Search Results (162)

Protein kinase inhibition can be achieved through various mechanisms, including blocking phosphorylation activity or disrupting regulatory interactions. While small molecule inhibitors have shown promise, their selectivity remains challenging due to the structural similarities among kinase catalytic sites. To design selective kinase inhibitors based on peptide terminal tail interactions with the activation segment, focusing on five kinases with different conformational states: GSK3, PAK4, TTN (OUT conformation) and PKB, FLT3 (IN conformation). Three-dimensional structures from RCSB PDB were optimized using MODELLER version 9.0. Peptide sequences were designed with PeptiDerive (Rosetta) and RosettaDesign version 3.5, followed by pharmacophore modeling based on key interaction residues. Virtual screening was then conducted with PyRx 0.8 and molecular docking with AutoDock Vina 1.1.2. Molecular dynamics simulations were performed using Desmond v6.6 (Schrödinger Suite 2016, Multisim v3.8.5.19) (100 ns, NPT ensemble, 300 K). Analysis of the five kinases revealed distinct interaction profiles with designed peptidomimetic compounds. Kinases displaying the IN conformation of the activation segment (PKB and FLT3) consistently showed superior stability and stronger interaction profiles compared to those in the OUT conformation. The designed compounds formed key hydrogen bonds and hydrophobic interactions with critical residues in the activation segment binding pocket. The most promising inhibitors demonstrated stability throughout the molecular dynamics simulations, with IN conformation kinases maintaining more consistent conformational profiles than their OUT conformation counterparts. Kinases with IN conformation of the activation segment demonstrated superior stability and interaction profiles compared to OUT conformations. These findings contribute to our understanding of selective kinase inhibition and provide a framework for developing novel inhibitors, particularly for PKB and FLT3. The implications of this study extend to rational drug design approaches that leverage natural regulatory mechanisms for therapeutic intervention, though further optimization is needed for GSK-3β, PAK4, and TTN to improve stability and binding affinity. Full article

Myocardial ischemia–reperfusion injury remains a major unresolved challenge in cardiovascular medicine. Although timely restoration of blood flow is essential to limit ischemic damage, reperfusion triggers a complex network of maladaptive biological responses, including oxidative stress, calcium overload, mitochondrial dysfunction, metabolic impairment, and sterile inflammation. These processes converge on cardiomyocyte death, adverse ventricular remodeling, and long-term functional deterioration. Mesenchymal stem cells have been widely investigated as cardioprotective agents; however, accumulating evidence indicates that their beneficial effects are predominantly mediated by paracrine mechanisms. Among these, extracellular vesicles released by mesenchymal stem cells have emerged as key biological effectors. Experimental studies demonstrate that mesenchymal stem cell–derived extracellular vesicles modulate multiple signaling pathways involved in ischemia–reperfusion injury, including activation of the phosphoinositide 3-kinase (PI3K) and protein kinase B (PKB) axis, regulation of signal transducer and activator of transcription 3 (STAT3) signaling in a cell-specific manner, suppression of nuclear factor kappa B (NF-κB)-driven inflammatory responses, and stabilization of hypoxia-inducible factor-1α (HIF-1α)–dependent adaptive programs. At the subcellular level, these vesicles preserve mitochondrial structure and function, support energy metabolism, regulate mitophagy, and limit oxidative damage. Their molecular cargo, comprising regulatory microRNAs, metabolic enzymes, and stress-response proteins, enables coordinated modulation of survival, inflammatory, and reparative pathways rather than single-target effects. This review synthesizes current experimental evidence on the mechanistic basis of mesenchymal stem cell–derived extracellular vesicle–mediated cardioprotection and discusses their potential as cell-free, mechanism-based therapeutic strategies to limit myocardial ischemia–reperfusion injury. Full article

Transforming growth factor-beta 1 (TGF-β1)-stimulated clone 22 domain (TSC22D) family genes (including TSC22D1-TSC22D4) were identified as transcription factors. It has been demonstrated that they display multiple functions due to proteins’ isoforms, redundancy, and other factors. Formerly, researchers mainly focused on its functions, like controlling cell growth and development, cell apoptosis, and balance of osmotic pressure in vivo. Nowadays, growing evidence indicates that they also play an important role in metabolic regulation and the immune system and are expected to be a new potential target for the treatment of diabetes or obesity. Despite this, it has been shown that TSC22D family genes have an inhibitory effect in multiple tumors. In this review, we significantly synthesized advances in metabolism, showing that TSC22D3 could control lipid accumulation via modulating adipogenesis and adipose differentiation, while TSC22D4 could regulate insulin sensitivity and gluconeogenesis by affecting Akt (serine/threonine kinase, also known as protein kinase B, or PKB) phosphorylation. Moreover, we provide novel insights, including the fact that TSC22D family genes function as a double-edged sword in cancer due to the type of tumor and tumor microenvironment (TME). Full article

This study examines how socialization costs, inspection costs, collection costs, motor vehicle tax rates (Pajak Kendaraan Bermotor, PKB), vehicle ownership transfer tax rates (Bea Balik Nama Kendaraan Bermotor, BBNKB), the Corruption Perception Index (CPI), and the Indonesian Digital Society Index (Indeks Masyarakat Digital Indonesia, IMDI) influence regional tax compliance across 34 provinces in Indonesia, using secondary data from 2020 to 2024. Guided by Fiscal Federalism, Tax Optimization Theory, and the Fischer Tax Compliance Model, the analysis integrates spatial regression and SWOT to capture both structural and spatial dynamics in provincial tax administration. The spatial error model reveals that socialization costs, PKB, and BBNKB significantly shape provincial tax compliance. At the same time, the other variables show no measurable effect. Spatial clustering indicates High–High compliance in Central Java, Low–Low compliance in South Sumatra and Lampung, and Low–High compliance in North Sumatra. The SWOT assessment places Indonesia’s provincial tax compliance strategy in Quadrant I, suggesting strong institutional capacity and substantial external opportunities to support aggressive improvement strategies. This study contributes by providing province-wide empirical evidence on the fiscal and administrative determinants of compliance and by incorporating collection costs and spatial relationships into the analysis. Policy implications include strengthening targeted socialization, improving rate-setting mechanisms, and expanding digital reporting systems to enhance taxpayer understanding and administrative transparency. Full article

Follicle selection is a pivotal process that determines which dominant prehierarchical follicle will enter the preovulatory hierarchy in the hen ovary and directly affects egg-laying productivity, in which granulosa cells (GCs) are characterized by active proliferation and significantly enhanced FSHR mRNA expression. Increasing evidence has shown that the PI3K/Akt signaling pathway and its important target and effector FOXO1, which promotes GC apoptosis, play crucial roles in ovarian follicular development in mammals. To investigate the molecular mechanism by which follicle-stimulating hormone (FSH)-mediated forkhead box O1 (FOXO1) participates in follicle selection, we treated granulosa cells from 6–8 mm prehierarchical follicles of chickens with FSH and leptomycin B (LMB). The results showed that under FSH and/or LMB treatment, the expression levels of FSHR, FOXO1, and its phosphorylated forms (p-FOXO1) at the predicted protein kinase B (PKB/Akt) phosphorylation sites Thr²⁴, Ser²⁴⁸, and Ser³¹¹ were differentially regulated. The subcellular localization of p-FOXO1 in hen ovarian GCs was determined by Western blotting and immunofluorescence staining (IF) analysis. And the expression of FOXO1 was significantly reduced, whereas the expression of p-FOXO1 corresponding to the PKB phosphorylation sites Ser²⁴⁸ and Ser³¹¹ was noticeably boosted in cultured GCs induced by FSH, accompanied by exclusion of FOXO1 from the nucleus to the cytoplasm. Subsequently, the effects of the PI3K/Akt signaling pathway on phosphorylation levels and nuclear exclusion of p-FOXO1 at the sites Ser²⁴⁸ and Ser³¹¹ were examined. The results indicate that the PI3K/Akt-dependent phosphorylation at these sites directly resulted in nuclear exclusion of FOXO1 in ovarian GCs, in which the Ser²⁴⁸ site is more essential than the Ser³¹¹ site. Subsequently, the FSH-induced acetylation of FOXO1 mediated by the cAMP/PKA pathway can enhance the phosphorylation level of FOXO1 at the Ser²⁴⁸ site. In summary, our findings demonstrate that FSH induces FOXO1 phosphorylation, nuclear exclusion, and functional inactivation by activating the PI3K/Akt signaling pathway. Moreover, during follicular development and selection, FOXO1 acts as a pivotal mediator linking the PI3K/Akt and P62/Keap1/Nrf2 signaling pathways to regulate granulosa cell proliferation and apoptosis, thereby exerting a central regulatory role. Full article

Zoledronic acid (ZA), a nitrogen-containing bisphosphonate, is widely used to treat osteoporosis and bone metastases. However, its clinical application is limited by adverse effects, notably bisphosphonate-related osteonecrosis of the jaw (BRONJ), which is associated with cytotoxicity in oral mucosal cells. Polydeoxyribonucleotide (PDRN), a salmon sperm-derived DNA polymer with regenerative and anti-inflammatory properties, has shown therapeutic potential in tissue repair; however, its ability to mitigate ZA-induced cytotoxicity remains poorly understood. Here, we investigated the molecular mechanisms of ZA-induced toxicity in HGF-1 cells, a human gingival fibroblast line, and evaluated the protective effects of PDRN. ZA treatment (50 µM, 48 h) significantly inhibited HGF-1 cell growth, accompanied by reduced phosphorylation of protein kinase B (PKB) and signal transducer and activator of transcription 3 (STAT-3), along with increased phosphorylation of TANK-binding kinase 1 (TBK1). TBK1 silencing restored cell growth under ZA exposure, whereas silencing PKB or STAT-3 further suppressed cell growth even without ZA. Co-treatment with PDRN (100 µg/mL) effectively prevented and reversed ZA-induced HGF-1 cytotoxicity. Mechanistically, PDRN inhibited ZA-induced TBK1 phosphorylation and partially restored PKB phosphorylation, though it did not reverse the reduction in p-STAT-3. Additionally, ZA significantly elevated intracellular reactive oxygen species (ROS) levels at 8 h, which were attenuated by PDRN. The antioxidant N-acetylcysteine (NAC) similarly reduced ZA-induced ROS and p-TBK1 levels and improved cell growth, although it had limited effects on p-PKB at 8 h. Importantly, delayed PDRN treatment following ZA exposure reversed ZA-induced cell growth inhibition and TBK1 activation in a dose- and time-dependent manner. In summary, these findings demonstrate that ZA suppresses HGF-1 cell growth through ROS production, TBK1 activation, and inhibition of PKB and STAT-3, whereas PDRN counteracts these effects primarily by suppressing TBK1 activation and oxidative stress. Full article

Acacetin, a naturally occurring flavonoid, has attracted increasing attention due to its broad anticancer potential. In vitro and in vivo studies using diverse tumor models have demonstrated that acacetin modulates oncogenic signaling, suppresses angiogenesis, and induces apoptosis and other regulated cell death pathways. With the rising demand for multi-target therapeutics, network pharmacology and molecular docking have emerged as powerful tools to unravel the complex molecular mechanisms of phytochemicals. Unlike previous reviews that have mainly focused on single pathways or limited cancer contexts, this review emphasizes novelty by integrating network pharmacology with molecular docking and explicitly linking these computational predictions to experimental validation, thereby identifying epidermal growth factor receptor (EGFR), signal transducer and activator of transcription 3 (STAT3), and the serine/threonine kinase AKT (also known as protein kinase B (PKB) as central experimentally supported targets. This integrative framework maps acacetin’s multi-target anticancer mechanisms and clarifies its translational opportunities for future therapeutic development. Full article

The regulation of T cell-mediated immune responses is essential for maintaining immune homeostasis and preventing autoimmune diseases. In multiple sclerosis (MS), impaired immunoregulatory control allows autoreactive T cells to persist, as effector T cells (Teff) display reduced susceptibility to regulatory T cells (Treg). This resistance to Treg-mediated tolerance is linked to altered IL-6 signaling and hyperactivation of protein kinase B (PKB/c-Akt). However, the mechanisms leading to increased PKB phosphorylation remain poorly understood. Here, we examined the expression of phosphatase and tensin homolog PTEN, a key phosphatase that negatively regulates PKB/c-Akt activation. We found that PTEN protein expression rapidly declines in activated Teff from MS patients. To clarify whether PTEN downregulation contributes to Treg resistance, we used PTEN-specific siRNA to modulate PTEN expression in Teff from healthy donors. PTEN knockdown resulted in accelerated IL-6 production, enhanced PKB phosphorylation, and reduced responsiveness to Treg-mediated suppression, similar to Treg resistance observed in MS. This study reports disrupted PTEN expression in activated Teff from MS patients. Our findings highlight that PTEN is critical for effective immune regulation of T cells, and suggest its dysregulation contributes to impaired immune tolerance in MS. Full article

Background/Objectives: Allergens can trigger severe immune responses in hypersensitive individuals, with mast cells releasing inflammatory mediators via IgE-FcɛRI signaling. Spleen tyrosine kinase (Syk) is a key regulator in this pathway, making it a promising therapeutic target. Natural modulators of Syk-mediated mast cell activation remain underexplored. This study investigated the anti-allergic effects of a 70% ethanol extract of Salvia miltiorrhiza (SME) using in vitro and in vivo models. Methods: SME was evaluated using IgE-sensitized RBL-2H3 cells, a passive cutaneous anaphylaxis model, and a DNCB-induced atopic dermatitis-like mouse model. Allergic responses were assessed via degranulation assays, histopathology, serum IgE levels, and the spleen index. Results: SME significantly inhibited mast cell degranulation by 44.4 ± 1.6% in RBL-2H3 cells at 100 µg/mL following 30 min of treatment compared to the untreated control. Western blot analysis demonstrated dose-dependent suppression of protein kinase B (PKB, also known as AKT), c-Jun N-terminal kinase (JNK), extracellular signal-regulated kinase (ERK), and spleen tyrosine kinase (Syk) phosphorylation, indicating inhibition of key allergic signaling pathways. In an IgE/Ag-induced passive cutaneous anaphylaxis model in ICR mice, SME (100 mg/kg, orally) significantly attenuated vascular permeability, as evidenced by a 20.6 ± 9.7% reduction in Evans blue extravasation relative to the Ag-treated group. In a 1-chloro-2,4-dinitrobenzene (DNCB)-induced atopic dermatitis (AD)-like model, six treatments of SME significantly improved the skin condition, reduced spleen enlargement associated with allergic inflammation, and decreased serum IgE levels by 43.3 ± 11.2% compared to the DNCB group. Conclusions: These findings suggest that SME may help to alleviate allergic responses and AD by modulating key immune signaling pathways. Full article

Epithelial differentiation and function are tightly coupled to the keratin intermediate filament cytoskeleton. Keratin filaments are unique among the cytoskeletal filament systems in terms of biochemical properties, diversity and turnover mechanisms supporting epithelial plasticity in response to a multitude of environmental cues. Epidermal growth factor (EGF) is such a cue. It is not only intricately intertwined with epithelial physiology but also modulates keratin filament network organization by increasing keratin filament turnover. The involved EGF receptor (EGFR)-dependent intracellular signaling cascades, however, have not been identified to date. We therefore tested the effect of selective inhibitors of downstream effectors of the EGFR on keratin filament turnover using quantitative fluorescence recovery after photobleaching experiments as readouts. We find that SRC and ERK kinases are involved in the regulation of keratin filament turnover, whereas PI3K/AKT and FAK have little or no effect. The identification of SRC and ERK as major keratin filament regulators extends beyond EGF signaling since they are also activated by other signals and stresses. Our data unveil a mechanism that allows modification of the properties of keratin filaments at very high temporal and spatial acuity. Full article

As the primary active component of Astragalus membranaceus, Astragaloside IV (AS-IV) is widely recognized in pharmacological research for its multifaceted therapeutic potential, particularly its antioxidative, immunostimulatory, and cardioprotective properties. Oxidative stress is an important mechanism in the induction of many diseases. The present study investigates the antioxidative mechanism of Astragaloside IV in zebrafish, using menaquinone exposure to induce oxidative stress conditions. The findings revealed that AS-IV effectively attenuated oxidative stress-induced mortality and morphological abnormalities in zebrafish. AS-IV exhibited a concentration-dependent protective effect against developmental abnormalities, with progressive reduction in pericardial effusion, body curvature, and growth retardation observed at higher doses. Moreover, AS-IV treatment not only effectively reduced reactive oxygen species (ROS) accumulation and attenuated oxidative DNA damage but also significantly decreased apoptosis in the cardiac region of zebrafish embryos under oxidative stress conditions. Western blot analysis revealed that AS-IV treatment significantly reduced the protein levels of both Cleaved Caspase-3 and γ-H2AX, indicating its ability to inhibit DNA damage-induced apoptosis. AS-IV mediates its antioxidant defense mechanisms through the activation of the nuclear factor erythroid 2-related factor 2 (NRF2) signaling pathway, inducing the significant upregulation of cytoprotective enzymes. This molecular mechanism underlies the observed phenotypic improvements in oxidative stress-related damage. Upstream analysis demonstrated that AS-IV activates NRF2 primarily through protein kinase B (AKT/PKB) pathway modulation, independent of KEAP1 regulation. Comprehensive mechanistic analysis reveals that Astragaloside IV mitigates oxidative stress-induced apoptosis in zebrafish through coordinated regulation of the AKT/NRF2/HO-1/Caspase-3 signaling axis. Full article

Metabolic syndrome (MetS) poses considerable toxicological risks due to its association with an increased likelihood of metabolic dysfunction-associated steatotic liver disease (MASLD), and is characterized by hypertension, hyperglycemia, dyslipidemia, and obesity. This study aimed to investigate the therapeutic potential of flavonoid-rich lotus seedpod extract (LSE) in alleviating MetS and MASLD-related hepatic disturbances. In vivo, mice subjected to a high-fat diet (HFD) and streptozotocin (STZ) injection were supplemented with LSE or simvastatin for 6 weeks. Obesity indicators included body weight and epididymal fat, while insulin resistance was measured by fasting serum glucose, serum insulin, homeostasis model assessment–insulin resistance index (HOMA-IR), and oral glucose tolerance (OGTT). Also, the levels of serum lipid profiles and blood pressure were evaluated. Adipokines, proinflammatory cytokines, liver fat droplets, and peri-portal fibrosis were analyzed to clarify the mechanism of MetS. LSE significantly reduced the HFD/STZ-induced MetS markers better than simvastatin, as demonstrated by hypoglycemic, hypolipidemic, antioxidant, and anti-inflammatory effects. In vitro, LSE improved oleic acid (OA)-triggered phenotypes of MASLD in hepatocyte HepG2 cells by reducing lipid accumulation and enhancing cell viability. This effect might be mediated through proteins involved in lipogenesis that are downregulated by adenosine monophosphate-activated protein kinase (AMPK). In addition, LSE reduced reactive oxygen species (ROS) generation and glycogen levels, as demonstrated by enhancing insulin signaling involving reducing insulin receptor substrate-1 (IRS-1) Ser307 phosphorylation and increasing glycogen synthase kinase 3 beta (GSK3β) and protein kinase B (PKB) expression. These benefits were dependent on AMPK activation, as confirmed by the AMPK inhibitor compound C. These results indicate that LSE exhibits protective effects against MetS-caused toxicological disturbances in hepatic carbohydrate and lipid metabolism, potentially contributing to its efficacy in preventing MASLD or MetS. Full article

Receptor-mediated endocytosis (RME) is a commonly recognized receptor internalization process of receptor degradation or recycling. However, recent studies have supported that RME is closely related to signal propagation and amplification from the plasma membrane to the cytosol. Few studies have elucidated the role of H₂O₂, a mild oxidant among reactive oxygen species (ROS) in RME and second messenger of signal propagation. In the present study, we investigated the regulatory function of H₂O₂ in early endosomes during signaling throughout receptor-mediated endocytosis. In mammalian cells with a physiological amount of H₂O₂ generated during epidermal growth factor (EGF) activation, fluorescence imaging showed that the levels of two activating phosphorylations on Ser⁴⁷³ and Thr³⁰⁸ of Akt were transiently increased in the plasma membrane, but the predominant p-Akt on Ser⁴⁷³ appeared in early endosomes. To examine the role of endosomal H₂O₂ molecules as signaling mediators of Akt activation in endosomes, we modulated endosomal H₂O₂ through the ectopic expression of an endosomal-targeting catalase (Cat-Endo). The forced removal of endosomal H₂O₂ inhibited the Akt phosphorylation on Ser⁴⁷³ but not on Thr³⁰⁸. The levels of mSIN and rictor, two components of mTORC2 that work as a kinase in Akt phosphorylation on Ser⁴⁷³, were also selectively diminished in the early endosomes of Cat-Endo-expressing cells. We also observed a decrease in the endosomal level of the adaptor protein containing the PH domain, the PTB domain, and the Leucine zipper motif 1 (APPL1) protein, which is an effector of Rab5 and key player in the assembly of signaling complexes regulating the Akt pathway in Cat-Endo-expressing cells compared with those in normal cells. Therefore, the H₂O₂-dependent recruitment of the APPL1 adaptor protein into endosomes was required for full Akt activation. We proposed that endosomal H₂O₂ is a promoter of Akt signaling. Full article

Background/Objectives: Percutaneous kidney biopsy (PKB) is a valuable diagnostic tool for evaluating renal masses and suspected renal cancer but carries a risk of hemorrhagic complications. This study aimed to determine whether injecting a hemostatic Gelfoam mixture into the biopsy tract reduces post-procedural bleeding while maintaining diagnostic accuracy. Methods: This retrospective study included 500 patients who underwent PKB at our hospital between 2019 and 2024. Patients were equally divided into two groups: Group A (n = 250) received Gelfoam injection into the biopsy tract, and Group B (n = 250) underwent standard PKB without Gelfoam. Hemorrhagic complications were categorized as mild, mild–moderate, moderate, or severe based on immediate and 4-h post-procedure CT findings. Management protocols included same-day discharge for mild cases (with next-day re-evaluation) and 24-h observation for mild–moderate cases. Results: Group A had significantly fewer moderate–severe hemorrhages compared to Group B (1.3% vs. 4.0%, p = 0.034) and a higher rate of same-day discharge (84% vs. 40%, p < 0.05). These differences led to a notable reduction in total hospitalization days (43 vs. 167) and decreased overall costs. Diagnostic yield was similarly high in both groups (98.5% vs. 97.8%, p = 0.72). Conclusions: Gelfoam injection during PKB effectively reduces hemorrhagic complications and shortens hospital stay without compromising diagnostic accuracy. Routine use of Gelfoam—especially in high-risk patients—is supported by these findings, and further prospective studies are recommended to validate these results. Full article

The Src homology 2 domain-containing inositol 5-phosphatase 1 (SHIP1) is a multidomain protein consisting of two protein–protein interaction domains, the Src homology 2 (SH2) domain, and the proline-rich region (PRR), as well as three phosphoinositide-binding domains, the pleckstrin homology-like (PHL) domain, the 5-phosphatase (5PPase) domain, and the C2 domain. SHIP1 is commonly known for its involvement in the regulation of the PI3K/AKT signaling pathway by dephosphorylation of phosphatidylinositol-3,4,5-trisphosphate (PtdIns(3,4,5)P₃) at the D5 position of the inositol ring. However, the functional role of each domain of SHIP1 for the regulation of its enzymatic activity is not well understood. To determine the contribution of the individual domains to catalytic activity, the full-length protein was compared with truncated constructs lacking one or more domain(s), regarding the substrate turnover (k_cat) and catalytic efficiency (k_cat/K_m) towards ci8-PtdIns(3,4,5)P₃. With this approach, it was possible to verify the allosteric activation of SHIP1 mediated by the C2 domain as described previously, while the PHL domain seemed instead to have a negative effect regarding catalytic efficiency. The full-length SHIP1 clearly displayed the highest turnover and the second-highest catalytic efficiency, showing the role of the SH2 domain and PRR not only in protein–protein interactions but also in catalysis. The SH2 domain increased substrate turnover but negatively affected catalytic efficiency. The linker between the SH2 and the PHL domains decreased the turnover number but positively influenced the catalytic efficiency. The PRR increased both the substrate turnover and the protein’s catalytic efficiency. The regression analysis of the Michaelis–Menten graph revealed SHIP1 to be an allosteric enzyme, with the PRR and the linker being the most involved domains in that regard. In summary, our data indicate a complex regulation of the enzymatic activity of SHIP1 by its individual domains. While the C2 domain and PRR at the carboxy-terminus have a positive effect on enzymatic activity, the SH2 and PHL domain at the amino-terminus inhibit catalytic efficiency. Full article