% and 4.53% Arg supplementation increased the concentration of vitellogenin in hepatopancreas and serum (p < 0.05) and upregulated the expression level of hepatopancreatic vg and vgr (p < 0.05), which promoted the synthesis of hepatopancreas exogenous vitellogenin and then transported it into the ovary through the vitellogenin receptor and further promoted ovarian maturation in L. vannamei. Meanwhile, compared with the control group, the expression level of vg in the ovary of the 4.53% Arg group was significantly upregulated (p < 0.05), which indicated endogenous vitellogenin synthesis in ovarian maturation in L. vannamei. Moreover, the expression of genes related to the mechanistic target of the rapamycin complex 1 (mTORC1) pathway and protein levels was regulated by dietary arginine supplementation levels. Arginine metabolism-related products, including nitric oxide synthase (NOS), nitric oxide (NO), and cyclic guanosine monophosphate (cGMP), were also affected. RNA interference was applied here to study the molecular regulation mechanism of arginine on ovarian development in L. vannamei. A green fluorescent protein (GFP)-derived double-stranded RNA (dsGFP) is currently commonly used as a control, while TOR-derived dsRNA (dsTOR) and NOS-derived dsRNA (dsNOS) were designed to build the TOR and NOS in vivo knockdown model. The results showed that the mTORC1 and NO-sGC-cGMP pathways were inhibited, while the vitellogenin receptor and vitellogenin gene expression levels were downregulated significantly in the hepatopancreas and ovary. Overall, dietary arginine supplementation could enhance endogenous and exogenous vitellogenin synthesis to promote ovary development in L. vannamei, and the appropriate dosages were 4.08% and 4.53%. The NO-sGC-cGMP and mTORC1 signaling pathways mediated arginine in the regulation of ovary development in L. vannamei. Full article

Hypertensive disorders in pregnancy (HDP) are the most prevalent diseases during pregnancy. In addition to the already identified risk factors, exposure to environmental contaminants has been also considered a new one. Phthalates, which are classified as priority environmental pollutants due to their ubiquitousness and endocrine disrupting properties, have been implicated in HDP in some epidemiological studies. Nevertheless, phthalates’ vascular impacts still need to be clarified. Thus, we aimed to understand the connection between phthalates exposure and the occurrence of gestational hypertension, as well as the pathway involved in the pathological vascular effects. We investigated diethyl phthalate’s (DEP) effect on the vascular reactivity of the human umbilical arteries (HUAs) from normotensive and hypertensive pregnant women. Both DEP’s nongenomic (within minutes effect) and genomic (24 h exposure to DEP) actions were evaluated, as well as the contribution of cyclic guanosine monophosphate and Ca²⁺ channel pathways. The results show that short-term exposure to DEP interferes with serotonin and histamine receptors, while after prolonged exposure, DEP seems to share the same vasorelaxant mechanism as estrogens, through the NO/sGC/cGMP/PKG signaling pathway, and to interfere with the L-type Ca²⁺ channels. Thus, the vascular effect induced by DEP is similar to that observed in HUA from hypertensive pregnancies, demonstrating that the development of HDP may be a consequence of DEP exposure. Full article

Previous studies have reported the therapeutic effects of oleuropein (OP) consumption on the early stage of diabetic nephropathy and diabetic cardiomyopathy. However, the efficacy of OP on the long-course of these diabetes complications has not been investigated. Therefore, in this study, to investigate the relieving effects of OP intake on these diseases, and to explore the underlying mechanisms, db/db mice (17-week-old) were orally administrated with OP (200 mg/kg bodyweight) for 15 weeks. We found that OP reduced expansion of the glomerular mesangial matrix, renal inflammation, renal fibrosis, and renal apoptosis. Meanwhile, OP treatment exerted cardiac anti-fibrotic, anti-inflammatory, and anti-apoptosis effects. Notably, transcriptomic and bioinformatic analyses indicated 290 and 267 differentially expressed genes in the kidney and heart replying to OP treatment, respectively. For long-course diabetic nephropathy, OP supplementation significantly upregulated the cyclic guanosine monophosphate-dependent protein kinase (cGMP–PKG) signaling pathway. For long-course diabetic cardiomyopathy, p53 and cellular senescence signaling pathways were significantly downregulated in response to OP supplementation. Furthermore, OP treatment could significantly upregulate the transcriptional expression of the ATPase Na⁺/K⁺ transporting subunit alpha 3, which was enriched in the cGMP–PKG signaling pathway. In contrast, OP treatment could significantly downregulate the transcriptional expressions of cyclin-dependent kinase 1, G two S phase expressed protein 1, and cyclin B2, which were enriched in p53 and cellular senescence signal pathways; these genes were confirmed by qPCR validation. Overall, our findings demonstrate that OP ameliorated long-course diabetic nephropathy and cardiomyopathy in db/db mice and highlight the potential benefits of OP as a functional dietary supplement in diabetes complications treatment. Full article

Diallyl disulfide (DADS) is a well-known principal functional component derived from garlic (Allium sativum) that has various health benefits. Previously, we identified a 67-kDa laminin receptor, a receptor for oolong tea polyphenol oolonghomobisflavan B (OHBFB). However, its molecular mechanisms still remain to be elucidated. Here, we show that DADS synergistically enhanced the effect of the oolong tea polyphenol oolonghomobisflavan B (OHBFB), which induces apoptosis in acute myeloid leukemia (AML) cancer cells without affecting normal human peripheral blood mononuclear cells (PBMCs). The underlying mechanism of OHBFB-induced anti-AML effects involves the upregulation of the 67-kDa laminin receptor/endothelial nitric oxide synthase/cyclic guanosine monophosphate (cGMP)/protein kinase c delta (PKCδ)/acid sphingomyelinase (ASM)/cleaved caspase-3 signaling pathway. In conclusion, we show that the combination of OHBFB and DADS synergistically induced apoptotic cell death in AML cells through activation of 67LR/cGMP/PKCδ/ASM signaling pathway. Moreover, in this mechanism, we demonstrate DADS may reduce the enzyme activity of phosphodiesterase, which is a negative regulator of cGMP that potentiates OHBFB-induced AML apoptotic cell death without affecting normal PBMCs. Full article