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Despite extensive research, the genes/proteins and pathways responsible for the physiological effects of estrogen remain elusive. In this study, we determined the effect of estrogen on global protein expression in breast cancer MCF7 cells using a proteomic method. The expression of 77 cytosolic, 74 nuclear, and 81 membrane/organelle proteins was significantly altered by 17-β-estradiol (E2). Protein enrichment analyses suggest that E2 may stimulate cell division primarily by promoting the G1 to S phase transition and advancing the G2/M checkpoint. The effect of E2 on cell survival was complex, as it could simultaneously enhance and inhibit apoptosis. Bioinformatics analysis suggests that E2 may enhance apoptosis by promoting the accumulation of the pore-forming protein Bax in the mitochondria and inhibit apoptosis by activating the PI3K/AKT/mTOR signaling pathway. We verified the activation of the PI3K signaling and the accumulation of Bax in the membrane/organelle fraction in E2-treated cells using immunoblotting. Treatment of MCF7 cells with E2 and the PI3K inhibitor Ly294002 significantly enhanced apoptosis compared to those treated with E2 alone, suggesting that combining estrogen with a PI3K inhibitor could be a promising strategy for treating ERα-positive breast cancer. Interestingly, many of the E2-upregulated proteins contained the HEAT, KH, and RRM domains.

High-grade neuroendocrine cervical cancers (NETc) are exceedingly rare, highly aggressive tumors. We analyzed 64 NETc tumor samples by whole-exome sequencing (WES). Human papillomavirus DNA was detected in 65.6% (42/64) of the tumors. Recurrent mutations were identified in PIK3CA, KMT2D/MLL2, K-RAS, ARID1A, NOTCH2, and RPL10. The top mutated genes included RB1, ARID1A, PTEN, KMT2D/MLL2, and WDFY3, a gene not yet implicated in NETc. Somatic CNV analysis identified two copy number gains (3q27.1 and 19q13.12) and five copy number losses (1p36.21/5q31.3/6p22.2/9q21.11/11p15.5). Also, gene fusions affecting the ACLY-CRHR1 and PVT1-MYC genes were identified in one of the eight samples subjected to RNA sequencing. To resolve evolutionary history, multiregion WES in NETc admixed with adenocarcinoma cells was performed (i.e., mixed-NETc). Phylogenetic analysis of mixed-NETc demonstrated that adenocarcinoma and neuroendocrine elements derive from a common precursor with mutations typical of adenocarcinomas. Over one-third (22/64) of NETc demonstrated a mutator phenotype of C > T at CpG consistent with deficiencies in MBD4, a member of the base excision repair (BER) pathway. Mutations in the PI3K/AMPK pathways were identified in 49/64 samples. We used two patient-derived-xenografts (PDX) (i.e., NET19 and NET21) to evaluate the activity of pan-HER (afatinib), PIK3CA (copanlisib), and ATR (elimusertib) inhibitors, alone and in combination. PDXs harboring alterations in the ERBB2/PI3K/AKT/mTOR/ATR pathway were sensitive to afatinib, copanlisib, and elimusertib (P < 0.001 vs. controls). However, combinations of copanlisib/afatinib and copanlisib/elimusertib were significantly more effective in controlling NETc tumor growth. These findings define the genetic landscape of NETc and suggest that a large subset of these highly lethal malignancies might benefit from existing targeted therapies.

Ruxolitinib reduces spleen volume, improves symptoms, and increases survival in patients with intermediate- or high-risk myelofibrosis. However, suboptimal response may occur, potentially because of signaling via the phosphoinositide 3-kinase (PI3K)/protein kinase B pathway. This phase 2 study evaluated dosing, efficacy, and safety of add-on PI3Kδ inhibitor parsaclisib for patients with primary or secondary myelofibrosis with suboptimal response to ruxolitinib. Eligible patients remained on a stable ruxolitinib dose and received add-on parsaclisib 10 or 20 mg, once daily for 8 weeks, and once weekly thereafter (daily-to-weekly dosing; n = 32); or parsaclisib 5 or 20 mg, once daily for 8 weeks, then 5 mg once daily thereafter (all-daily dosing; n = 42). Proportion of patients achieving a ≥10% decrease in spleen volume at 12 weeks was 28% for daily-to-weekly dosing and 59.5% for all-daily dosing. Proportions of patients achieving ≥50% decrease at week 12 in Myelofibrosis Symptom Assessment Form and Myeloproliferative Neoplasms Symptom Assessment Form symptom scores were 14% and 18% for daily-to-weekly dosing, and 28% and 32% for all-daily dosing, respectively. Most common nonhematologic treatment-emergent adverse events were nausea (23%), diarrhea (22%), abdominal pain and fatigue (each 19%), and cough and dyspnea (each 18%). New-onset grade 3 and 4 thrombocytopenia were observed in 19% of patients, each dosed daily-to-weekly, and in 26% and 7% of patients dosed all-daily, respectively, managed with dose interruptions. Hemoglobin levels remained steady. The addition of parsaclisib to stable-dose ruxolitinib can reduce splenomegaly and improve symptoms, with manageable toxicity in patients with myelofibrosis with suboptimal response to ruxolitinib. This trial was registered at www.clinicaltrials.gov as #NCT02718300.

INTRODUCTION: The chromosome 22q11.2 deletion syndrome (22q11.2DS) is characterized by a well-defined microdeletion and is associated with a wide range of brain-related phenotypes including schizophrenia spectrum disorders (SCZ), autism spectrum disorders (ASD), anxiety disorders and attention deficit disorders (ADHD). The typically deleted region in 22q11.2DS contains multiple genes which haploinsufficiency has the potential of altering the protein and the metabolic profiles. OBJECTIVES: Alteration in metabolic processes and downstream protein pathways during the early brain development may help to explain the increased prevalence of the observed neurodevelopmental phenotypes in 22q11.2DS. However, relatively little is known about the correlation of dysregulated protein/metabolite expression and neurobehavioral impairments in individuals who developed them over time. METHODS: In this study, we performed untargeted metabolic and proteomic analysis in plasma samples derived from 30 subjects including 16 participants with 22q11.2DS and 14 healthy controls (TD) enrolled in a longitudinal study, aiming to identify a metabolic and protein signature informing about the underlying mechanisms involved in disease development and progression. The metabolic and proteomic profiles were also compared between the participants with 22q11.2DS with and without various comorbidities, such as medical involvement, psychiatric conditions, and autism spectrum disorder (ASD) to detect potential changes among multiple specimens, collected overtime, with the aim to understand the basic underlying mechanisms involved in disease development and progression. RESULTS: We observed a large number of statistically significant differences in metabolites between the two groups. Among them, the levels of taurine and arachidonic acid were significantly lower in 22q11.2DS compared to the TD group. In addition, we identified 16 proteins that showed significant changes in expression levels (adjusted P

ObjectiveTo identify genes that may play a role in urethral stricture and summarize the results of studies that have documented variations in gene expression among individuals with urethral stricture compared to healthy individuals.MethodsA systematic search was conducted in Cochrane, Ovid, Web of Science, and PubMed, limiting the results to articles published between January 1, 2000 and January 30, 2023. Only studies comparing the difference in gene expression between individuals with urethral stricture and healthy individuals utilizing molecular techniques to measure gene expression in blood, urine, or tissue samples were included in this systematic review. Gene network and pathway analyses were performed using Cytoscape software, with input data obtained from our systematic review of differentially expressed genes in urethral stricture.ResultsFour studies met our criteria for inclusion. The studies used molecular biology methods to quantify gene expression data from specimens. The analysis revealed gene expressions of CXCR3 and NOS2 were downregulated in urethral tissue samples, while TGFB1, UPK3A, and CTGF were upregulated in plasma, urine and urethral tissue samples, respectively, in patients with urethral stricture compared to healthy controls. The analysis demonstrated that the most significant pathways were associated with phosphoinositide 3-kinase (PI3 kinase) and transforming growth factor beta 1/suppressor of mothers against decapentaplegic (TGF-β1/SMAD) signaling pathways.ConclusionThis systematic review identified gene expression variations in several candidate genes and identified underlying biological pathways associated with urethral stricture. These findings could inform further research and potentially shift treatment and prevention strategies for urethral stricture.

The inner cell mass (ICM) of early mouse embryos is specified into epiblast (Epi) and primitive endoderm (PrE) lineages during blastocyst formation. The antagonistic transcription factors (TFs) NANOG and GATA-binding protein 6 (GATA6) in combination with fibroblast growth factor (FGF)/extracellular-signal-regulated kinase (ERK) signaling are central actors in ICM fate choice. However, what initiates the specification of ICM progenitors into Epi or PrE and whether other factors are involved in this process has not been fully understood yet. Here, we show that phosphoinositide 3-kinase (PI3K)/protein kinase B (AKT) is constitutively active during preimplantation development. Using pharmacological inhibition, we demonstrate that PI3K/AKT enables the formation of a functional ICM capable of giving rise to both the Epi and the PrE: it maintains the expression of the TF NANOG, which specifies the Epi, and confers responsiveness to FGF4, which is essential for PrE specification. Our work thus identifies PI3K/AKT signaling as an upstream regulator controlling the molecular events required for both Epi and PrE specification. [Display omitted] • PI3K signaling is active throughout preimplantation development • PI3K inhibition impedes the differentiation of ICM progenitors • PI3K/AKT/GSK3 axis supports the expression of NANOG and other pluripotency TFs • GATA6 and FGF4 are unable to properly specify primitive endoderm without PI3K Geiselmann and Micouin et al. identify PI3K signaling as a regulator of fate acquisition for the inner cells of the mouse embryo. PI3K not only supports the expression of key pluripotency transcription factors but also confers competence to engage in PrE differentiation in response to FGF signaling. [ABSTRACT FROM AUTHOR]

We have recently shown that fluoxetine (FX) suppressed polyinosinic-polycytidylic acid-induced inflammatory response and endothelin release in human epidermal keratinocytes, via the indirect inhibition of the phosphoinositide 3-kinase (PI3K)-pathway. Because PI3K-signaling is a positive regulator of the proliferation, in the current, highly focused follow-up study, we assessed the effects of FX (14 µM) on the proliferation and differentiation of human epidermal keratinocytes. We found that FX exerted anti-proliferative actions in 2D cultures (HaCaT and primary human epidermal keratinocytes [NHEKs]; 48- and 72-h; CyQUANT-assay) as well as in 3D reconstructed epidermal equivalents (48-h; Ki-67 immunohistochemistry). Importantly, FX did not influence epidermal thickness (hematoxylin-eosin staining), and it did not have a major impact on the differentiation-associated alteration of the gene expression pattern (24-h treatments; RNA-Seq). Moreover, neither keratin (K)-1, nor K10 expression was altered by FX in NHEKs (RT-qPCR) or in 3D epidermal equivalents (semi-quantitative immunohistomorphometry). FX did not influence differentiation-induced up-regulation of occludin (RT-qPCR; NHEKs), and did not alter differentiation-associated barrier forming capacity of epidermal keratinocytes (electrical impedance; Lucifer Yellow penetration assay). Our data indicate that, besides the previously reported combined anti-inflammatory and putative anti-pruritic effects, FX may also suppress proliferation of human epidermal keratinocytes without impairing their differentiation and barrier-forming capacity. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of this review study is to investigate the effect of curcumin on the phosphoinositide 3-kinase (PI3K)/protein kinase B (Akt) signaling pathway in various diseases. Curcumin, the main compound found in turmeric, has attracted a lot of attention for its diverse pharmacological properties. These properties have increased the therapeutic potential of curcumin in chronic diseases such as cardiovascular disease, Type 2 diabetes, obesity, non-alcoholic fatty liver disease, kidney disease, and neurodegenerative diseases. One of the main mechanisms of the effect of curcumin on health is its ability to modulate the PI3K/Akt signaling pathway. This pathway plays an important role in regulating vital cellular processes such as growth, cell survival, metabolism, and apoptosis. Disruption of the PI3K/Akt signaling pathway is associated with the incidence of several diseases. Methods: Electronic databases including PubMed, Google Scholar, and Scopus were searched with the keywords "phosphoinositide 3-kinase" AND "protein kinase B "AND "curcumin" in the title/abstract. Also, following keywords "non-alcoholic fatty liver disease" AND "diabetes" AND "obesity" AND "kidney disease" and "neurodegenerative diseases" was searched in the whole text. Results: Research indicates that curcumin offers potential benefits for several health conditions. Studies have shown it can help regulate blood sugar, reduce inflammation, and protect the heart, kidneys, and brain. Conclusion: This protective effect is partially achieved by regulating the PI3K-Akt survival pathway, which helps improve metabolic disorders and oxidative stress. By examining how curcumin affects this vital cell pathway, researchers can discover new treatment strategies for a range of diseases. [ABSTRACT FROM AUTHOR]

AbstractGastric cancer (GC) is a malignant tumor with high morbidity and mortality rates worldwide. This study aimed to investigate the effects and mechanisms of action of didymin, a dietary flavonoid glycoside, on GC treatment. Human GC cell lines Hs-746T and AGS were used to assess the effects of didymin on cell viability, cell proliferation, and cell cycle. The results showed that didymin decreased the proliferative capacity of GC cells and blocked cell cycle. Didymin decreased wound healing, invasion, and migration capacities of GC cells. Mitochondrial reactive oxygen species (ROS) levels and mitochondrial membrane potentials were reduced in cells treated with didymin. Network pharmacology analysis revealed that the therapeutic effects of didymin on AGS cells were related to the phosphatidylinositol 3-kinase (PI3K)/Akt pathway. In vivo mouse xenograft studies confirmed that didymin treatment decreased tumor cell proliferation, cell cycle protein levels, and Akt phosphorylation. The present study demonstrated that didymin regulates mitochondrial function and the PI3K/Akt pathway to inhibit cell proliferation and induce apoptosis in GC cells in vitro and in vivo. Therefore, didymin is a promising drug for the treatment of GC. [ABSTRACT FROM AUTHOR]

AbstractThe lung tumour microenvironment (TME) is composed of various cell types, including cancer cells, stromal and immune cells, as well as extracellular matrix (ECM). These cells and surrounding ECM create a stiff, hypoxic, acidic and immunosuppressive microenvironment that can augment the resistance of lung tumours to different forms of cell death and facilitate invasion and metastasis. This environment can induce chemo/radiotherapy resistance by inducing anti-apoptosis mediators such as phosphoinositide 3-kinase (PI3K)/Akt, signal transducer and activator of transcription 3 (STAT3) and nuclear factor kappa B (NF-κB), leading to the exhaustion of antitumor immunity and further resistance to chemo/radiotherapy. In addition, lung tumour cells can resist chemo/radiotherapy by boosting multidrug resistance mechanisms and antioxidant defence systems within cancer cells and other TME components. In this review, we discuss the interactions and communications between these different components of the lung TME and also the effects of hypoxia, immune evasion and ECM remodelling on lung cancer resistance. Finally, we review the current strategies in preclinical and clinical studies, including the inhibition of checkpoint molecules, chemoattractants, cytokines, growth factors and immunosuppressive mediators such as programmed death 1 (PD-1), insulin-like growth factor 2 (IGF-2) for targeting the lung TME to overcome resistance to chemotherapy and radiotherapy. [ABSTRACT FROM AUTHOR]

Ameloblastoma is a rare tumor arising from odontogenic cells that is benign, yet locally aggressive. Metastasizing ameloblastoma (METAM) is an ultra-rare ameloblastoma variant in which both primary and secondary tumors have histological features of benign ameloblastoma. This is a case report of a patient who presented with a jaw mass and subsequent lung metastases, later diagnosed as METAM. Initial treatments, including carboplatin, etoposide, and taxane-based chemotherapy, were ineffective. Molecular profiling revealed mutations including PIK3CA H1047R and BRAF V600E. The patient was enrolled in a tumor-agnostic trial and began treatment with copanlisib, a PI3K inhibitor, which resulted in a partial response and durable disease regression. After 76 cycles, she continues to tolerate therapy well with minimal adverse events. This case highlights the potential of targeted therapies such as copanlisib for treating METAM, providing a promising therapeutic option for patients with PIK3CA mutations. [ABSTRACT FROM AUTHOR]

Thienopyrimidines are an emerging class of fused pyrimidines due to their broad spectrum of pharmacological properties, including antimicrobial, anti-inflammatory, antimalarial, anticancer, etc. The anticancer activity of these compounds has been mechanistically proven via the inhibition of validated drug targets, such as EGFR, VEGFR-2, PI3K, and c-kit. In this research article, we designed and synthesized new 4-amino-substituted 2-(4-bromobenzyl)-5,6,7,8-tetrahydrobenzo[4,5]thieno[2,3- d ]pyrimidines to explore their anticancer potential. These heterocycles were designed based on pharmacophoric features of the core heterocycle, varying its C4 substitution with a variety of amines and considering cancer protein-ligand interactions with the aim to obtain potent lead molecules. The target compound-protein interaction complexes were analyzed, and lead compounds were identified based on their better binding affinity in molecular docking studies. [ABSTRACT FROM AUTHOR]

Background/Aim: Soft tissue sarcoma (STS) is a mesenchymal tumor affecting multiple organs in dogs. Previous studies identified activation of the phosphatidylinositol-3 kinase (PI3K)/protein kinase B (PKB, AKT) pathway in canine STS cell lines and clinical samples, but the underlying mechanism remains unclear. This study investigated PTEN loss, PIK3CA mutation, and EGFR over-expression as potential drivers of PI3K/AKT pathway activation in STS. Materials and Methods: We analyzed 36 canine STS samples. PTEN and EGFR expression were evaluated using immunohistochemistry, while PIK3CA and EGFR mutations were assessed through DNA sequencing. Results: PTEN was expressed in all analyzed samples, with no evidence of loss. Weak PTEN expression was observed in 12 (33.3%) samples, while 24 (66.7%) showed normal expression. DNA sequencing of PIK3CA revealed a single point mutation (c.554 A>C, H554P) in one case, but no hotspot mutations were identified. High EGFR expression was significantly correlated with elevated phospho-AKT levels (p<0.0001). Immunolabelling indicated that 30 samples (83.3%) were EGFR-positive, and 27 of these also showed positive phospho-AKT labeling. Accordingly, one missense point mutation in exon 21 of EGFR (E868K) was identified in one of 12 samples. Conclusion: EGFR over-expression, rather than PTEN loss or PIK3CA mutations, may contribute to PI3K/AKT pathway dysregulation in canine STS. Further studies with larger sample sizes and additional validation techniques are necessary to confirm these findings. [ABSTRACT FROM AUTHOR]

Starvation- or stress-induced phosphatidylinositol 3-phosphate (PtdIns3P/PI3P) production at the endoplasmic reticulum (ER) subdomains organizes phagophore assembly and autophagosome formation. Coat protein complex II (COPII) vesicles budding from ER exit site (ERES) also contribute to autophagosome formation. Whether any PtdIns3P phosphatase functions at ERES to inhibit macroautophagy/autophagy is unknown. Here we report Myotubularin 2 (MTM2) of Arabidopsis as a PtdIns3P phosphatase that localizes to ERES and negatively regulates autophagy. MTM2 binds PtdIns3P with its PH-GRAM domain in vitro and acts toward PtdIns3P in vivo. Transiently expressed MTM2 colocalizes with ATG14b, a subunit of the phosphatidylinositol 3-kinase (PtdIns3K) complex, and overexpression of MTM2 blocks autophagic flux and causes over-accumulation of ATG18a, ATG5, and ATG8a. The mtm2 mutant has higher levels of autophagy and is more tolerant to starvation, whereas MTM2 overexpression leads to reduced autophagy and sensitivity to starvation. The phenotypes of mtm2 are suppressed by ATG2 mutation, suggesting that MTM2 acts upstream of ATG2. Importantly, MTM2 does not affect the endosomal functions of PtdIns3P. Instead, MTM2 specifically colocalizes with COPII coat proteins and is cradled by the ERES-defining protein SEC16. MTM2 interacts with SEC23A with its phosphatase domain and inhibits COPII-mediated protein secretion. Finally, a role for MTM2 in salt stress response is uncovered. mtm2 resembles the halophyte Thellungiella salsuginea in its efficient vacuolar compartmentation of Na+, maintenance of chloroplast integrity, and timely regulation of autophagy-related genes. Our findings reveal a balance between PtdIns3P synthesis and turnover in autophagosome formation, and provide a new link between autophagy and COPII function.Abbreviations: ATG: autophagy related; BFA: brefeldin A; BiFC: bimolecular fluorescence complementation; CHX: cycloheximide; ConA: concanamycin A; COPII: coat protein complex II; ER: endoplasmic reticulum; ERES: ER exit site; MS: Murashige and Skoog; MTM: myotubularin; MVB: multivesicular body; PAS: phagophore assembly site; PI: phosphoinositide; TEM: transmission electron microscopy; WT: wild-type. [ABSTRACT FROM AUTHOR]

As the central hub of the secretory pathway, the Golgi apparatus plays a crucial role in maintaining cellular homeostasis in response to stresses. Recent studies have revealed the involvement of the Golgi tether, GORASP2, in facilitating autophagosome-lysosome fusion by connecting LC3-II and LAMP2 during nutrient starvation. However, the precise mechanism remains elusive. In this study, utilizing super-resolution microscopy, we observed GORASP2 localization on the surface of autophagosomes during glucose starvation. Depletion of GORASP2 hindered phagophore closure by regulating the association between VPS4A and the ESCRT-III component, CHMP2A. Furthermore, we found that GORASP2 controls RAB7A activity by modulating its GEF complex, MON1A-CCZ1, thereby impacting RAB7A's interaction with the HOPS complex. The assembly of both STX17-SNAP29-VAMP8 and YKT6-SNAP29-STX7 SNARE complexes was also attenuated without GORASP2. These findings suggest that GORASP2 helps seal autophagosomes and activate the RAB7A-HOPS-SNAREs membrane fusion machinery for autophagosome maturation, highlighting its membrane tethering function in response to stresses.Abbreviations: BafA1: bafilomycin A1; ESCRT: endosomal sorting complex required for transport; FPP: fluorescence protease protection; GEF: guanine nucleotide exchange factor; GFP: green fluorescent protein; GORASP2: golgi reassembly stacking protein 2; GSB: glucose starvation along with bafilomycin A1; HOPS: homotypic fusion and protein sorting; LAMP2: lysosomal associated membrane protein 2; MAP1LC3B: microtubule associated protein 1 light chain 3 beta; PBS: phosphate-buffered saline; PtdIns3K: phosphatidylinositol 3-kinase; PtdIns3P: phosphatidylinositol-3-phosphate; PK: proteinase K; SNARE: soluble N-ethylmaleimide-sensitive factor attachment protein receptor; SIM: structured illumination microscopy; UVRAG: UV radiation resistance associated. [ABSTRACT FROM AUTHOR]

Mutations in lipid regulator genes are a frequent cause of autism spectrum disorder, including those regulating phosphatidylinositol (PI) and phosphoinositide 3-kinase signaling. MBOAT7 encodes a key acyltransferase in PI synthesis and is mutated in an autism-related condition with neurodevelopmental delay and epilepsy. Using liquid chromatography–tandem mass spectrometry, we analyzed the PI-associated glycerolipidome in mice and humans during neurodevelopment and found dynamic regulation at times corresponding to neural apoptosis in the brains of Mboat7 knockout mice. Mboat7 function was necessary for polyunsaturated lipid synthesis and cortical neural migration, and loss resulted in massive accumulation of the precursor lysophosphatidylinositol and hyperactive mTOR signaling. Inhibiting mTOR signaling rescued migration defects. Our findings demonstrate roles for lipid remodeling during neurodevelopment and implicate lipid regulation in neuronal migration, revealing potential paths to treatment for MBOAT7 deficiency. Editor's summary: Phospholipids are an integral component of the brain, but how lipid composition changes and affects the migration of neurons in the developing brain remains elusive. Here, Tang et al. performed lipidomics on mouse brains as well as patient-derived neurons and show that neuron-specific loss of membrane-bound O-acyltransferase 7 (MBOAT7) led to an accumulation of the phosphatidylinositol precursor LPI during neuronal development. These lipidomic changes were associated with cortical migration defects. Injection of LPI into the embryonic mouse brain could phenocopy these migration defects that were alleviated by mTOR inhibition. In summary, this study identifies a role for MBOAT7 and the brain lipidome in cortical development. —Daniela Neuhofer [ABSTRACT FROM AUTHOR]

Inborn errors of immunity (IEI) are rare diseases that affect the immune system. According to the latest International Union of Immunological Societies (IUIS) classification, 485 different IEI have been identified. Even if increased susceptibility to infections is the best-known symptom, IEI are no longer defined by the higher likelihood of infections alone. Immune dysregulation with autoimmune disease and hyperinflammation, lymphoproliferation, and malignancy are common manifestations and could be the only symptoms of IEI that must be recognized. An exclusive focus on infection-centered warning signs would miss around 25% of patients with IEI who initially present with other manifestations. Timely and appropriate diagnosis and treatment are essential to enhance the quality of life (QoL) and, in some cases, survival, as patients are susceptible to life-threatening infections or autoimmunity. In addition, the advantage of early diagnosis in IEI with immune dysregulation (i.e. CTLA4 deficiency, LRBA deficiency, NF-kB1/NF-kB2 deficiency, activated phosphoinositide 3-kinase delta syndrome -APDS-) is the initiation of targeted therapies with precise re-balancing of the dysregulated immune pathways (i.e., biologicals, selective inhibitors) or definitive therapy (i.e., HSCT). [ABSTRACT FROM AUTHOR]

Metaplastic breast cancer (MpBC) is a highly chemoresistant subtype of breast cancer with no standardized therapy options. A clinical study in anthracycline-refractory MpBC patients suggested that nitric oxide synthase (NOS) inhibitor NG-monomethyl-l-arginine (L-NMMA) may augment anti-tumor efficacy of taxane. We report that NOS blockade potentiated response of human MpBC cell lines and tumors to phosphoinositide 3-kinase (PI3K) inhibitor alpelisib and taxane. Mechanistically, NOS blockade leads to a decrease in the S-nitrosylation of c-Jun NH2-terminal kinase (JNK)/c-Jun complex to repress its transcriptional output, leading to enhanced tumor differentiation and associated chemosensitivity. As a result, combined NOS and PI3K inhibition with taxane targets MpBC stem cells and improves survival in patient-derived xenograft models relative to single-/dual-agent therapy. Similarly, biopsies from MpBC tumors that responded to L-NMMA+taxane therapy showed a post-treatment reversal of epithelial-to-mesenchymal transition and decreased stemness. Our findings suggest that combined inhibition of iNOS and PI3K is a unique strategy to decrease chemoresistance and improve clinical outcomes in MpBC. Metaplastic breast cancer is a highly chemoresistant breast cancer subtype with limited therapeutic options. Here, the authors report that the NOS inhibitor, L-NMMA, sensitises metaplastic breast cancer to a selective PI3K inhibitor, alpelisib, and taxane chemotherapy via repression of c-JUN mediated epithelial-to-mesenchymal transition. [ABSTRACT FROM AUTHOR]

Background: Activated Phosphoinositide 3-Kinase (PI3K) δ Syndrome (APDS), an inborn error of immunity due to upregulation of the PI3K pathway, leads to recurrent infections and immune dysregulation (lymphoproliferation and autoimmunity). Methods: Clinical and genetic data of 28 APDS patients from 25 unrelated families were collected from fifteen Italian centers. Results: Patients were genetically confirmed with APDS-1 (n = 20) or APDS-2 (n = 8), with pathogenic mutations in the PIK3CD or PIK3R1 genes. The median age at diagnosis was 15.5 years, with a median follow-up of 74 months (range 6-384). The main presenting symptoms were respiratory tract infections alone (57%) or associated with lymphoproliferation (17%). Later, non-clonal lymphoproliferation was the leading clinical sign (86%), followed by respiratory infections (79%) and gastrointestinal complications (43%). Malignant lymphoproliferative disorders, all EBV-encoding RNA (EBER)-positive at the histological analysis, occurred in 14% of patients aged 17–19 years, highlighting the role of EBV in lymphomagenesis in this disorder. Diffuse large B-cell lymphoma was the most frequent. Immunological work-up revealed combined T/B cell abnormalities in most patients. Treatment strategies included immunosuppression and PI3K/Akt/mTOR inhibitor therapy. Rapamycin, employed in 36% of patients, showed efficacy in controlling lymphoproliferation, while selective PI3Kδ inhibitor leniolisib, administered in 32% of patients, was beneficial on both infections and immune dysregulation. Additionally, three patients underwent successful HSCT due to recurrent infections despite ongoing prophylaxis or lymphoproliferation poorly responsive to Rapamycin. Conclusions: This study underscores the clinical heterogeneity and challenging diagnosis of APDS, highlighting the importance of multidisciplinary management tailored to individual needs and further supporting leniolisib efficacy. [ABSTRACT FROM AUTHOR]

Background: Primordial follicle activation is vital for the reproduction of women with advanced age and premature ovarian insufficiency (POI). But there is a lack of effective and safe therapeutic options to activate their primordial follicles in vivo. Berberine (BBR) possesses multiple pharmacological properties, but its impact on primordial follicle activation remains unclear. Methods: The role of BBR on primordial activation was investigated by neonatal mouse ovary culture and intraperitoneal injection, and by human ovarian fragment culture. Furthermore, the effect of BBR on the quantity of ovulated oocytes was investigated by the intragastric administration of aged mice. Results: BBR in vitro culture and in vivo intraperitoneal injection significantly increased growing follicle number and phosphorylated protein kinase B (p-Akt) levels in neonatal mouse ovaries. BBR also significantly increased the relative fluorescence intensities of p-Akt in the oocytes of primordial follicles. BBR-increased the number of growing follicles and the levels of p-Akt were blocked by LY294002, an inhibitor of phosphatidylinositol 3-kinase (PI3K). Furthermore, BBR intragastric administration significantly increased the quantity of ovulated oocytes in aged mice. Moreover, BBR significantly increased growing follicle proportion and p-Akt levels in cultured human ovarian fragments. Conclusion: BBR promotes mouse and human primordial follicle activation through the PI3K/Akt pathway in oocytes, and improves the quantity of ovulated oocytes in aged mice. Our results suggest a potential use of oral medicine BBR to improve fertility in POI patients and aged women. [ABSTRACT FROM AUTHOR]

Thyroid-associated ophthalmopathy (TAO), an autoimmune disorder of the retrobulbar tissue, is present in up to 50 percent of Graves's hyperthyroidism patients. Insulin-like growth factor 1 receptor (IGF-1R) has received attention as a target for the development of therapeutic agent for TAO. IGF-1R and TSHR (thyroid stimulating hormone receptor) interact with each other to form a physical or functional complex, further promoting the development of TAO. Linsitinib, OSI-906, is an inhibitor of IGF-1R and has been reported to inhibit cell proliferation of several tumor cells. Linsitinib has been receiving attention not only for its anticancer effect, but also for its anti-inflammatory effects. It has been reported that linsitinib reduces infiltration of inflammatory cells in orbital tissues, resulting in the reduction of muscle edema and adipose tissues in an experimental murine model for Graves' disease. In the current study, we investigated the issue of whether linsitinib inhibits the IGF-1-induced proliferation of orbital fibroblasts (OFs) via the suppression of phosphatidylinositol 3-kinase (PI3K) / Akt and extracellular signal-regulated kinase (ERK) pathway. Our results showed that pretreatment with linsitinib inhibited IGF-1-induced cell proliferation and hyaluronic acid secretion in the OFs of TAO patients. In addition, our results showed that pretreatment with linsitinib inhibited IGF-1-induced phosphorylation of IGF-1Rβ at Tyr1135, Akt at Ser473, and ERK in the OFs of patients with TAO. These results indicate that linsitinib inhibits IGF-1-induced cell proliferation and hyaluronic acid secretion in the OFs of TAO patients by suppressing the PI3K/Akt and ERK pathways, validating the use of linsitinib as a novel therapeutic agent for TAO. [ABSTRACT FROM AUTHOR]

ABSTRACT Ageing of the endometrium is a critical factor that affects reproductive health, yet its intricate mechanisms remain poorly explored. In this study, we performed transcriptome profiling and experimental verification of endometrium and endometrial organoids from young and advanced age females, to elucidate the underlying mechanisms and to explore novel treatment strategies for endometrial ageing. First, we found that age‐associated decline in endometrial functions including fibrosis and diminished receptivity, already exists in reproductive age. Subsequently, based on RNA‐seq analysis, we identified several changes in molecular processes affected by age, including fibrosis, imbalanced inflammatory status including Th1 bias in secretory phase, cellular senescence and abnormal signalling transduction in key pathways, with all processes been further validated by molecular experiments. Finally, we uncovered for the first time that PI3K‐AKT‐FOXO1 signalling pathway is overactivated in ageing endometrium and is closely correlated with fibrosis and impaired receptivity characteristics of ageing endometrium. Blocking or activation of PI3K by LY294002 or 740Y‐P could attenuate the effect of ageing or accelerate dysfunction of endometrial organoids. This discovery is expected to bring new breakthroughs for understanding the pathophysiological processes associated with endometrial ageing, as well as treatment strategies to improve reproductive outcomes in women of advanced reproductive age. [ABSTRACT FROM AUTHOR]

Croton socotranus Balf.f. shrub is widely used traditionally in Asia as an anti-infective. The study was conducted for metabolite profiling, oral acute toxicity and antioxidant studies, antimicrobial activity and anticancer effect against human hepatoma (HepG2), breast cancer (MCF-7) and rhabdomyosarcoma (RD) cells. Gas chromatography-mass spectrometry analysis revealed the presence of 39 compounds, predominantly comprising fatty acids (57.76%), sesquiterpenes (24.56%) and triterpenes (9.54%). The n-hexane fraction exhibited promising antimicrobial activity and displayed a potent anti-tumour effect against HepG2, MCF-7 and RD cells with IC50 values of 3.4, 6.5 and 7.1 μg/mL, respectively. Histological examination revealed significant morphological changes consistent with the changes observed in the apoptotic mechanism of action. The molecular docking study provided insights into the rational binding modes of the identified compounds with phosphoinositide 3-kinase and poly(ADP-ribose)polymerase-1 enzymes. Our findings suggest the potential of C. socotranus as a valuable source of antimicrobial and anticancer agents. [ABSTRACT FROM AUTHOR]

Mitochondrial DNA (mtDNA) encodes genes essential for oxidative phosphorylation. The m.3243A>G mutation causes severe disease, including myopathy, lactic acidosis and stroke-like episodes (MELAS) and is the most common pathogenic mtDNA mutation in humans. We have previously shown that the mutation is associated with constitutive activation of the PI3K-AKT-MTORC1 axis. Inhibition of this pathway in patient fibroblasts reduced the mutant load, rescued mitochondrial bioenergetic function and reduced glucose dependence. We have now investigated the mechanisms that select against the mutant mtDNA under these conditions. Basal macroautophagy/autophagy and lysosomal degradation of mitochondria were suppressed in the mutant cells. Pharmacological inhibition of any step of the PI3K-AKT-MTORC1 pathway activated mitophagy and progressively reduced m.3243A>G mutant load over weeks. Inhibition of autophagy with bafilomycin A1 or chloroquine prevented the reduction in mutant load, suggesting that mitophagy was necessary to remove the mutant mtDNA. Inhibition of the pathway was associated with metabolic remodeling – mitochondrial membrane potential and respiratory rate improved even before a measurable fall in mutant load and proved crucial for mitophagy. Thus, maladaptive activation of the PI3K-AKT-MTORC1 axis and impaired autophagy play a major role in shaping the presentation and progression of disease caused by the m.3243A>G mutation. Our findings highlight a potential therapeutic target for this otherwise intractable disease.Abbreviation: ΔΨm: mitochondrial membrane potential; 2DG: 2-deoxy-D-glucose; ANOVA: analysis of variance; ARMS-qPCR: amplification-refractory mutation system quantitative polymerase chain reaction; Baf A1: bafilomycin A1; BSA: bovine serum albumin; CQ: chloroquine; Cybrid: cytoplasmic hybrid; CYCS: cytochrome c, somatic; DCA: dichloroacetic acid; DMEM: Dulbecco’s modified Eagle’s medium; DMSO: dimethylsulfoxide; EGFP: enhanced green fluorescent protein; LC3B-I: carboxy terminus cleaved microtubule-associated protein 1 light chain 3 beta; LC3B-II: lipidated microtubule-associated protein 1 light chain 3 beta; LY: LY290042; MAP1LC3B/LC3B: microtubule associated protein 1 light chain 3 beta; MELAS: mitochondrial encephalomyopathy, lactic acidosis and stroke-like episodes; MFC: mitochondrial fragmentation count; mt-Keima: mitochondrial-targeted mKeima; mtDNA: mitochondrial DNA/mitochondrial genome; MTOR: mechanistic target of rapamycin kinase; MTORC1: MTOR complex 1; OA: oligomycin+antimycin A; OxPhos: oxidative phosphorylation; DPBS: Dulbecco’s phosphate-buffered saline; PPARGC1A/PGC-1α: PPARG coactivator 1 alpha; PPARGC1B/PGC-1β: PPARG coactivator 1 beta; PI3K: phosphoinositide 3-kinase; PINK1: PTEN induced kinase 1; qPCR: quantitative polymerase chain reaction; RNA-seq: RNA sequencing; RP: rapamycin; SQSTM1/p62: sequestosome 1; TEM: transmission electron microscopy; WT: wild-type [ABSTRACT FROM AUTHOR]

Regulatory T (Treg) cells are essential for the maintenance of immunological tolerance, yet the molecular components required for their maintenance and effector functions remain incompletely defined. Inactivation of VPS34 in Treg cells led to an early, lethal phenotype, with massive effector T cell activation and inflammation, like mice lacking Treg cells completely. However, VPS34-deficient Treg cells developed normally, populated the peripheral lymphoid organs and effectively supressed conventional T cells in vitro. Our data suggest that VPS34 is required for the maintaining normal numbers of mature Treg. Functionally, we observed that lack of VPS34 activity impairs cargo processing upon transendocytosis, that defective autophagy may contribute to, but is not sufficient to explain this lethal phenotype, and that loss of VPS34 activity induces a state of heightened metabolic activity that may interfere with metabolic networks required for maintenance or suppressive functions of Treg cells. [ABSTRACT FROM AUTHOR]

WDR91 and SORF1, members of the WD repeat-containing protein 91 family, control phosphoinositide conversion by inhibiting phosphatidylinositol 3-kinase activity on endosomes, which promotes endosome maturation. Here, we report the crystal structure of the human WDR91 WD40 domain complexed with Rab7 that has an unusual interface at the C-terminus of the Rab7 switch II region. WDR91 is highly selective for Rab7 among the tested GTPases. A LIS1 homology (LisH) motif within the WDR91 N-terminal domain (NTD) mediates self-association and may contribute partly to the augmented interaction between full-length WDR91 and Rab7. Both the Rab7 binding site and the LisH motif are indispensable for WDR91 function in endocytic trafficking. For the WDR91 orthologue SORF1 lacking the C-terminal WD40 domain, a C-terminal amphipathic helix (AH) mediates strong interactions with liposomes containing acidic lipids. During evolution the human WDR91 ancestor gene might have acquired a WD40 domain to replace the AH for endosomal membrane targeting. [Display omitted] • The crystal structure of the human WDR91 WD40 domain with bound Rab7-GTP was determined • WDR91 N-terminal domain (NTD) contains a LisH self-association motif • LisH contributes to the augmented interaction between full-length WDR91 and Rab7 • The C. elegans WDR91 orthologue SORF1 uses an amphipathic helix for lipid binding Proteins from the WDR91 family control phosphoinositide conversion required for endosome maturation. By combining structural, biochemical, and cellular data, Ma et al. provide evidence that two representative members of this family WDR91 and SORF1 either use the Rab7-binding WD40 domain or an amphipathic helix for membrane targeting. [ABSTRACT FROM AUTHOR]

Signaling through the platelet-derived growth factor receptor alpha (PDGFRα) plays a critical role in craniofacial development. Phosphatidylinositol 3-kinase (PI3K)/Akt is the primary effector of PDGFRα signaling during mouse skeletal development. We previously demonstrated that Akt phosphorylates the RNA-binding protein serine/arginine-rich splicing factor 3 (Srsf3) downstream of PI3K-mediated PDGFRα signaling in mouse embryonic palatal mesenchyme (MEPM) cells, leading to its nuclear translocation. We further showed that ablation of Srsf3 in the murine neural crest lineage results in severe midline facial clefting and widespread alternative RNA splicing (AS) changes. Here, we demonstrated via enhanced UV-crosslinking and immunoprecipitation of MEPM cells that PDGF-AA stimulation leads to preferential binding of Srsf3 to exons and loss of binding to canonical Srsf3 CA-rich motifs. Through the analysis of complementary RNA-seq data, we showed that Srsf3 activity results in the preferential inclusion of exons with increased GC content and lower intron to exon length ratio. We found that Srsf3 activity downstream of PDGFRα signaling leads to retention of the receptor in early endosomes and increases in downstream PI3K-mediated Akt signaling. Taken together, our findings reveal that growth factor-mediated phosphorylation of an RNA-binding protein underlies gene expression regulation necessary for mammalian craniofacial development. [ABSTRACT FROM AUTHOR]

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Angiogenesis is a process involved in the formation of new blood capillaries from pre-existing ones. It is regulated by several anti-angiogenic molecules involved in tumor growth and metastasis. The endothelial angiopoietin Ang-Tie/PI3K/AKT growth receptor pathway is necessary for healthy vascular development. The activation of AKT is controlled by a multistep process involving phosphoinositide 3-kinase (PI3K). This article aims to provide an overview of the role and mechanism of the Ang-Tie/PI3K/AKT signaling pathways and the potential of flavonoids as anti-angiogenic drugs. Flavonoids have shown great potential in preventing angiogenesis by targeting signaling pathways and exhibit additional anti-cancer properties. Research studies have revealed that the currently available anti-angiogenic drugs do not meet the safety and efficacy standards for treating tumor growth. Phytocompounds have long been a valuable resource for the development of novel therapeutic drugs. This article explores recent findings explaining the role and mechanism of the Ang-Tie/PI3K/AKT signaling pathways, as well as the interaction of flavonoids with angiogenic signaling pathways as a novel therapeutic approach. Several investigations have shown that synergistic studies of natural phytocompounds have great potential to target these pathways to inhibit tumor growth. Therefore, flavonoid-based medications may offer a more effective synergistic strategy to treat cancer. [ABSTRACT FROM AUTHOR]

Background/Objectives: Glioblastoma is a malignant tumor with a poor prognosis for the patient due to its high lethality and limited chemotherapy available. Therefore, from the point of view of chemotherapy treatment, glioblastoma can be considered an unmet medical need. This has led to the investigation of new drugs for monotherapy or associations, acting by synergistic pharmacological mechanisms. Methods: Here, we propose the combination of Osimertinib (a potent EGFR inhibitor) and Gedatolisib (a potent PI3K/mTOR dual inhibitor) through an in vitro phenotypic study using five human GB lines and establish the cytotoxic potency, selectivity, and effect on proliferation, apoptosis, and cell cycle by simultaneously inhibiting EGFR, PI3K, and mTOR. Results: Cytotoxic potency of Gedatolisib and Osimertinib in the selected GB cell lines was determined, which highlighted the synergistic response from their combination and its impact on migration reduction, G0/G1 cell cycle arrest, GB cytotoxicity, and apoptosis-inducing effects for different GB cell lines. Conclusions: From the drug combination studies in phenotypic in vitro models, it was possible to suggest a new potential treatment for glioblastoma that justifies further safe in vivo phases of preclinical trials with the combination. [ABSTRACT FROM AUTHOR]

Background: Houge-Janssens syndrome 1 is a condition with onset in early childhood caused by heterozygous pathogenic variants in the PPP2R5D gene, which encodes a B56 regulatory subunit of the serine/threonine protein phosphatase 2A (PP2A). There is evidence that the PP2A-PPP2R5D complex is involved in regulating the phosphatidylinositol 3-kinase (PI3K)/AKT signalling pathway, which is crucial for several cellular processes, including the pathogenesis and progression of haemangiomas. Case presentation: We report the first PPP2R5D-related neurodevelopmental disorder case from Sardinia, a child with transient hypoglycaemia, facial dysmorphisms, and multiple haemangiomas. Whole Exome Sequencing analysis confirmed the clinical suspicion, detecting the presence of the de novo missense variant c.592G>A in the PPP2R5D gene. Conclusions: Haemangiomas have never been linked to the syndromic phenotype of the PPP2R5D-associated disorder. The close correlation between the PP2A enzyme and the PI3K/AKT signalling pathway suggests the possible correlation between its dysfunction and activation of haemangiogenesis. Our report highlights a possible link between the PPP2R5D-related disorder and altered angiogenesis, characterizing diffuse haemangiomas as a possible novel phenotypic trait of this condition. [ABSTRACT FROM AUTHOR]

Staphylea bumalda leaves (SBL) are known to possess anti-inflammatory properties. However, there is a lack of clear study on the mechanisms underlying its anti-inflammatory activity. Therefore, this study aims to elucidate the mechanisms related to the anti-inflammatory effects of SBL. SBL70E effectively inhibited the production of NO, iNOS, COX-2, IL-1β, and IL-6 induced by LPS in RAW264.7 cells. SBL70E inhibited the phosphorylation of ERK1/2 and p65 in LPS-stimulated RAW264.7 cells. In addition, SBL70E suppressed LPS-mediated activation of NF-κB luciferase activity. SBL70E increased the levels of HO-1 and nuclear Nrf2. However, inhibition of p38, JNK and PI3K blocked SBL70E-mediated increase in HO-1 and nuclear Nrf2. These findings suggest that SBL70E suppresses the production of inflammatory mediators caused by LPS in RAW264.7 cells through the inhibition of ERK1/2 and NF-κB signalling and activation Nrf2/HO-1 signalling via the activation of p38, JNK, and PI3K. These findings imply that SBL70E exhibits anti-inflammatory activity. [ABSTRACT FROM AUTHOR]

The mammalian target of rapamycin (mTOR), a serine/threonine kinase, promotes cell growth and inhibits autophagy. The following two complexes contain mTOR: mTORC1 with the regulatory associated protein of mTOR (RAPTOR) and mTORC2 with the rapamycin-insensitive companion of mTOR (RICTOR). The phosphatidylinositol 3-kinase (PI3K)/Akt/mTOR signaling pathway is important in the intervertebral disk, which is the largest avascular, hypoxic, low-nutrient organ in the body. To examine gene-silencing therapeutic approaches targeting PI3K/Akt/mTOR signaling in degenerative disk cells, an in vitro comparative study was designed between small interfering RNA (siRNA)-mediated RNA interference (RNAi) and clustered regularly interspaced short palindromic repeat (CRISPR)–CRISPR-associated protein 9 (Cas9) gene editing. Surgically obtained human disk nucleus pulposus cells were transfected with a siRNA or CRISPR–Cas9 plasmid targeting mTOR, RAPTOR, or RICTOR. Both of the approaches specifically suppressed target protein expression; however, the 24-h transfection efficiency differed by 53.8–60.3% for RNAi and 88.1–89.3% for CRISPR–Cas9 (p < 0.0001). Targeting mTOR, RAPTOR, and RICTOR all induced autophagy and inhibited apoptosis, senescence, pyroptosis, and matrix catabolism, with the most prominent effects observed with RAPTOR CRISPR–Cas9. In the time-course analysis, the 168-h suppression ratio of RAPTOR protein expression was 83.2% by CRISPR–Cas9 but only 8.8% by RNAi. While RNAi facilitates transient gene knockdown, CRISPR–Cas9 provides extensive gene knockout. Our findings suggest that RAPTOR/mTORC1 is a potential therapeutic target for degenerative disk disease. [ABSTRACT FROM AUTHOR]

CD38, a nicotinamide adenine dinucleotide (NAD+) glycohydrolase, increases during infection or inflammation. Therefore, we aimed to evaluate the effects of a CD38 inhibitor (78c) on NAD+ levels, IL-1β, IL-6, TNF-α cytokine expressions, and osteoclastogenesis. The results show that treatment with 78c on murine BMMs dose-dependently reduced CD38, reversed the decline of NAD+, and inhibited IL-1β, IL-6, and TNF-α pro-inflammatory cytokine levels induced by oral pathogen Porphyromonas gingivalis (Pg) or Aggregatibacter actinomycetemcomitans (Aa) or by advanced glycation end products (AGEs). Additionally, treatment with 78c dose-dependently suppressed osteoclastogenesis and bone resorption induced by RANKL. Treatment with 78c suppressed CD38, nuclear factor kappa-B (NF-κB), phosphoinositide 3-kinase (PI3K), and mitogen-activated protein kinases (MAPKs) induced by Pg, Aa, or AGEs, and suppressed podosome components (PI3K, Pyk2, Src, F-actin, integrins, paxillin, and talin) induced by RANKL. These results from our studies support the finding that the inhibition of CD38 by 78c is a promising therapeutic strategy to treat inflammatory bone loss diseases. However, treatment with a CD38 shRNA only significantly reduced IL-1β, IL-6, and TNF-α pro-inflammatory cytokine levels induced by AGEs. Compared with controls, it had limited effects on cytokine levels induced by Pg or Aa. Treatment with the CD38 shRNA enhanced RANKL-induced osteoclastogenesis, suggesting that 78c has some off-target effects. [ABSTRACT FROM AUTHOR]

PI3Kα, consisting of the p110α isoform of the catalytic subunit of PI 3-kinase (encoded by PIK3CA) and the p85α regulatory subunit (encoded by PI3KR1) is activated by growth factor receptors. The identification of common oncogenic mutations in PIK3CA has driven the development of many inhibitors that bind to the ATP-binding site in the p110α subunit. Upon activation, PI3Kα undergoes conformational changes that promote its membrane interaction and catalytic activity, yet the effects of ATP-site directed inhibitors on the PI3Kα membrane interaction are unknown. Using FRET and biolayer interferometry assays, we show that a class of ATP-site directed inhibitors represented by GSK2126458 block the growth factor activated PI3KαWT membrane interaction, an activity dependent on the ligand forming specific ATP-site interactions. The membrane interaction for hot spot oncogenic mutations that bypass normal p85α regulatory mechanisms was insensitive to GSK2126458, while GSK2126458 could regulate mutations found outside of these hot spot regions. Our data show that the effect of GSK126458 on the membrane interaction requires the enzyme to revert from its growth factor activated state to a basal state. We find that an ATP substrate analogue can increase the wild type PI3Kα membrane interaction, uncovering a substrate based regulatory event that can be mimicked by different inhibitor chemotypes. Our findings, together with the discovery of small molecule allosteric activators of PI3Kα illustrate that PI3Kα membrane interactions can be modulated by factors related to ligand binding both within the ATP site and at allosteric sites. [ABSTRACT FROM AUTHOR]

Klinefelter syndrome (KS) is the most frequent genetic anomaly in infertile men. Given its unclear mechanism, we aim to investigate critical genes and pathways in the pathogenesis of KS based on three bulk and one single-cell transcriptome data sets from Gene Expression Omnibus. We merged two data sets (GSE42331 and GSE47584) with human KS whole blood samples. When comparing the control and KS samples, five hub genes, including defensin alpha 4 (DEFA4), bactericidal permeability increasing protein (BPI), myeloperoxidase (MPO), intelectin 1 (ITLN1), and Xg Glycoprotein (XG), were identified. Besides, infiltrated degree of certain immune cells such as CD56bright NK cell were positively associated with the expression of ITLN1 and XG. Kyoto Encyclopedia of Genes and Genomes analysis identified upregulated phosphatidylinositol 3-kinase (PI3K)/AKT pathway in KS. Gene set enrichment analysis followed by gene set variation analysis confirmed the upregulation of G2M checkpoint and heme metabolism in KS. Thereafter, the GSE200680 data set was used for external validation of the expression variation of hub genes from healthy to KS testicular samples, and each hub gene yielded excellent discriminatory capability for KS without exception. At the single-cell level, the GSE136353 data set was utilized to evaluate intercellular communication between different cell types in KS patient, and strong correlations were detected between macrophages/ dendritic cells/ NK cells and the other cell types. Collectively, we provided hub genes, pathways, immune cell infiltration degree, and cell-cell communication in KS, warranting novel insights into the pathogenesis of this disease. [ABSTRACT FROM AUTHOR]

Our objective was to test a single dose of the phosphatidylinositol 3-kinase (PI3K) inhibitor alpelisib as a tool for acute modeling of insulin resistance in healthy volunteers. This single-center double-blind phase 1 clinical trial randomly assigned healthy adults to a single oral dose of 300 mg alpelisib (n = 5) or placebo (n = 6) at bedtime, followed by measurement of glucose, insulin, and C-peptide levels after an overnight fast and during a 3-h 75-g oral glucose tolerance test (OGTT). Fasting plasma glucose trended higher with alpelisib (mean ± SD 93 ± 11 mg/dL) versus placebo (84 ± 5 mg/dL); mean fasting serum insulin increased nearly fivefold (23 ± 12 vs. 5 ± 3 μU/mL, respectively), and HOMA of insulin resistance (IR) scores were 5.4 ± 3.1 for alpelisib and 1.1 ± 0.6 for placebo. During OGTT, incremental area under the curve (AUC) for insulin was more than fourfold greater with alpelisib (22 ± 15 mU/mL × min) than with placebo (5 ± 2 mU/mL × min); glucose AUC trended higher with alpelisib. Single-dose alpelisib was well tolerated and produced metabolic alterations consistent with acute induction of IR, validating its use for mechanistic study of insulin action in humans. Article Highlights: This study addresses the paucity of experimental methods for the clinical investigation of insulin resistance in humans. We sought to determine if a single dose of the phosphatidylinositol 3-kinase (PI3K) inhibitor alpelisib reliably and tolerably induces an acute insulin-resistant state in healthy volunteers. A single dose of alpelisib versus placebo clearly induced biochemical evidence of insulin resistance both while fasting and during an oral glucose tolerance test; it was well tolerated. Our findings suggest that acute inhibition of PI3K with alpelisib is a useful tool for mechanistic studies of insulin resistance in humans. [ABSTRACT FROM AUTHOR]

PURPOSE: Patients age 1-21 years with relapsed or refractory solid and CNS tumors were assigned to phase II studies of molecularly targeted therapies on the National Cancer Institute-Children's Oncology Group (NCI-COG) Pediatric Molecular Analysis for Therapy Choice (MATCH) trial. Patients whose tumors harbored predefined genetic alterations in the phosphoinositide 3-kinase (PI3K)/mammalian target of rapamycin (mTOR) pathway and lacked mitogen-activated protein kinase pathway activating alterations were treated with the PI3K/mTOR inhibitor samotolisib. METHODS: Patients received samotolisib twice daily in 28-day cycles until disease progression or unacceptable toxicity. A rolling 6 limited dose escalation was performed as, to our knowledge, this was the first pediatric study of samotolisib. The primary end point was the objective response rate; secondary end points included progression-free survival (PFS) and the recommended phase II dose and toxicity of samotolisib in children. RESULTS: A total of 3.4% (41/1,206) of centrally tested patients were matched to this arm. Seventeen patients were treated. Among treated patients, the most common diagnoses included osteosarcoma (n = 6) and high-grade glioma (n = 5) harboring alterations in phosphatase and tensin homolog (n = 6), PIK3CA (n = 5), and tuberous sclerosis complex 2 (n = 3). No objective responses or prolonged stable disease were observed. Three-month PFS was 12% (95% CI, 2 to 31). Two patients experienced dose-limiting toxicities (mucositis and pneumonitis). Dose level 2 (115 mg/m2/dose twice daily) was determined to be the recommended phase II dose of samotolisib in children. CONCLUSION: This nationwide study was successful at identifying patients and evaluating the efficacy of molecularly targeted therapy for rare molecular subgroups of patients in a histology-agnostic fashion. Unfortunately, there was no activity of samotolisib against tumors with PI3K/mTOR pathway alterations. Prospective trials such as the NCI-COG Pediatric MATCH are necessary to evaluate the efficacy of molecularly targeted therapies given their increasing use in clinical practice. [ABSTRACT FROM AUTHOR]

Background: Altitude sickness is often prone to occur during tourism or work in high-altitude areas. In China, traditional Tibetan medicines have a long history of preventing or treating altitude sickness, especially altitude hypoxia, which may lead to myocardial cell apoptosis and myocardial hypoxia-reoxygenation injury. Purpose: This study investigated the effect of a Tibetan-origin edible Chinese herbal prescription (named C18) on protecting H9C2 cardiomyocytes from cobalt chloride-induced hypoxia injury and its potential mechanism. Materials and Methods: In this study, a hypoxic injury model of H9C2 cardiomyocytes induced by cobalt chloride was established first. Then the cell viability, relevant antioxidant indicators malondialdehyde (MDA), superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and protein expression (hypoxia-inducible factor 1 alpha (HIF-1α), phosphoinositide 3-kinase (PI3K), phosphorylated protein kinase B (p-AKT)) were measured after pretreatment with or without C18. At last, the specific PI3K/AKT inhibitor LY294002 was applied to verify the antihypoxia signaling pathway. Results: C18 could significantly promote normal H9C2 cardiomyocyte proliferation and inhibit apoptosis of hypoxic H9C2 cardiomyocytes, reduce the release of lactate dehydrogenase and MDA, and increase the levels of SOD and GSH-Px antioxidant enzymes. In addition, C18 could significantly downregulate the expression of HIF-1α protein and upregulate the expression of intracellular p-AKT. Moreover, these effects of C18 can be blocked by the specific PI3K/AKT inhibitor LY294002. Conclusion: C18 protects H9C2 cardiomyocytes from cobalt chloride-induced hypoxia injury through the PI3K/AKT signaling pathway. [ABSTRACT FROM AUTHOR]

Background: In recent years, the number of patients with myocardial ischaemia is rising year by year in China. Objectives: The study uses network pharmacology to predict targets and pathways of action of Apocynum venetum L. (AVL) for the treatment of myocardial ischemia (MI). Materials and Methods: The essential active compounds of AVL were obtained from the Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform. The objective of selecting the target genes was achieved through the utilization of GeneCards and Swiss Target Prediction resources. The pool of MI-related targets was obtained from DisGeNET, Online Mendelian Inheritance in Man and the Therapeutic Target Database. The protein-protein interaction network was meticulously constructed using the STRING algorithm. The gene ontology (GO) analysis of AVL-MI targets was performed at Metascape. In addition, Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis was conducted. Furthermore, molecular docking analysis was conducted to study the interactions of AVL components with estrogen receptor 1 (ESR1), heat shock protein 90 alpha (HSP90A), protein kinase B (Akt1), tyrosine kinase Src (SRC) and phosphatidylinositol 3-kinase (PI3K). Finally, cellular experiments were performed to validate the mechanism of action of AVL. Results: The molecular target analysis revealed that AVL has the potential to interact with a total of 147 biomolecules. This comprises ESR1, HSP90A, epidermal growth factor receptor, protein kinase B alpha (Akt1), SRC and PI3K. As indicated by GO and KEGG analyses, AVL's inhibitory potential against MI may be due to its action on the PI3K-Akt signalling pathway. Furthermore, docking studies conducted to assess the interactions between AVL components and their targets (ESR1, HSP90A, Akt1, SRC and PI3K) confirmed that they have robust binding affinities. Cell experiments also showed that AVL treatment significantly reduced oxidative stress indexes (p < 0.05). Additionally, the expression levels of Akt1 and PI3K proteins were significantly higher in the AVL group compared to the MI group (p < 0.05). Conclusion: AVL therapy exhibits the potential to alleviate the symptoms of MI by mitigating oxidative stress and by orchestrating the expression of proteins such as PI3K and Akt1. [ABSTRACT FROM AUTHOR]

The commonality between various muscle diseases is the loss of muscle mass, function, and regeneration, which severely restricts mobility and impairs the quality of life. With muscle stem cells (MuSCs) playing a key role in facilitating muscle repair, targeting regulators of muscle regeneration has been shown to be a promising therapeutic approach to repair muscles. However, the underlying molecular mechanisms driving muscle regeneration are complex and poorly understood. Here, we identified a new regulator of muscle regeneration, Deaf1 (Deformed epidermal autoregulatory factor-1) – a transcriptional factor downstream of foxo signaling. We showed that Deaf1 is transcriptionally repressed by FOXOs and that DEAF1 targets to Pik3c3 and Atg16l1 promoter regions and suppresses their expression. Deaf1 depletion therefore induces macroautophagy/autophagy, which in turn blocks MuSC survival and differentiation. In contrast, Deaf1 overexpression inactivates autophagy in MuSCs, leading to increased protein aggregation and cell death. The fact that Deaf1 depletion and its overexpression both lead to defects in muscle regeneration highlights the importance of fine tuning DEAF1-regulated autophagy during muscle regeneration. We further showed that Deaf1 expression is altered in aging and cachectic MuSCs. Manipulation of Deaf1 expression can attenuate muscle atrophy and restore muscle regeneration in aged mice or mice with cachectic cancers. Together, our findings unveil an evolutionarily conserved role for DEAF1 in muscle regeneration, providing insights into the development of new therapeutic strategies against muscle atrophy. Abbreviations: DEAF1: Deformed epidermal autoregulatory factor-1; FOXO: Forkhead box O; MuSC: Muscle Stem Cell; PAX7: Paired box 7; PIK3C3: Phosphatidylinositol 3-kinase catalytic subunit type 3. [ABSTRACT FROM AUTHOR]

Background: Chronic chagasic cardiomyopathy is the most severe clinical manifestation of Chagas disease, which affects approximately seven million people worldwide. Latin American countries bear the highest burden, with the greatest morbidity and mortality rates. Currently, diagnostic methods do not provide information on the risk of progression to severe stages of the disease. Recently, microRNAs (miRNAs) have been proposed as promising tools for monitoring the progression of Chagas disease. This study aimed to analyze the expression profiles of the miRNAs miR-1, miR-16, miR-208, and miR-208b in cardiac tissue, plasma, and plasma extracellular vesicles from Ninoa TcI-infected mice during the acute and indeterminate phases of Chagas disease. Methods: The cardiac-specific miRNAs and miR-16 levels were examined in all samples using RT-qPCR. Additionally, pathway analysis was performed to investigate the impact of potential miRNA target genes across various databases. Results: Elevated miR-208b expression was observed in cardiac tissue and plasma during the acute phase. Bioinformatic analysis identified three pathways implicated in disease progression: phosphatidylinositol 3-kinase signaling, Fc gamma receptor-mediated phagocytosis, and leukocyte transendothelial migration, as well as cholinergic synapse pathways. Conclusions: MiR-208b was upregulated during the acute phase and downregulated in the indeterminate phase, suggesting it may play a crucial role in disease progression. [ABSTRACT FROM AUTHOR]

AKT, or protein kinase B, is a central node of the PI3K signaling pathway that is pivotal for a range of normal cellular physiologies that also underlie several pathological conditions, including inflammatory and autoimmune diseases, overgrowth syndromes, and neoplastic transformation. These pathologies, notably cancer, arise if either the activity of AKT or its positive or negative upstream or downstream regulators or effectors goes unchecked, superimposed on by its intersection with a slew of other pathways. Targeting the PI3K/AKT pathway is, therefore, a prudent countermeasure. AKT inhibitors have been tested in many clinical trials, primarily in combination with other drugs. While some have recently garnered attention for their favorable profile, concern over resistance and off-target effects have continued to hinder their widespread adoption in the clinic, mandating a discussion on alternative modes of targeting. In this review, we discuss isoform-centric targeting that may be more effective and less toxic than traditional pan-AKT inhibitors and its significance for disease prevention and treatment, including immunotherapy. We also touch on the emerging mutant- or allele-selective covalent allosteric AKT inhibitors (CAAIs), as well as indirect, novel AKT-targeting approaches, and end with a briefing on the ongoing quest for more reliable biomarkers predicting sensitivity and response to AKT inhibitors, and their current state of affairs. [ABSTRACT FROM AUTHOR]

Background: Dietary cholesterol promotes metabolic dysfunction-associated steatohepatitis (MASH), with hepatic macrophages central to disease pathology. However, the mechanisms by which cholesterol-loaded macrophages influence MASH remain unclear. Methods: In this study, mice were fed a cholesterol-rich choline-deficient, L-amino acid-defined, high-fat diet (CDAHFD). Hepatic cholesterol levels, inflammatory markers, and pro-inflammatory macrophage polarization were assessed. In vitro studies examined the impact of cholesterol on macrophage polarization, identifying 7-dehydrocholesterol reductase (DHCR7) as a key cholesterol- and inflammation-responsive enzyme. DHCR7 expression in macrophages from MASH patients and model mice was evaluated. Functional studies involving in vitro knockdown and overexpression experiments, were complemented using myeloid-specific DHCR7 knockout mice. RNA sequencing was performed on liver tissues from wild-type and DHCR7 knockout mice to identify affected signaling pathways. Results: CDAHFD-fed mice exhibited local cholesterol accumulation and a pro-inflammatory macrophage phenotype in the liver. Cholesterol overload in vitro promoted M1 polarization and liver inflammation, reversible by simvastatin. DHCR7 expression, responded to cholesterol and polarization state, was downregulated in M1-polarized and hepatic macrophages from MASH patients and mice. DHCR7 suppression promoted pro-inflammatory phenotype, while its overexpression showed anti-inflammatory effects. Myeloid-specific DHCR7 deficiency in CDAHFD-fed mice worsened liver inflammation and pro-inflammatory macrophage infiltration. RNA sequencing identified the phosphoinositide 3-kinase (PI3K) pathway in DHCR7-regulated effects, with DHCR7-PI3K axis activation mitigating cholesterol-driven inflammation. Conclusions: These findings unveil novel mechanistic insights into MASH pathogenesis, suggesting targeting macrophage-specific DHCR7 activation may offer a promising therapeutic strategy for MASH. [ABSTRACT FROM AUTHOR]

Tumor-associated macrophages (TAMs) recapitulate the developmental and homeostatic behaviors of tissue resident macrophages (TRMs) to promote tumor growth, invasion and metastasis. TRMs arise in the embryo and colonize developing tissues, initially to guide tissue morphogenesis and then to form complex networks in adult tissues to constantly search for threats to homeostasis. The macrophage growth factor, colony-stimulating factor-1 (CSF-1), which is essential for TRM survival and differentiation, is also responsible for the development of the unique motility machinery of mature macrophages that underpins their ramified morphologies, migratory capacity and ability to degrade matrix. Two CSF-1-activated kinases, hematopoietic cell kinase and the p110δ catalytic isoform of phosphatidylinositol 3-kinase, regulate this machinery and selective inhibitors of these proteins completely block macrophage invasion. Considering tumors co-opt the invasive capacity of TAMs to promote their own invasion, these proteins are attractive targets for drug development to inhibit tumor progression to invasion and metastasis. [ABSTRACT FROM AUTHOR]

The class I phosphatidylinositol 3-kinase (PI3K)-AKT signaling pathway is a key regulator of cell survival, growth, and proliferation and is among the most frequently mutated pathways in cancer. However, where and how PI3K-AKT signaling is spatially activated and organized in mammalian cells remains poorly understood. Here, we identify focal adhesions (FAs) as subcellular signaling hubs organizing the activation of PI3K-PI(3,4,5)P 3 -AKT signaling in human cancer cells containing p110α mutations under basal conditions. We find that class IA PI3Ks are preferentially recruited to FAs for activation, resulting in localized production of PI(3,4,5)P 3 around FAs. As the effector protein of PI(3,4,5)P 3 , AKT1 molecules are dynamically recruited around FAs for activation. The spatial recruitment/activation of the PI3K-PI(3,4,5)P 3 -AKT cascade is regulated by activated FA kinase (FAK). Furthermore, combined inhibition of p110α and FAK results in a more potent inhibitory effect on cancer cells. Thus, our results unveil a growth-factor independent, compartmentalized organization mechanism for PI3K-PI(3,4,5)P 3 -AKT signaling. [Display omitted] • Class IA PI3Ks are preferentially recruited to focal adhesions for activation • PI(3,4,5)P 3 is generated and enriched around focal adhesions • AKT1 is dynamically recruited around focal adhesions by PI(3,4,5)P 3 • FAK regulates the spatial organization of PI3K-PI(3,4,5)P 3 -AKT signaling Wang et al. uncover a growth-factor-independent, compartmentalized organization mechanism for PI3K-PI(3,4,5)P 3 -AKT signaling in mammalian cells. The preferential recruitment of class IA PI3K to focal adhesions leads to localized generation and enrichment of PI(3,4,5)P 3 , resulting in dynamic recruitment and activation of AKT1 around focal adhesions in cells under basal conditions. [ABSTRACT FROM AUTHOR]

Roundabout (ROBO) 1 and 2 are transmembrane receptors that bind secreted SLIT ligands through their extracellular domains (ECDs) and signal through their cytoplasmic domains to modulate the cytoskeleton and regulate cell migration, adhesion, and proliferation. SLIT-ROBO signaling regulates pathological ocular neovascularization, which is a major cause of vision loss worldwide, but pharmacological tools to prevent SLIT-ROBO signaling are lacking. Here, we developed human monoclonal antibodies (mAbs) against the ROBO1 and ROBO2 ECDs. One antibody that inhibited in vitro SLIT2 signaling through ROBO1 and ROBO2 (anti-ROBO1/2) also reduced ocular neovascularization in oxygen-induced retinopathy (OIR) and laser-induced corneal neovascularization (CNV) mouse models in vivo. Single-cell RNA sequencing of OIR retinas revealed that antibody treatment affected several cell types relevant to physiological and pathological angiogenesis, including endothelial cells, pericytes, and a heterogeneous population of myeloid cells. mAb treatment improved blood-retina barrier integrity and prevented pathological pericyte activation in OIR. SLIT-ROBO signaling inhibition prevented pathological activation of myeloid cells and increased neuroprotective myeloid populations normally seen in the developing retina. Microglia/infiltrating macrophage–specific ablation of Robo1 and Robo2 or knockout of the downstream effector phosphatidylinositol 3-kinase (Pik3cg) encoding PI3Kγ in both OIR and CNV models phenocopied anti-ROBO1/2 treatment, further demonstrating the key role of myeloid cells as drivers of ocular neovascular diseases. ROBO1/2 blocking antibodies may thus provide a promising strategy to combat inflammation in blinding eye diseases. Editor's summary: Ocular neovascularization underlies blindness in several pathological conditions. Current treatments focus on inhibiting vascular endothelial growth factor A (VEGFA) signaling, but targeting other pathways in diverse cell types could improve therapies. Geraldo et al. developed human monoclonal antibodies (mAbs) targeting Roundabout (ROBO) receptors that regulate cell migration and proliferation to target ocular neovascularization. mAb treatment in an oxygen-induced retinopathy mouse model and in laser-induced corneal neovascularization reduced neovascular area and increased myeloid cell populations associated with retinal development. Combining mAb treatment with standard anti-VEGFA treatment further improved pathology. Genetically deleting Robo1 and 2 in microglia and infiltrating macrophages mimicked the mAb treatment. These results demonstrate how inhibiting ROBO signaling in myeloid cells could be a strategy to treat ocular neovascularization diseases. —Brandon Berry [ABSTRACT FROM AUTHOR]

Thyroid cancer (TC) is the most common endocrine cancer, which contributes to more than 43,600 deaths and 586,000 cases worldwide every year. Among the TC types, PTC and FTC comprise 90% of all TCs. Genetic modifications in genes are responsible for encoding proteins of mitogen-associated protein kinase cascade, which is closely related with numerous cellular mechanisms, including controlling programmed cell death, differentiation, proliferation, gene expression, as well as in genes encoding the PI3K (phosphatidylinositol 3-kinase)/protein kinase B (AKT) cascade, which has contribution in controlling cell motility, adhesion, survival, and glucose metabolism, have been associated with the TC pathogenesis. Various genetic modifications including BRAF mutations, RAS mutations, RET mutations, paired-box gene 8/peroxisome proliferator-activated receptor-gamma fusion oncogene, RET/PTC rearrangements, telomerase reverse transcriptase mutations, neurotrophic tyrosine receptor kinase fusion genes, TP53 mutations, and eukaryotic translation initiation factor 1A X-linked mutations can effectively serve as potential biomarkers in both diagnosis and prognosis of TC. On the other hand, epigenetic modifications can lead to aberrant functions or suppression of a range of signalling cascades, which can ultimately result in cancer. Various studies have observed the link between epigenetic modification and multiple cancers including TC. It has been reported that several epigenetic alterations including histone modifications, aberrant DNA methylation, and epigenetic modulations of non-coding RNAs can play significant roles as potential biomarkers in the diagnosis and prognosis of TC. Therefore, a good understanding regarding the genetic and epigenetic modifications is not only essential for the diagnosis and prognosis of TC, but also for the development of novel therapeutics. In this review, most of the major TC-related genetic and epigenetic modifications and their potential as biomarkers for TC diagnosis and prognosis have been extensively discussed. [ABSTRACT FROM AUTHOR]

Lymphatic vessels grow through active sprouting and mature into a vascular complex that includes lymphatic capillaries and collecting vessels that ensure fluid transport. However, the signaling cues that direct lymphatic sprouting and patterning remain unclear. In this study, we demonstrate that chemokine signaling, specifically through CXCL12 and CXCR4, plays crucial roles in regulating lymphatic development. We show that LEC-specific Cxcr4-deficient mouse embryos and CXCL12 mutant embryos exhibit severe defects in lymphatic sprouting, migration and lymphatic valve formation. We also discovered that CXCL12, originating from peripheral nerves, directs the migration of dermal lymphatic vessels to align with nerves in developing skin. Deletion of Cxcr4 or blockage of CXCL12 and CXCR4 activity results in reduced VEGFR3 levels on the LEC surface. This, in turn, impairs VEGFC-mediated VEGFR3 signaling and downstream PI3K and AKT activities. Taken together, these data identify previously unknown chemokine signaling originating from peripheral nerves that guides dermal lymphatic sprouting and patterning. Our work identifies for the first time a neuro-lymphatics communication during mouse development and reveals a previously unreported mechanism by which CXCR4 modulates VEGFC, VEGFR3 and AKT signaling. [ABSTRACT FROM AUTHOR]

Ultraviolet (UV) rays prompt a natural response in epidermal cells, particularly within melanocytes. The changes in gene expression and related signaling pathways in melanocytes following exposure to UV radiation are still not entirely understood. Our findings reveal that UVB irradiation suppresses the expression of Dicer (also known as Dicer1). This repression is intricately linked to the activation of the phosphoinositide 3-kinase (PI3K), ribosomal S6 kinase (RSK) and Wnt-β-catenin signaling pathways, and is directly associated with transcriptional repression by β-catenin (also known as CTNNB1). Notably, we have identified specific binding sites for the TCF/LEF-β-catenin complex in the Dicer promoter. Collectively, these results emphasize the significance of the UV-induced pathway involving the TCF/LEF-β-catenin complex, which impacts Dicer expression. UV radiation also reduced the levels of specific microRNAs known to be important in the biology of melanocytes. This pathway holds potential importance in governing melanocyte physiology. [ABSTRACT FROM AUTHOR]