Receptor Signaling Research Articles

Exploring diabesity pathophysiology through proteomic analysis using Caenorhabditis elegans.

Diabesity, characterized by obesity-driven Type 2 diabetes mellitus (T2DM), arises from intricate genetic and environmental interplays that induce various metabolic disorders. The systemic lipid and glucose homeostasis is controlled by an intricate cross-talk of internal glucose/insulin and fatty acid molecules to maintain a steady state of internal environment. In this study, Caenorhabditis elegans were maintained to achieve glucose concentrations resembling the hyperglycemic conditions in diabetic patients to delve into the mechanistic foundations of diabesity. Various assays were conducted to measure intracellular triglyceride levels, lifespan, pharyngeal pumping rate, oxidative stress indicators, locomotor behavior, and dopamine signaling. Proteomic analysis was also performed to identify differentially regulated proteins and dysregulated KEGG pathways, and microscopy and immunofluorescence staining were employed to assess collagen production and anatomical integrity. Worms raised on diets high in glucose and cholesterol exhibited notably increased intracellular triglyceride levels, a decrease in both mean and maximum lifespan, and reduced pharyngeal pumping. The diabesity condition induced oxidative stress, evident from heightened ROS levels and distinct FT-IR spectroscopy patterns revealing lipid and protein alterations. Furthermore, impaired dopamine signaling and diminished locomotors behavior in diabesity-afflicted worms correlated with reduced motility. Through proteomic analysis, differentially regulated proteins encompassing dysregulated KEGG pathways included insulin signaling, Alzheimer's disease, and nicotinic acetylcholine receptor signaling pathways were observed. Moreover, diabesity led to decreased collagen production, resulting in anatomical disruptions validated through microscopy and immunofluorescence staining. This underscores the impact of diabesity on cellular components and structural integrity in C. elegans, providing insights into diabesity-associated mechanisms.

Legumain deficiency halts atherogenesis by modulating T cell receptor signaling.

Atherosclerosis is an age-related pathological process associated with elevated levels of legumain in plaques and plasma. However, the underlying mechanisms remain unclear. The aim of this study was to investigate the role of legumain in the progression of atherosclerotic plaques, with a particular focus on functional and phenotypic changes in CD4+ T cells. Apolipoprotein E-deficient (Apoe-/-) mice were crossed with legumain-deficient (Lgmn-/-) mice to generate Lgmn-/-Apoe-/- mice. CD4+ T cells accumulated in the atherosclerotic plaques of Apoe-/- mice fed a high-fat diet. Deletion of legumain attenuated the deposition of CD4+ T cells in plaques and reduced the number of atherosclerotic lesions. The levels of CD4+ T cells in the blood, lymph nodes, and spleen were decreased in Lgmn-/- mice. Transcriptomic analysis revealed that the deletion of legumain decreased the differentiation, survival, and function of CD4+ memory T cells by suppressing the T cell receptor (TCR) signaling pathway. These changes are accompanied by the downregulation of the antiapoptotic protein B-cell lymphoma 2 (Bcl-2) and the reduced release of interleukin (IL)-2 and interferon (IFN)-γ. These results suggest that legumain deficiency may play a role in the development of atherosclerosis by impairing the survival, proliferation, and function of CD4+ T cells. Inhibition of legumain activity may be an innovative therapy for the treatment of atherosclerosis.

Receptor determinants for ß-arrestin functional specificity at C-X-C chemokine receptor 5 (CXCR5).

ß-arrestins are multi-faceted adaptor proteins that mediate G protein-coupled receptor (GPCR) desensitization, internalization, and signaling. It is emerging that receptor-specific determinants specify these divergent functions at GPCRs, yet this remains poorly understood. Here, we set out to identify the receptor determinants responsible for ß-arrestin-mediated regulation of the chemokine receptor CXCR5. Using bioluminescence resonance energy transfer (BRET) we show that ß-arrestin1 and ß-arrestin2 are dose-dependently recruited to CXCR5 by its cognate ligand CXCL13. The carboxy-terminal tail of CXCR5 contains several Ser/Thr residues that can be divided into 3 discrete phospho-site clusters based on their position relative to transmembrane domain 7. Mutagenesis experiments revealed that the distal and medial phospho-site clusters, but not the proximal, are required for agonist-stimulated ß-arrestin1 or ß-arrestin2 recruitment to CXCR5. Consistent with this, we provide evidence that the distal and medial, but not proximal, phospho-site clusters are required for receptor desensitization. Surprisingly, the individual phospho-site clusters are not required for agonist-stimulated internalization of CXCR5. Further, we show that CXCL13-stimulated CXCR5 internalization and ERK1/2 phosphorylation, but not desensitization, remain intact in HEK293 cells lacking ß-arrestin1 and ß-arrestin2. Our study provides evidence that b-arrestins are recruited to CXCR5 and are required for desensitization but are dispensable for internalization or signaling, suggesting that discrete receptor determinants specify the divergent functions of ß-arrestins. Significance Statement CXCL13 and CXCR5 are important in the immune system and are linked to diseases, yet regulation of CXCR5 signaling remains poorly understood. We provide evidence that a phospho-site cluster located at the extreme distal carboxyl-terminal tail of the receptor is responsible for ß-arrestin recruitment and receptor desensitization. ß-arrestins are not required for CXCL13-stimulated internalization or signaling, indicating that ß-arrestins perform only one of their functions at CXCR5 and that discrete receptor determinants specify the divergent functions of ß-arrestins.

Anticancer Potential of Cyanidin and Cyanidin-3-Glucoside Through TrkB Receptor Inhibition: Evidence From Molecular Interaction Docking

Cancer remains a global health problem with persisten demand on therapeutic development to inhibit cancer cells growth without harmful effects on healthy cells. Plant bioactive compounds are intensively studied as anticancer via several signalling pathway. Anticancer therapy via inhibition of tropomyosin kinase receptor-B (TrkB) signal was previously proposed as target therapy. The role of plant metabolites cyanidin and cyanidin-3-glucoside as TrkB inhibitor is has not been investigated. This study was aimed to identify physicochemical of cyanidin and cyanidin- 3-glucoside as well as determine it’s role towards TrkB receptor signalling pathway through in silico approach. Molecular docking was performed using Hex 8.0.0 software and visualizes using Discovery Studio Visualizer. The energy binding of TrkB with cyanidin and cyanidin-3-glucoside was -263,21 kcal/mol and 281,65 kcal/mol respectively. Complex of cyanidin-3-glucoside had hydrogen and hydrophobic bond more than TrkB-cyanidin complex. The hydrogen bond formed at Lys637, Arg558 and Gly 561 amino residues. Physicochemical analysis demonstrated that both ligand are potential as kinase enzyme inhibitor. Cyanidin-3-glucoside was predicted more potential as anticancer than cyanidin via TrkB receptor inhibition. Future studies are required to confirm current finding both in-vitro and in-vivo models.

LncRNA AGAP2-AS1 stabilizes ATG9A to promote autophagy in endothelial cells - Implications for burn wound healing

Deep second- or mixed-degree burn lesions are difficult to heal due to the impaired dermis supporting of epidermis renewal and nutrition delivery. Early dermis debridement and preservation speed healing and enhance results, emphasizing the need of knowing processes that promote burn-denatured dermis recovery, notably endothelial cell angiogenesis and autophagy. Integrative bioinformatics investigations identified AGAP2-AS1 as a highly elevated lncRNA in burn tissues. Pearson's correlation study connected AGAP2-AS1 to 112 differently co-expressed protein-coding genes involved in burn healing processes such cell cycle and TGF-beta receptor signaling. Experimental validation showed that heat damage elevated AGAP2-AS1 in HUVECs and HDMECs. Functionally, AGAP2-AS1 overexpression in heat-denatured HUVECs and HDMECs increased cell survival, migration, invasion, and angiogenesis. In addition, AGAP2-AS1 overexpression increased endothelial cell autophagy. Additional investigation showed AGAP2-AS1's association with ATG9A, stabilizing it. Post-heat damage, ATG9A knockdown drastically reduced HUVEC and HDMEC survival, migration, invasion, angiogenesis, and autophagy. More notably, ATG9A knockdown drastically reduced the benefits of AGAP2-AS1 overexpression on endothelial cell functions and autophagy. The positive association between AGAP2-AS1 and ATG9A expression in burn tissue samples highlights their crucial roles in endothelial cell response to heat injury, indicating that targeting this axis may aid burn wound healing. The research found that lncRNA AGAP2-AS1 stabilizes ATG9A and promotes autophagy in endothelial cells. These results imply that targeting the AGAP2-AS1/ATG9A axis may improve angiogenesis and tissue regeneration in burn injuries, revealing burn wound healing molecular pathways.

Distinct Hippocampal Expression Profiles of lncRNAs in Obese Type 2 Diabetes Mice Exhibiting Cognitive Impairment.

Cognitive dysfunction has been accepted as a possible complication of type 2 diabetes (T2D), but few studies revealed the potential roles of Long non‑coding RNAs (lncRNAs) in cognitive dysfunction in T2D. The current research aims to demonstrate the specific expression patterns of lncRNA-mRNA in the hippocampi of T2D db/db mice exhibiting cognitive impairment. In this study, the results from behavioral tests showed that T2D db/db mice displayed short-term and spatial working memory deficits compared to db/m mice. Furthermore, western blot analysis demonstrated that compared with db/m mice, p-GSK3β (ser9) protein levels were markedly elevated in T2D db/db mice (P < 0.01). In addition, though not statistically significant, the ratio of p-Tau (Ser396) to Tau 46, α-Synuclein expression, and p-GSK3α (ser21) expression were also relatively higher in T2D db/db mice than in db/m mice. The microarray profiling revealed that 75 lncRNAs and 26 mRNAs were dysregulated in T2D db/db mice (> 2.0 fold change, P < 0.05). GO analysis demonstrated that the differentially expressed mRNAs participated in immune response, extracellular membrane-bounded organelle, and extracellular region. KEGG analysis revealed that the differentially expressed mRNAs were mainly involved in one carbon pool by folate, glyoxylate and dicarboxylate metabolism, autophagy, glycine, serine and threonine metabolism, and B cell receptor signaling pathway. A lncRNA‑mRNA coexpression network containing 71 lncRNAs and 26 mRNAs was built to investigate the interaction between lncRNA and mRNA. Collectively, these results revealed the differential hippocampal expression profiles of lncRNAs in T2D mice with cognitive dysfunction, and the findings from this study provide new clues for exploring the potential roles of lncRNAs in the pathogenesis of cognitive dysfunction in T2D.

Ror2 signaling regulated by differential Wnt proteins determines pathological fate of muscle mesenchymal progenitors

Skeletal muscle mesenchymal progenitors (MPs) play a critical role in supporting muscle regeneration. However, under pathological conditions, they contribute to intramuscular adipose tissue accumulation, involved in muscle diseases, including muscular dystrophy and sarcopenia, age-related muscular atrophy. How MP fate is determined in these different contexts remains unelucidated. Here, we report that Ror2, a non-canonical Wnt signaling receptor, is selectively expressed in MPs and regulates their pathological features in a differential ligand-dependent manner. We identified Wnt11 and Wnt5b as ligands of Ror2. In vitro, Wnt11 inhibited MP senescence, which is required for normal muscle regeneration, and Wnt5b promoted MP proliferation. We further found that both Wnts are abundant in degenerating muscle and synergistically stimulate Ror2, leading to unwanted MP proliferation and eventually intramuscular adipose tissue accumulation. These findings provide evidence that Ror2-mediated signaling elicited by differential Wnts plays a critical role in determining the pathological fate of MPs.

Deciphering lipoprotein(a) atherogenicity with use of high-throughput proteomics

Abstract Background Accumulating observational and genetic evidence suggests that lipoprotein(a) [Lp(a)], is significantly more atherogenic than other apolipoprotein-B containing particles. Systemic inflammation is thought to mediate the atherogenic effects of Lp(a). Previous studies have predominantly focused on single inflammatory biomarkers, an approach that fails to capture the broader molecular response to elevated Lp(a) levels. Purpose The aim of this study was to derive a proteome-wide signature of plasma Lp(a) concentrations and subsequently identify the pathways through which Lp(a) influences the risk of coronary artery disease (CAD). Methods This study included 41,123 UK Biobank participants with baseline Lp(a) measurements who also underwent a proteomic assessment. Relative concentration of 2,920 proteins was quantified in EDTA plasma samples using a high-throughput proximity extension assay. Lp(a)-associated proteins were identified in linear regression models, adjusting for age, sex, body mass index, race, smoking status, estimated glomerular filtration rate, medication use, and apolipoprotein B. Proteins linked with Lp(a) concentration were then evaluated for their association with incident CAD risk using Cox proportional hazards models. Significant traits were further included in pathway enrichment analysis. Results Out of 2,920 analyzed proteins (Figure 1), 140 showed a positive association with Lp(a) concentration, while 336 exhibited a negative association after adjustment for multiple testing (False discovery rate &amp;lt; 0.05). The strongest positive associations were observed for apolipoprotein F, group 10 secretory phospholipase A, and C4b-binding protein beta chain. The strongest negative associations were observed for asporin, aminoacylase-1, and retinol-binding protein 5. Among 140 proteins positively associated with Lp(a), 49 were associated with an increased risk of CAD. Conversely, among the 336 proteins negatively associated with Lp(a), 10 were associated with a decreased risk of CAD. Pathway enrichment analysis (Figure 2) indicated that proteins linked with both Lp(a) levels and CAD risk predominantly upregulated pathways related to peptide-ligand receptor signalling, platelet degranulation, neutrophil degranulation, and cytosolic calcium response. Conversely, pathways related to HDL remodeling, PI3K/AKT, KIT, and nuclear receptor signalling were downregulated. Conclusions The greater atherogenic potential of Lp(a) may be attributable to the modulation of several molecular pathways, particularly those involving platelet and neutrophil responses, cell signalling, and lipoprotein metabolism.

Structural Basis for Chemerin Recognition and Signaling Through Its Receptors

Chemerin is a chemotactic adipokine that participates in a multitude of physiological processes, including adipogenesis, leukocyte chemotaxis, and neuroinflammation. Chemerin exerts biological functions through binding to one or more of its G protein-coupled receptors (GPCRs), namely chemokine-like receptor 1 (CMKLR1), G protein-coupled receptor 1 (GPR1), and CC-motif receptor-like 2 (CCRL2). Of these receptors, CMKLR1 and GPR1 have been confirmed as signaling receptors of chemerin, whereas CCRL2 serves as a chemerin-binding protein without transmembrane signaling. High-resolution structures of two chemerin receptors are now available thanks to recent advancements in structure biology. This review focuses on the structural perspectives of the chemerin receptors with an emphasis on the structure–activity correlation, including key components of the two receptors for ligand recognition and conformational changes induced by chemerin and its derivative peptides for G protein activation. There are also comparisons between the two chemerin receptors and selected GPCRs with peptide ligands for better appreciation of the shared and distinct features of the chemerin receptors in ligand recognition and transmembrane signaling, and in the evolution of this subclass of GPCRs.

Inhibition of B cell activation by Ibrutinib improves cardiac function in experimental myocardial infarction in mice

Abstract Background Bruton's tyrosine kinase (BTK) is a key downstream mediator of B cell receptor (BCR) signaling. Upon BCR cross-linking, phosphorylated BTK modulates B cell activation, proliferation, and differentiation. Ibrutinib, which is clinically used in B-cell malignancies, irreversibly binds to the BTK kinase domain and blunts downstream BTK signaling. Purpose Here, we aimed to monitor B cell dynamics and activation in experimental myocardial infarction (MI) in mice, and evaluate the effect of B cell inhibition by Ibrutinib in cardiac function. Methods MI was induced in male 10-week-old C57BL/6 mice by permanent LAD ligation and Ibrutinib (25 mg/kg/day) was given in the drinking water. After 3, 7, 14, and 28 days, single cell suspensions were prepared for flow cytometry from peripheral blood, spleen, mediastinal lymph nodes (MLNs), and the bone marrow, as well as from the remote and infarcted myocardium. Total B cells and B cell subsets were quantified in the different locations by flow cytometry and B cell activation was monitored by BTK551 phosphorylation. After 28 days, cardiac function was evaluated by echocardiography. Results We found that total B cell numbers decrease in blood and spleen, and increase in MLNs, while plasma cells and plasmablasts increased in the infarcted heart on day 7 and 14 after MI. In the bone marrow, hematopoietic stem cells (HSC) increase after MI, while common lymphoid progenitors (CLP) and early-stage B cell progenitors (pre-pro and pro B cells) peak at day 7 after MI. The later-stage B cell progenitors (pre and immature B cells) showed a biphasic response, with an early decrease after 7 days and a later increase on day 14. Compared to the control group (vehicle), Ibrutinib treatment decreased B cell numbers in MLN and spleen by 27% and 14%, respectively, as well as decreased mature B cells by 28% in the bone marrow on day 28 after MI. Both BTK expression and phosphorylation in pro-B cells were inhibited by Ibrutinib by 8% and 15%, respectively. The inhibition of BTK phosphorylation was also evident in MLNs and spleen. Notably, Ibrutinib-treated mice showed an improved cardiac function on day 28 after MI, with stroke volume (SV) elevated by 41%, left ventricular ejection fraction (LVEF) elevated from 20% to 36% (p &amp;lt; 0.05), and fractional shortening (FS) elevated from 8.8% to 17.59% (p &amp;lt; 0.05). Conclusion Experimental MI leads to B cell lymphopoiesis in the bone marrow, mobilization into the infarcted myocardium, and activation in peripheral lymphoid organs. Ibrutinib treatment inhibits B cell development in the bone marrow, as well as B cell activation in peripheral lymphoid organs, and improves cardiac function post MI. Our data provides a meaningful insight for targeting B cells for the clinical treatment of patients with MI.Figure

Transcriptional responses to direct and indirect TGFB1 stimulation in cancerous and noncancerous mammary epithelial cells

BackgroundTransforming growth factor beta (TGFβ) is important for the morphogenesis and secretory function of the mammary gland. It is one of the main activators of the epithelial–mesenchymal transition (EMT), a process important for tissue remodeling and regeneration. It also provides cells with the plasticity to form metastases during tumor progression. Noncancerous and cancer cells respond differently to TGFβ. However, knowledge of the cellular signaling cascades triggered by TGFβ in various cell types is still limited.MethodsMCF10A (noncancerous, originating from fibrotic breast tissue) and MCF7 (cancer, estrogen receptor-positive) breast epithelial cells were treated with TGFB1 directly or through conditioned media from stimulated cells. Transcriptional changes (via RNA-seq) were assessed in untreated cells and after 1–6 days of treatment. Differentially expressed genes were detected with DESeq2 and the hallmark collection was selected for gene set enrichment analysis.ResultsTGFB1 induces EMT in both the MCF10A and MCF7 cell lines but via slightly different mechanisms (signaling through SMAD3 is more active in MCF7 cells). Many EMT-related genes are expressed in MCF10A cells at baseline. Both cell lines respond to TGFB1 by decreasing the expression of genes involved in cell proliferation: through the repression of MYC (and the protein targets) in MCF10A cells and the activation of p63-dependent signaling in MCF7 cells (CDKN1A and CDKN2B, which are responsible for the inhibition of cyclin-dependent kinases, are upregulated). In addition, estrogen receptor signaling is inhibited and caspase-dependent cell death is induced only in MCF7 cells. Direct incubation with TGFB1 and treatment of cells with conditioned media similarly affected transcriptional profiles. However, TGFB1-induced protein secretion is more pronounced in MCF10A cells; therefore, the signaling is propagated through conditioned media (bystander effect) more effectively in MCF10A cells than in MCF7 cells.ConclusionsEstrogen receptor-positive breast cancer patients may benefit from high levels of TGFB1 expression due to the repression of estrogen receptor signaling, inhibition of proliferation, and induction of apoptosis in cancer cells. However, some TGFB1-stimulated cells may undergo EMT, which increases the risk of metastasis.

Paired single-cell RNA sequencing and T cell receptor sequencing reveals both pro- and anti-inflammatory roles of T cells in patients with calcific aortic valve disease

Abstract Background Calcified aortic valve disease (CAVD) is a chronic unresolvable inflammatory disorder that affects 25% of adults over 65 years old, leading to aortic stenosis, heart failure, and death [1]. Since the molecular mechanisms of its pathogenesis are not well understood, therapies to treat root causes of the disease remain to be developed, with valve replacement as the major intervention strategy currently. Increasing evidence indicates that substantial T cells infiltrate in the aortic valve during calcification, and clonal expanded CD8+ T cells have been identified in the calcificed aortic valve by bulk T cell receptor (TCR) repertoire sequencing [2]. Purpose To decipher T cell heterogenity and understand the precise mechanisms of T cell subsets involving CAVD progression as a basis for novel therapeutic targets. Methods In Cohort 1, we collected aortic valves from CAVD (n=3) and healthy (n=2) patients for single-cell RNA sequencing (scRNA-seq). In Cohort 2, we performed paired scRNA-seq and TCR sequencing (scTCR-seq) on aortic valves obtained from CAVD (n=3) and healthy (n=3) patients to evaluate both gene expression and clonality. Pathway enrichment analysis and cell-cell interaction analysis elucidated the function of T cells in the calcificied valves. Immunohistochemistry and fluorescence-activated cell sorting were recruited to verify the key findings. Results scRNA-seq demonstrated a conversion from anti-inflammatory regulatory T (Treg) cells towards pro-inflammatory T helper 17 (Th17) cells in the calcificied aortic valve. Paired scRNA-seq and scTCR-seq revealed CAVD-related signaling pathways (osteoclast differentiation, NOD-like receptor signaling pathways, IL-17 signaling pathways) significantly upregulated in highly expanded CD8+ T cells in the calcified valve, with upregulation of pro-inflammatory mediators such as IFNG, CCL4 and CCL5, suggesting pro-inflammation functions in clonally expanded T cells. Moreover, we characterized tissue-resident memory T cells, which resembled similar transcriptome and TCR clonality as exhausted T cells in calcified valves. These cells up-regulated anti-inflammation-related transcriptomes but their cellular fraction decreased in calcified valves, implying anti-inflammatory functions of these tissue-resident memory and exhausted T cells. Conclusion This study elucidates transcriptomic and immune profiling of T cells in the calcified aortic valve, therefore shedding light on the pathophysiological mechanisms underlying aortic valve calcification from the novel perspective of tissue-specific T lymphocytes, providing promising targets for immune checkpoint-based therapeutic interventions.

Sequential versus concomitant treatment of androgen receptor signaling inhibitors and docetaxel for metastatic hormone-sensitive prostate cancer: an network meta-analysis.

Androgen receptor signaling inhibitors (ARSis), when administered sequentially or in combination with docetaxel and androgen deprivation therapy (ADT), have been shown to enhance overall survival (OS) and progression-free survival (PFS) in patients with metastatic hormone-sensitive prostate cancer (mHSPC). Nonetheless, the optimal sequence for administering chemotherapy and ARSis remains to be determined. To compare the efficacy of ARSis sequential therapy with ARSis combined therapy for mHSPC, and to evaluate the efficacy and safety of different combination regimens. The PubMed, Embase, Cochrane Central, and ClinicalTrials.gov databases were searched from their inception through 14 July 2024, to identify eligible phase III randomized clinical trials (RCTs) evaluating the combination or sequential use of docetaxel + ADT with abiraterone, enzalutamide, apalutamide, or darolutamide. The outcomes of interest included OS, PFS, time to prostate-specific antigen (PSA) progression, grade 3-5 adverse events (AEs), and serious adverse events (SAEs). Five RCTs involving 2836 patients were included in the analysis. When comparing ARSis sequential therapy to ARSis combined therapy, no significant differences were observed in OS (Hazard Ratio (HR): 1.17, 95% Confidence Interval (CI): 0.69-1.96), PFS (HR: 1.03, 95% CI: 0.47-2.22), or time to PSA progression (HR: 0.48, 95% CI: 0.03-7.69). Within the different ARSis combined regimens, the triple therapies involving enzalutamide, abiraterone, and darolutamide demonstrated comparable efficacy and safety profiles in the overall population, and their efficacy in patients with high-volume disease or low-volume disease was also similar. ARSis sequential therapy did not significantly differ from ARSis combined therapy in improving OS and PFS among patients with mHSPC, and thus can be considered as a viable treatment option.

Prediction of cardiovascular outcomes by subtle changes in the peripheral immune cell landscape - insights from the LURIC single cell RNA-sequencing study (LuRNA)

Abstract Background and Aims Atherosclerosis and its clinical sequelae, myocardial infarction and stroke, represent the main causes of death worldwide. Although preclinical evidence has suggested the existence of an inflammatory response driving disease, the extend of cellular alterations in human atherosclerosis remains enigmatic. Here, we employ single cell RNA-sequencing (scRNA-seq) on peripheral blood mononucleated cells (PBMCs) in a well-defined cardiovascular risk cohort from the "Ludwigshafen Risk and Cardiovascular Health (LURIC) trial" to define changes in the immune cell landscape in atherosclerotic patients. Methods and Results Of 3317 patients enrolled in the LURIC trial between 1997 and 2000, we selected individuals with stable coronary-artery disease (CAD) (n=31) and healthy patients (no CAD) (n=16) by propensity score matching, adjusted for CRP, NTproBNP, Troponin T, LDL-C, and Cystatin-C, in a case-control design. scRNA-seq was performed by droplet sequencing on PBMCs stored in liquid nitrogen. Individual data sets were integrated and changes between healthy individuals and patients with CAD were evaluated on numeric and transcriptional level. Single cell transcriptomes were annotated using an established CITE-seq reference atlas. While bulk RNA-sequencing of PBMC preparations revealed only minor changes between both conditions, we identified several leukocyte populations on a single cell level with specific transcriptomes that were differentially regulated between both conditions. Interestingly, we found that several subsets of Natural Killer (NK) cells, T cells with an enrichment of proliferation-associated pathways, and a population resembling hematopoietic stem cells were more frequent in patients with CAD, while naïve phenotypes of B and T cells were overrepresented in the absence of CAD. Consistently, most T and B cell populations in patients with CAD were enriched in pathways associated with cell activation, immune receptor signalling, and differentiation. In addition, we detected restricted repertoires of T cell receptor sequences in several adaptive immune cell subtypes from patients with CAD, suggestive of increased cellular clonality and antigen-specificity. Finally, in a comparison of cellular frequencies with cardiovascular outcomes over more than 15 years, several immune cell subsets and cell-type specific transcriptional programs predicted cardiovascular death in this case-control scenario in multi-variate adjusted regression analysis. Notably, addition of scRNA-seq derived parameters was superior to traditional risk prediction with clinical characteristics and soluble biomarkers alone. Conclusion Employing scRNAseq, we demonstrate that atherosclerosis is associated with a profound change in the circulating immune cell landscape even in the absence of measurable differences in inflammatory biomarkers. These findings propose the usage of scRNAseq for the discovery of outcome-relevant cellular biomarkers in the future.

Huang-Pu-Tong-Qiao Formula Alleviates Hippocampal Neuron Damage by Inhibiting NLRP3 Inflammasome-mediated Pyroptosis in Alzheimer's Disease.

Huang-Pu-Tong-Qiao (HPTQ), a Traditional Chinese Medicine formula, has achieved remarkable efficacy in clinically treating Alzheimer's disease (AD). Pyroptosis refers to the inflammatory necrosis of cells, which contributes to AD pathological progression. However, it is unclear whether the therapeutic effect of HPTQ on AD is related to reducing pyroptosis. In this study, the network pharmacology analysis was used to predict the molecular mechanism of HPTQ in treating AD and validated our hypothesis through mice and cell experiments. APP/PS1 transgenic mice and Aβ25-35-injured HT22 cells were used as AD models in vivo and in vitro. The pharmacological effects and mechanisms of HPTQ on AD were evaluated by Morris water maze, Y-maze, transmission electron microscope, immunofluorescence, Hoechst/PI staining, western blot, and ELISA. Network pharmacology reveals the correlation between the therapeutic effect of HPTQ on AD and the NOD-like receptor signaling pathway. In APP/PS1 mice, HPTQ reduced the escape latency and maintained cell membrane integrity. In HT22 cells, 15% HPTQ-medicated serum and 10 µM MCC950 increased cell viability and decreased PI positive rate compared with the Model group. In addition, HPTQ treatment in AD animal and cell models reduced the protein expressions of NLRP3, ASC, cleaved caspase-1, GSDMD, GSDMD-N, IL-1β, and IL-18. The experimental results of MCC950 specifically inhibiting the NLRP3 expression suggested that HPTQ might reduce neuronal pyroptosis by reducing NLRP3 inflammasome. Network pharmacology and experimental validation suggested that HPTQ alleviated NLRP3 inflammasome-mediated neuronal pyroptosis in AD, which could provide valuable candidate drugs for AD clinical treatment.

Targeting the VEGFR2 signaling pathway for angiogenesis and fibrosis regulation in neovascular age-related macular degeneration

Neovascular age-related macular degeneration (nAMD) is characterized by abnormal blood vessel growth from the choroid, leading to complications and eventual blindness. Despite anti-VEGF therapy, subretinal fibrosis remains a major concern, as VEGF/VEGF receptor-2 (VEGFR2) signaling can contribute to both angiogenesis and fibrosis. For the identification of the aqueous humor proteome, we performed liquid chromatography with tandem mass spectrometry analysis. To investigate the potential therapeutic effects of targeting the VEGF signaling pathway using apatinib, a highly selective VEGFR2 tyrosine kinase inhibitor, this study employed in vitro (THP-1 conditioned media-treated ARPE-19 cells) and in vivo (laser-induced choroidal neovascularization mouse) models of nAMD. This study revealed elevated VEGFR2 protein levels in the aqueous humor of nAMD patients, suggesting a potential target to mitigate neovascularization and fibrosis in nAMD. Apatinib effectively reduced VEGFA and αSMA levels in both in vitro and in vivo models. Moreover, apatinib showed improvement in laser-induced subretinal hyper-reflective lesions. The action mechanism was linked to the inhibition of VEGFR2 activation, leading to the suppression of both angiogenesis and fibrosis through the downregulation of STAT3 phosphorylation. Therefore, the VEGFR2 signaling pathway appears to play a central role in the development of nAMD by regulating both angiogenesis and fibrosis.

Exploring Ethnic Variability in Aryl Hydrocarbon Receptor Signaling: Delineating Differences in Prostate Cancer Outcomes Between African American and Caucasian Populations

Exploring Ethnic Variability in Aryl Hydrocarbon Receptor Signaling: Delineating Differences in Prostate Cancer Outcomes Between African American and Caucasian Populations

Effects of positive mGlu5 modulation on D2 signaling and nicotine-conditioned place preference: Mechanisms of epigenetic inheritance in a transgenerational model of drug abuse vulnerability in psychosis.

The metabotropic glutamate type 5 (mGlu5) receptor has emerged as a potential target for the treatment of psychosis that is suggested to have greater efficacy than antipsychotic medications that are currently utilized. This study sought to elucidate mechanisms of therapeutic action associated with the modulation of the mGlu5 receptor in a disordered system marked by dopamine dysfunction. We further explored epigenetic mechanisms contributing to heritable transmission of a psychosis-like phenotype in a novel heritable model of drug abuse vulnerability in psychosis. F1 generation male and female Sprague-Dawley rats that were the offspring of two neonatal quinpirole-treated (QQ) or two saline-treated (SS) animals were tested on nicotine-conditioned place preference (CPP). Regulators of G protein signaling 9 (RGS9) and β-arrestin 2 (βA2), which mediate dopamine (DA) D2 signaling, were measured in the nucleus accumbens shell, prelimbic and infralimbic cortices. Reduced Representation Bisulfite Sequencing (RRBS) was used to analyze the cytosine methylation in these brain regions. Pretreatment with the mGlu5-positive allosteric modulator 3-Cyano-N-(1,3-diphenyl-1H-pyrazol-5-yl)benzamide (CDPPB) 20 min prior to conditioning trials blocked enhanced nicotine CPP and mitigated aberrant G protein-dependent and -independent signaling in QQ animals. RRBS analysis revealed region-specific changes in several pathways, including nicotine addiction, dopamine synapses, and neural connectivity. These results reveal an important region-specific mechanism of action for CDPPB in a system marked by enhanced DAD2 receptor signaling. Results additionally reveal DNA methylation as an epigenetic mechanism of heritability, further validating the current model as a useful tool for the study of psychosis and comorbid nicotine use.

Aging alters the effect of adiponectin receptor signaling on bone marrow-derived mesenchymal stem cells.

Adiponectin receptor signaling represents a promising therapeutic target for age-related conditions such as osteoporosis and diabetes. However, the literature presents conflicting evidence regarding the role of adiponectin signaling in bone homeostasis and fracture repair across different health states, ages, and disease conditions. These inconsistencies may arise from the complex endocrine and paracrine feedback mechanisms regulating adiponectin, as well as the variability in adiponectin isoforms and receptor expressions. In this study, we observed differential expression of adiponectin receptors in the bone marrow (BM) of aged mice, characterized by elevated levels of adiponectin receptor 2 and reduced levels of receptor 1, as corroborated by both single-cell sequencing and invivo staining. Additionally, circulating levels of adiponectin and its local expression were significantly higher in aged mice compared to younger counterparts. Treatment with adiponectin receptor agonist, AdipoRon, enhanced bone regeneration and repair in young mice by promoting osteogenesis and reducing osteoclastogenesis. Conversely, in aged mice, AdipoRon treatment led to cellular senescence, delayed bone repair, and inhibited osteogenic activity. Notably, the adiponectin receptor 1-Wnt and adiponectin receptor 2-MAPK and mTOR signaling pathways were differentially activated in AdipoRon-treated BM mesenchymal stem cells from young and aged mice. Additionally, the NF-κB, and AKT pathways were consistently downregulated in BM macrophages of both age groups following AdipoRon administration. In conclusion, aging significantly modulates the impact of adiponectin receptor signaling on BM mesenchymal stem cells. This modulation is potentially attributable to changes in receptor transcription and distribution, as well as differential activation of downstream signaling pathways.

EXPRESS: Combined treatment with ruxolitinib and MK-2206 inhibits ERα activity by inhibiting MAPK signaling in BT474 breast cancer cells.

Triple-positive breast cancer (TPBC) is a type of breast cancer that overexpresses estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor-2 (HER2). Dysregulation of estrogen receptor signaling has been implicated in the pathogenesis of breast cancer. ERα activation triggers the production of second messengers, including cAMP, leading to the activation of signals such as PI3K/AKT or Ras/MAPK. Ruxolitinib is a specific inhibitor of JAK1/JAK2. MK-2206 is an allosteric inhibitor of the Akt. The limitations of the use of ruxolitinib and MK-2206 as single agents necessitate the development of combination therapies with other drugs. This study is the first to investigate the effects of combining ruxolitinib with MK-2206 on MAPK and PI3K/AKT signaling in BT474 breast cancer cells. Additionally, this work aimed to increase the anticancer effects of cotreatment with MK-2206 and ruxolitinib. Ruxolitinib, MK-2206, and their combination reduced cell viability in a dose- and time-dependent manner, as determined by MTT assays after 48 hours of treatment. Colony formation and wound healing assays demonstrated that MK-2206 exhibited a synergistic anti-proliferative effect. The effects of ruxolitinib, MK-2206, and their combination on PI3K/AKT and MAPK signaling were assessed via western blotting. Ruxolitinib and MK-2206 combined treatment inhibits cell death in BT474 cells by downregulating ERα, Src-1, ERK1/2, SAPK/JNK, and c-Jun. Our results revealed the relationships among the ERα, PI3K/AKT, and MAPK signaling pathways in ER+ breast cancer cells. Understanding the interactions among ERα, PI3K-AKT-mTOR, and MAPK could lead to novel combination therapies.